Co-reporter:Li He, Zhe Wei Peng, Zhong Wei Jiang, Xue Qian Tang, Cheng Zhi Huang, and Yuan Fang Li
ACS Applied Materials & Interfaces September 20, 2017 Volume 9(Issue 37) pp:31834-31834
Publication Date(Web):August 29, 2017
DOI:10.1021/acsami.7b08476
Novel metal–organic gels (MOGs) consisting of iron (Fe3+) as the central ion and 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) as the ligand were synthesized by a mild facile strategy. The Fe(III)-containing metal–organic xerogels (Fe–MOXs), obtained after removing the solvents in MOGs, were found to exhibit outstanding performance in the catalysis of luminol chemiluminescence (CL) for the first time even in the absence of extra oxidants such as hydrogen peroxide. The possible CL mechanism was discussed according to the electro/optical measurements, including electron paramagnetic resonance (EPR), UV–vis absorption, and CL spectra, as well as the effects of radical scavengers on Fe–MOXs-catalyzed luminol CL system, suggesting that the CL emission of luminol might originate from the intrinsic oxidase-like catalytic activity of Fe–MOXs on the decomposition of dissolved oxygen. Additionally, the potential practical application of the resulting luminol–Fe–MOXs system was evaluated by the quantitative analysis of dopamine. Good linearity over the range from 0.05 to 0.6 μM was obtained with the limit of detection (LOD, 3σ) of 20.4 nM and acceptable recoveries ranging from 98.6 to 105.4% in human urine. These results may open up the promising application of novel metal–organic gels as highly effective catalysts in the field of chemiluminescence.Keywords: catalysis; chemiluminescence; detection; dopamine; luminol; metal−organic gels;
Co-reporter:Meng Li Liu, Bin Bin Chen, Rong Sheng Li, Chun Mei Li, Hong Yan Zou, and Cheng Zhi Huang
ACS Sustainable Chemistry & Engineering May 1, 2017 Volume 5(Issue 5) pp:4154-4154
Publication Date(Web):March 27, 2017
DOI:10.1021/acssuschemeng.7b00126
Dendritic copper selenides (CuSe) with hierarchical side-branches are synthesized on a large scale through a one-pot rapid, facile, and green hydrothermal route in which natural kiwi juice is employed as the reducing and coating reagent. Importantly, the CuSe have high specific surface area and excellent photocatalytic activity toward model dye malachite green (MG). The degradation rate of MG on the dendritic CuSe reaches 97% within 30 min under natural daylight irradiation. The high degradation capabilities are mainly attributed to a synergetic effect of the hierarchical side-branched structure with the strong adsorption of MG and the natural daylight-driven photocatalytic activity producing highly reactive oxygen. Thus, the dendritic CuSe will have a broad application prospect, which can be used for the treatment of the dye-contaminated wastewater.Keywords: Adsorption; Dendritic CuSe; Dye degradation; Hydrothermal synthesis; Photocatalysis;
Co-reporter:Jun Ma, Lei Zhan, Rong Sheng Li, Peng Fei Gao, and Cheng Zhi Huang
Analytical Chemistry August 15, 2017 Volume 89(Issue 16) pp:8484-8484
Publication Date(Web):July 21, 2017
DOI:10.1021/acs.analchem.7b02033
For the first time, the scattering light of noble nanoparticles was applied for the simultaneous detection of dual cancer biomarkers. Two nanoprobes with dual scattering light colors were used for the simultaneous imaging of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) based on the sandwich-type immunoassay. Since AFP can combine anti-AFP-modified gold nanoparticles, which have green scattering light under the dark-field microscopic imaging (iDFM) technique, while CEA can conjugate anti-CEA-immobilized silver nanoparticles, which have blue scattering light, the simultaneous determination of AFP and CEA can be achieved by separately counting the number of green and blue light spots in iDFM. The mutual interference between the detection processes of AFP and CEA in the dual detection was investigated, and a negligible interference was found when the concentration of the antigen was in the range of 0.5–10 ng/mL, indicating the practicability of the simultaneous sensitive detection of dual targets. Furthermore, AFP and CEA in serum samples were also quantified directly without additional sample pretreatment, demonstrating the potential applications of the developed method in clinical diagnosis.
Co-reporter:Jun Zhou;Peng Fei Gao;Hong Zhi Zhang;Gang Lei;Lin Ling Zheng;Hui Liu
Nanoscale (2009-Present) 2017 vol. 9(Issue 13) pp:4593-4600
Publication Date(Web):2017/03/30
DOI:10.1039/C6NR09452J
Imaging of light scattering plasmonic nanoparticles (PNPs) with the aid of the dark-field microscopy imaging (iDFM) technique has attracted wide attention owing to its high signal-to-noise ratio, but to improve the color resolution and contrast of dark-field microscopy (DFM) images of single light scattering PNPs in a small spectral variation environment is still a challenge. In this study, a new color analytical method for resolving the resolution and contrast in DFM images has been developed and further applied for colorimetric analysis using the digital image processing technique. The color of single light scattering PNP images is automatically coded at first with the hue values of the HSI color model, and then amplified using the MATLAB program even for marginal spectral changes, leading to significant improvement of the color resolution of DFM images and easy detection with the naked eye. As a proof of concept, this method is then applied to distinguish single PNPs with various sizes and to visually detect hepatocellular carcinoma-associated microRNA. As it greatly improved the color resolution of iDFM and its detection sensitivity, this method shows promise to serve as a better alternative for sensitive visual analysis and spectrometer-based spectral analysis.
Co-reporter:Hong Zhi Zhang;Rong Sheng Li;Peng Fei Gao;Ni Wang;Gang Lei;Jian Wang
Nanoscale (2009-Present) 2017 vol. 9(Issue 10) pp:3568-3575
Publication Date(Web):2017/03/09
DOI:10.1039/C6NR09453H
Gold nanorods (GNRs) have opened up promising applications based on their reshaping, due to the fact that a tiny change in shape or size could directly lead to optical changes. Herein, we report chemical reshaping of GNRs induced by the coupling reaction between Au, ferric chloride and thiourea. In the coupling reaction, Fe3+ oxidizes the GNRs to yield Au(I), which complexes with the thiourea ligand, lowering the Gibbs free energy of the gold species and promoting the reaction equilibrium to enable the chemical reshaping of the GNRs. This coupling reaction process was monitored using a light-scattering dark-field microscopy (DFM) imaging technique and scanning electron microscopy (SEM). The light scattering underwent a colour change from bright red to yellow and finally to green, and the GNRs underwent a morphological change from rod-shaped to fusiform and finally to spherical, which is somewhat different from the results of other chemical etching processes of GNRs. It is believed that the coupling reaction induced chemical reshaping of GNRs not only provides an alternative way to monitor the coupling reaction, but also offers a facile way to obtain a desirable GNR morphology, which is important for the preparation of fusiform nanostructures.
Co-reporter:Hong Zhi Zhang;Rong Sheng Li;Peng Fei Gao;Ni Wang;Gang Lei;Jian Wang
Nanoscale (2009-Present) 2017 vol. 9(Issue 10) pp:3568-3575
Publication Date(Web):2017/03/09
DOI:10.1039/C6NR09453H
Gold nanorods (GNRs) have opened up promising applications based on their reshaping, due to the fact that a tiny change in shape or size could directly lead to optical changes. Herein, we report chemical reshaping of GNRs induced by the coupling reaction between Au, ferric chloride and thiourea. In the coupling reaction, Fe3+ oxidizes the GNRs to yield Au(I), which complexes with the thiourea ligand, lowering the Gibbs free energy of the gold species and promoting the reaction equilibrium to enable the chemical reshaping of the GNRs. This coupling reaction process was monitored using a light-scattering dark-field microscopy (DFM) imaging technique and scanning electron microscopy (SEM). The light scattering underwent a colour change from bright red to yellow and finally to green, and the GNRs underwent a morphological change from rod-shaped to fusiform and finally to spherical, which is somewhat different from the results of other chemical etching processes of GNRs. It is believed that the coupling reaction induced chemical reshaping of GNRs not only provides an alternative way to monitor the coupling reaction, but also offers a facile way to obtain a desirable GNR morphology, which is important for the preparation of fusiform nanostructures.
Co-reporter:Hong Yan Zou;Ming Xuan Gao;Tong Yang;Qiao Ling Zeng;Xiao Xi Yang;Feng Liu;Mark T. Swihart;Na Li
Physical Chemistry Chemical Physics 2017 vol. 19(Issue 10) pp:6964-6968
Publication Date(Web):2017/03/08
DOI:10.1039/C7CP00724H
Nonstoichiometric copper chalcogenides with heavy copper vacancies can be used as an effective photo-activated catalyst for the Huisgen [3+2] cycloaddition reaction as Cu(I) can be released corresponding to holes (Cu-defects) under light irradiation. These strategies expand new possibilities for carrying out prototypical click chemistry in the presence of functional groups.
Co-reporter:Hui Liu;Yue Zhang;Jia Hui Liu;Peng Hou;Jun Zhou
RSC Advances (2011-Present) 2017 vol. 7(Issue 80) pp:50584-50590
Publication Date(Web):2017/10/30
DOI:10.1039/C7RA10130A
Nitrogen-doped carbon dots (CDs) have attracted increasing attention in the field of biochemistry and biosensors due to their high emission efficiency. Herein, Bombyx mori silk, natural fibres composed by two fibroin brins and conglutinated by sericin binder, has a high content of nitrogen, was used as raw material in the coupling of citric acid to prepare nitrogen-doped CDs using a facile one-step hydrothermal route. The as-prepared nitrogen-doped CDs are uniform with an average particle size of 5.6 nm, emit blue fluorescence with the quantum yield of 61.1%, and maintain photochemical stability in high salt concentrations and in most organic solvents. Binding experiments of the as-prepared CDs with metal ions show that the hydroxyl groups on their surface play very important role in the blue fluorescence emission, which can easily bind with Fe3+ as the consequence of fluorescence quenching, making a method for Fe3+ detection developed with high selectivity and sensitivity.
Co-reporter:Jian Wang, Rong Sheng Li, Hong Zhi Zhang, Ni Wang, Zheng Zhang, Cheng Zhi Huang
Biosensors and Bioelectronics 2017 Volume 97(Volume 97) pp:
Publication Date(Web):15 November 2017
DOI:10.1016/j.bios.2017.05.035
•PEI-CDs could complex with Cu2+ ions, leading to the fluorescence quenching of CDs via an electron transfer process.•The monitoring of the cellular activities of Cu2+ was achieved with PEI-CDs under confocal microscopic.•PEI-CDs have promising applications in inhibiting of the toxicity of copper ions.As an integral part of many important enzymes, Cu2+ is involved in a number of vital biological processes, which is linked to the oxidative damage and environmental contamination when Cu2+ is excessive. In this work, Cu2+ can be captured by the amino groups of carbon dots (CDs) to form complexes, resulting in a strong fluorescence quenching of CDs via a nonradiative electron transfer process, which offered a rapid, visual, and selective methodology for Cu2+ detection. The probe exhibited a wide response concentration range (0.01–2 μM) to Cu2+ with a detection limit of 6.7 nM. Significantly, the CDs presented excellent biocompatibility and high photostability, which were applicable for the visualization of Cu2+ dynamic invasion into living cells and Tilapia mossambica. Furthermore, the toxicity of Cu2+ ions to living cells could be inhibited with CDs by the formation of complexes.
Co-reporter:Cheng Chen, Zhu-Lian Wu, Ting-Ting Wang, Xiao-Yan Wan, ... Cheng-Zhi Huang
Chinese Chemical Letters 2017 Volume 28, Issue 7(Volume 28, Issue 7) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.cclet.2017.03.022
Highly photoluminescent nitrogen and sulfur co-doped carbon nanoparticles (CNPs) ca. 56 nm have been prepared through a green one-step hydrothermal synthesis route by using millet powder as carbon sources, in which the nitrogen and sulfur co-doping improves the photoluminescent efficiency of the CNPs. The as-prepared CNPs display excellent fluorescent properties and low biotoxicity with a relatively high quantum yield of 30.4%, which have been applied for bioimaging and highly sensitive and selective detection of iron (III) ions.By using millet powder as carbon source, photoluminescent nitrogen and sulfur co-doped carbon nanoparticles were prepared with a quantum yield of 30.4% through one-pot hydrothermal synthesis, which are highly photostable, low toxic, suitable for bioimaging and detection of Fe3+.Download high-res image (164KB)Download full-size image
Co-reporter:Xiaoyan Zhao, Mengmeng Dou, Zhihao Zhang, Duoduo Zhang, Chengzhi Huang
Biomedicine & Pharmacotherapy 2017 Volume 94(Volume 94) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.biopha.2017.07.096
The preliminary studies have shown that Dendrobium officinale possessed therapeutic effects on hypertension and atherosclerosis. Studies also reported that Dendrobium officinale polysaccharides showed antioxidant capabilities. However, little is known about its effects on myocardial cells under oxidative stress. The present study was designed to study the protective effect of Dendrobium officinale polysaccharides against H2O2-induced oxidative stress in H9c2 cells. MTT assay was carried out to determine the cell viability of H9c2 cells when pretreated with Dendrobium officinale polysaccharides. Fluorescent microscopy measurements were performed for evaluating the apoptosis in H9c2 cells. Furthermore, effects of Dendrobium officinale polysaccharides on the activities of antioxidative indicators (malondialdehyde, superoxide dismutase), reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) levels were analyzed. Dendrobium officinale polysaccharides attenuated H2O2-induced cell death, as determined by the MTT assay. Dendrobium officinale polysaccharides decreased malondialdehyde levels, increased superoxide dismutase activities, and inhibited the generation of intracellular ROS. Moreover, pretreatment with Dendrobium officinale polysaccharides also inhibited apoptosis and increased the MMP levels in H9c2 cells. These results suggested the protective effects of Dendrobium officinale polysaccharides against H2O2-induced injury in H9c2 cells. The results also indicated the anti-oxidative capability of Dendrobium officinale polysaccharides.
Co-reporter:Hui Liu;Rong Sheng Li;Jun Zhou
Analyst (1876-Present) 2017 vol. 142(Issue 22) pp:4221-4227
Publication Date(Web):2017/11/06
DOI:10.1039/C7AN01136A
N-Acetylcysteine (NAC) plays an important role in optimizing the protective ability of cells as well as in the treatment of some chronic clinical conditions. Unfortunately, current methods for determining NAC based on fluorescence assay strategies remain poorly investigated. In this study, a new fluorescence method for highly sensitive and selective detection of NAC was developed. The detection method employed the fluorescence (FL) signal of branched polyethylenimine-functionalized carbon dots (PEI-CDs) via an off–on mechanism. The detection system was based on the formation of cupric amine complexes by the reaction of Cu2+ ions with surface amino groups on PEI-CDs. The FL of PEI-CDs at 460.0 nm upon exciting at 360.0 nm was quenched as a result of electron transfer between the complexes and PEI-CDs. Upon addition of NAC to Cu2+-CD solution, electron transfer occurred from the mercapto group on NAC to Cu2+, leading to the formation of Cu+ species and the dissociation of cupric amine complexes. As a result, the FL signal of PEI-CDs was turned on since single excited electrons cannot be transferred from PEI-CDs to the cupric amine complexes. The detection limit of this method was 0.56 μM, while the linear response ranged from 5.56 μM to 277.8 μM.
Co-reporter:Bin Bin Chen;Rong Sheng Li;Meng Li Liu;Hong Zhi Zhang
Chemical Communications 2017 vol. 53(Issue 36) pp:4958-4961
Publication Date(Web):2017/05/02
DOI:10.1039/C7CC00546F
The easy fabrication of single-layered graphene quantum dots (s-GQDs) still faces challenge. Herein, we report an efficient route to fabricate s-GQDs within 5 min at room temperature by introducing a simple self-exothermic reaction. The as-prepared s-GQDs can specifically bind with aluminium ions to produce an aggregation-induced emission enhancement effect.
Co-reporter:Hongyan Zou;Tong Yang;Jing Lan;Chengzhi Huang
Analytical Methods (2009-Present) 2017 vol. 9(Issue 5) pp:841-846
Publication Date(Web):2017/02/02
DOI:10.1039/C6AY03034C
Erythrocyte-like copper sulfide nanoparticles (Cu1.8S NPs) were successfully synthesized through a facile one-step solvothermal process. The as-prepared Cu1.8S NPs exhibited localized surface plasmon resonance in the near-infrared region due to their copper deficiency, which resulted in excellent peroxidase mimetic properties. The Cu1.8S NPs were able to catalyse tetramethyl benzidine to its blue oxidized product in the presence of H2O2 following the Fenton reaction. Glutathione inhibited the peroxidase-like activity of Cu1.8S NPs by scavenging the reactive oxygen species produced in the Cu1.8S–H2O2 system. Thus a colorimetric sensing platform for glutathione was established with a linear range of 0.5–10 mM and a limit of detection of 0.06 mM based on the peroxidase mimetic activity of erythrocyte-like Cu1.8S NPs. The array was successfully used for the determination of glutathione in commercial pharmaceutical tablets.
Co-reporter:Rong Sheng Li;Peng Fei Gao;Hong Zhi Zhang;Lin Ling Zheng;Chun Mei Li;Jian Wang;Yuan Fang Li;Feng Liu;Na Li
Chemical Science (2010-Present) 2017 vol. 8(Issue 10) pp:6829-6835
Publication Date(Web):2017/09/25
DOI:10.1039/C7SC01316G
The Golgi apparatus is an essential subcellular organelle. Targeting and monitoring the Golgi change at the single-cell level over a long time scale are critical but are challenges that have not yet been tackled. Inspired by the precise Golgi positioning ability of galactosyltransferase and protein kinase D, due to their cysteine residues, we developed a method for long-term Golgi imaging. Fluorescent molecules, carbon quantum dots (CQDs) and silica nanoparticles could target the Golgi when they are modified with L-cysteine. L-Cysteine-rich chiral carbon quantum dots (LC-CQDs), which have the benefits of a high Golgi specificity from L-cysteine and excellent photostability and biocompatibility from the CQDs, are proven to be highly suitable for long-term in situ imaging of the Golgi. Investigation of the mechanism showed that free thiol groups and the L-type stereo configuration of LC-CQDs are essential for specific targeting of the Golgi. With the aid of the as-prepared LC-CQDs, the dynamic changes of the Golgi in the early stage of viral infection were visualized. The Golgi targeting and imaging strategy used in this work is beneficial for Golgi-targeted drug delivery and early diagnosis and therapy of Golgi diseases.
Co-reporter:Rong Sheng Li;Peng Fei Gao;Hong Zhi Zhang;Lin Ling Zheng;Chun Mei Li;Jian Wang;Yuan Fang Li;Feng Liu;Na Li
Chemical Science (2010-Present) 2017 vol. 8(Issue 10) pp:6829-6835
Publication Date(Web):2017/09/25
DOI:10.1039/C7SC01316G
The Golgi apparatus is an essential subcellular organelle. Targeting and monitoring the Golgi change at the single-cell level over a long time scale are critical but are challenges that have not yet been tackled. Inspired by the precise Golgi positioning ability of galactosyltransferase and protein kinase D, due to their cysteine residues, we developed a method for long-term Golgi imaging. Fluorescent molecules, carbon quantum dots (CQDs) and silica nanoparticles could target the Golgi when they are modified with L-cysteine. L-Cysteine-rich chiral carbon quantum dots (LC-CQDs), which have the benefits of a high Golgi specificity from L-cysteine and excellent photostability and biocompatibility from the CQDs, are proven to be highly suitable for long-term in situ imaging of the Golgi. Investigation of the mechanism showed that free thiol groups and the L-type stereo configuration of LC-CQDs are essential for specific targeting of the Golgi. With the aid of the as-prepared LC-CQDs, the dynamic changes of the Golgi in the early stage of viral infection were visualized. The Golgi targeting and imaging strategy used in this work is beneficial for Golgi-targeted drug delivery and early diagnosis and therapy of Golgi diseases.
Co-reporter:Meng Li Liu;Lin Yang;Rong Sheng Li;Bin Bin Chen;Hui Liu
Green Chemistry (1999-Present) 2017 vol. 19(Issue 15) pp:3611-3617
Publication Date(Web):2017/07/31
DOI:10.1039/C7GC01236E
Photoluminescent (PL) carbon dots (CDs) as a new type of carbon nanomaterial have attracted increasing attention owing to their fascinating properties. Herein, we develop a facile, energy-efficient, large-scale route to prepare highly PL CDs with a quantum yield of up to 35.3% at room temperature. These PL CDs can be further separated out into green-emissive amorphous carbon nanodots (CNDs) and yellow-emissive crystalline graphene quantum dots (GQDs) through a silica gel column. Both the as-prepared CNDs and GQDs, even when having the same particle-size distribution and chemical groups, have different degrees of surface oxidation. As characterized by X-ray photoelectron spectroscopy (XPS), the yellow-emissive crystalline GQDs have a much higher surface oxidation degree than that of the green-emissive amorphous CNDs. A further finding is that the characteristic emission peaks of the CDs show an obvious red shift from 518 nm to 543 nm with the increase in the surface oxidation degree, which can be attributed to the decrease in their band gap between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). That is, the difference in band gap is closely related to the oxidation degree of the CDs, rather than the particle size or chemical groups. Moreover, the amorphous CNDs are very easily photobleached under 140 W xenon lamp irradiation as compared to the crystalline GQDs, indicating that the photostability is dependent on the crystalline structure of the CDs, which is beneficial for the top-down design and development of suitable CDs for different application purposes.
Co-reporter:Ze Xi Liu;Bin Bin Chen;Meng Li Liu;Hong Yan Zou
Green Chemistry (1999-Present) 2017 vol. 19(Issue 6) pp:1494-1498
Publication Date(Web):2017/03/20
DOI:10.1039/C6GC03288E
Photoluminescent (PL) carbon quantum dots (CQDs), in which Cu(I) was doped stably owing to their specific zigzag edge structure, were used for catalyzing the Huisgen 1,3-dipolar cycloaddition between azides and alkynes, the prototypical reaction of “click chemistry”. The results showed the great potential of the as-prepared CQDs in catalysis chemistry applications.
Co-reporter:Rong Sheng Li;Binfang Yuan;Jia Hui Liu;Meng Li Liu;Peng Fei Gao;Yuan Fang Li;Ming Li
Journal of Materials Chemistry B 2017 vol. 5(Issue 44) pp:8719-8724
Publication Date(Web):2017/11/15
DOI:10.1039/C7TB02356A
High-affinity binding of carbon nanomaterials with nucleobases, which is still a challenge, is the basis for DNA directed assembly and sensing. In this work, boron and nitrogen co-doped single-layered graphene quantum dots (BN-SGQDs) are designed as a high-affinity platform for nucleic acid detection and imaging in living cells, which has been confirmed by density functional theory (DFT) simulation and experiments. Owing to their excellent absorption and photoluminescence ability, the high quantum yield (QY 36.5%) yellow fluorescent BN-SGQDs could act as an energy donor in the fluorescence resonance energy transfer (FRET) process for nucleic acid detection. Furthermore, this BN-SGQD based sensing platform has been successfully adopted to visualize the dynamic invasion of human immunodeficiency virus (HIV) DNA into HeLa cells. The high-affinity platform has shown potential for biosensing in complicated biological samples.
Co-reporter:Ni Wang;Ze Xi Liu;Rong Sheng Li;Hong Zhi Zhang;Jian Wang
Journal of Materials Chemistry B 2017 vol. 5(Issue 31) pp:6394-6399
Publication Date(Web):2017/08/09
DOI:10.1039/C7TB01316G
A highly sensitive and selective approach for cobalt(II) detection based on the aggregation induced emission quenching strategy, which is opposite to aggregation induced emission enhancement, was developed using graphene quantum dots (GQDs). The detection could be achieved in the range of 10 nM–5 μM and the limit of detection was 2 nM. Importantly, the as-prepared GQDs showed a specific response to cobalt(II) with excellent stability in A549 cells owing to their good biocompatibility and long-time anti-photobleaching. Thus, these environmentally and bio-friendly carbon nanomaterials were employed to visualize and monitor significant physiological changes of living cells induced by cobalt(II). This shows great potential for in vitro analysis of cobalt(II).
Co-reporter:Ni Wang;Ze Xi Liu;Rong Sheng Li;Hong Zhi Zhang;Jian Wang
Journal of Materials Chemistry B 2017 vol. 5(Issue 31) pp:6394-6399
Publication Date(Web):2017/08/09
DOI:10.1039/C7TB01316G
A highly sensitive and selective approach for cobalt(II) detection based on the aggregation induced emission quenching strategy, which is opposite to aggregation induced emission enhancement, was developed using graphene quantum dots (GQDs). The detection could be achieved in the range of 10 nM–5 μM and the limit of detection was 2 nM. Importantly, the as-prepared GQDs showed a specific response to cobalt(II) with excellent stability in A549 cells owing to their good biocompatibility and long-time anti-photobleaching. Thus, these environmentally and bio-friendly carbon nanomaterials were employed to visualize and monitor significant physiological changes of living cells induced by cobalt(II). This shows great potential for in vitro analysis of cobalt(II).
Co-reporter:Lin Chen;Ying Huang;Tian Tian Xing;LingPu Ge;Tong Yang;Bin Chen
Journal of Materials Chemistry C 2017 vol. 5(Issue 31) pp:7806-7812
Publication Date(Web):2017/08/10
DOI:10.1039/C7TC01384A
Facile detection of melamine in milk was realized through a portable multi-channel sensing device using Au nanoparticles with urchin-like structures as sensing probes. The detection mechanism was based on the aggregation of Au nano-urchins, induced by the formation of Au–N bonding with melamine. The Au nano-urchins were synthesized by a seed-mediated growth method in the presence of hydroquinone, which has the localized surface plasmon absorption at about 680 nm. The results showed that the melamine detection was environment pH dependent. The optimal melamine detection condition occurred when the pH of the BR buffer was 5.72. A better selectivity to melamine was fulfilled when compared with its structurally similar compounds: cytosine, uracil, and thymine. The multi-channel sensing device has a detection limit of 18 nM for melamine in milk, which could meet the requirement for monitoring the melamine amount in milk.
Co-reporter:Xiao Xi Yang;Chun Mei Li;Yuan Fang Li;Jian Wang
Nanoscale (2009-Present) 2017 vol. 9(Issue 41) pp:16086-16092
Publication Date(Web):2017/10/26
DOI:10.1039/C7NR06520E
The diseases attributable to viruses remain a global burden. The respiratory syncytial virus (RSV), which is considered as the major viral pathogen of the lower respiratory tract of infants, has been implicated in severe lung disease. In this contribution, we developed a β-cyclodextrin (CD) functionalized graphene oxide (GO) composite, which displayed excellent antiviral activity and could load curcumin efficiently. RSV, a negative-sense single-stranded enveloped RNA virus, was employed as a model virus to investigate the antiviral activity of multifunctional GO. Proved by the tissue culture infectious dose assay and immunofluorescence assay, the curcumin loaded functional GO was confirmed with highly efficient inhibition for RSV infection and great biocompatibility to the host cells. The results showed that the composite could prevent RSV from infecting the host cells by directly inactivating the virus and inhibiting the viral attachment, and possessed prophylactic and therapeutic effects towards the virus. Our data indicate that the composite may provide new insights into antiviral therapy for RSV infection.
Co-reporter:Xiao Xi Yang;Chun Mei Li;Yuan Fang Li;Jian Wang
Nanoscale (2009-Present) 2017 vol. 9(Issue 41) pp:16086-16092
Publication Date(Web):2017/10/26
DOI:10.1039/C7NR06520E
The diseases attributable to viruses remain a global burden. The respiratory syncytial virus (RSV), which is considered as the major viral pathogen of the lower respiratory tract of infants, has been implicated in severe lung disease. In this contribution, we developed a β-cyclodextrin (CD) functionalized graphene oxide (GO) composite, which displayed excellent antiviral activity and could load curcumin efficiently. RSV, a negative-sense single-stranded enveloped RNA virus, was employed as a model virus to investigate the antiviral activity of multifunctional GO. Proved by the tissue culture infectious dose assay and immunofluorescence assay, the curcumin loaded functional GO was confirmed with highly efficient inhibition for RSV infection and great biocompatibility to the host cells. The results showed that the composite could prevent RSV from infecting the host cells by directly inactivating the virus and inhibiting the viral attachment, and possessed prophylactic and therapeutic effects towards the virus. Our data indicate that the composite may provide new insights into antiviral therapy for RSV infection.
Co-reporter:Tong Yang;Peng Hou;Lin Ling Zheng;Lei Zhan;Peng Fei Gao;Yuan Fang Li
Nanoscale (2009-Present) 2017 vol. 9(Issue 43) pp:17020-17028
Publication Date(Web):2017/11/09
DOI:10.1039/C7NR04817C
A membrane-based fluorescent sensing platform is a facile, point-of-care and promising technique in chemo/bio-analytical fields. However, the existing fluorescence sensing films for cancer biomarkers have several problems, with dissatisfactory sensitivity and selectivity, low utilization of probes encapsulated in films as well as the tedious design of membrane structures. In this work, a novel fluorescence sensing platform is fabricated by bio-grafting quantum dots (QDs) onto the surface of electrospun nanofibers (NFs). The aptamer integrated into the QDs/NFs can result in high specificity for recognizing and capturing biomarkers. Partially complementary DNA-attached gold nanoparticles (AuNPs) are employed to efficiently hybridize with the remaining aptamer to quench the fluorescence of QDs by nanometal surface energy transfer (NSET) between them both, which are constructed for prostate specific antigen (PSA) assay. Taking advantage of the networked nanostructure of aptamer–QDs/NFs, the fluorescent film can detect PSA with high sensitivity and a detection limit of 0.46 pg mL−1, which was further applied in real clinical serum samples. Coupling the surface grafted techniques to the advanced network nanostructure of electrospun NFs, the proposed aptasensing platform can be easily extended to achieve sensitive and selective assays for other biomarkers.
Co-reporter:Peng Hou;Tong Yang;Hui Liu;Yuan Fang Li
Nanoscale (2009-Present) 2017 vol. 9(Issue 44) pp:17334-17341
Publication Date(Web):2017/11/16
DOI:10.1039/C7NR05539K
Functional engineering is a crucial prerequisite for specific and wide applications of optical probes. In this study, we proposed a facile active structure preservation (ASP) method to directly develop new self-functional graphitic carbon dots (g-CDs) through a hydrothermal synthesis route by taking ciprofloxacin hydrochloride, an antibiotic belonging to a group of fluoroquinolone drugs, as an example. To retain the functional structures of the starting materials, the reaction temperature is intentionally controlled below the decomposition temperature of the reactants that hold the functional groups. As a proof of concept, we successfully prepared g-CDs with ciprofloxacin-like structures on its surface, as identified by mass spectrometric (MS) analysis. The as-prepared g-CDs not only exhibit effective antibacterial activity towards the bacteria Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), but can also optically sense pH in the range from 5.02 to 9.91. Furthermore, the g-CDs can coordinate with aluminum ions to show a chelation-enhanced photoluminescence (CHEP) effect. These results indicate that the ASP method can be promising for engineering CDs with various properties.
Co-reporter:Lin Yang;Ming Xuan Gao;Lei Zhan;Min Gong;Shu Jun Zhen
Nanoscale (2009-Present) 2017 vol. 9(Issue 7) pp:2640-2645
Publication Date(Web):2017/02/16
DOI:10.1039/C6NR07979B
Early detection of cancer is helpful for the control and prevention of diseases. Due to the low content of cancer biomarkers in the early disease phases, however, an ultrasensitive and selective method is critical. In this contribution, an ultrasensitive surface-enhanced Raman scattering (SERS) immunoassay is newly developed with the principle of introducing a common enzyme-induced deposition (EID) reaction to coat a silver layer on the surface of gold nanoparticles and to form a core–shell nanostructure of Au@Ag. By using alkaline phosphatase (ALP) to dephosphorylate its substrate, 2-phospho-L-ascorbic acid trisodium salt (AAP), to form vitamin C, silver ions could be reduced into silver atoms and coated on the surface of the AuNPs; a greatly enhanced SERS signal was then obtained. As a proof of concept, α-fetoprotein (AFP) was detected as a target, which is a biomarker of liver cancer. Excellent analytical performance of the SERS immunoassay could be achieved in the range from 0.5 to 100 pg mL−1 with a limit of detection of 0.081 pg mL−1 (3σ). Identical results could be obtained by using the newly proposed SERS immunoassay for the clinical detection of AFP in serum samples of patients to those clinically obtained by chemiluminescence immunoassays, demonstrating the potential applications of the developed method in clinical diagnosis.
Co-reporter:Lin Ling Zheng;Chun Mei Li;Shu Jun Zhen;Yuan Fang Li
Nanoscale (2009-Present) 2017 vol. 9(Issue 23) pp:7880-7887
Publication Date(Web):2017/06/14
DOI:10.1039/C7NR02162C
Studying the cell entry pathway at the single-particle level can provide detailed and quantitative information for the dynamic events involved in virus entry. Indeed, the viral entry dynamics cannot be monitored by static staining methods used in cell biology, and thus virus dynamic tracking could be useful in the development of effective antiviral strategies. Therefore, the aim of this work was to use a quantum dot-based single-particle tracking approach to monitor the cell entry behavior of the respiratory syncytial virus (RSV) in living cells. The time-lapse fluorescence imaging and trajectory analysis of the quantum dot-labeled RSV showed that RSV entry into HEp-2 cells consisted of a typical endocytosis trafficking process. Three critical events during RSV entry were observed according to entry dynamic and fluorescence colocalization analysis. Firstly, RSV was attached to lipid rafts of the cell membrane, and then it was efficiently delivered into the perinuclear region within 2 h post-infection, mostly moving and residing into the lysosome compartment. Moreover, the relatively slow velocity of RSV transport across the cytoplasm and the formation of the actin tail indicated actin-based RSV motility, which was also confirmed by the effects of cytoskeletal inhibitors. Taken together, these findings provided new insights into the RSV entry mechanism and virus–cell interactions in RSV infection that could be beneficial in the development of antiviral drugs and vaccines.
Co-reporter:Lin Ling Zheng;Chun Mei Li;Shu Jun Zhen;Yuan Fang Li
Nanoscale (2009-Present) 2017 vol. 9(Issue 23) pp:7880-7887
Publication Date(Web):2017/06/14
DOI:10.1039/C7NR02162C
Studying the cell entry pathway at the single-particle level can provide detailed and quantitative information for the dynamic events involved in virus entry. Indeed, the viral entry dynamics cannot be monitored by static staining methods used in cell biology, and thus virus dynamic tracking could be useful in the development of effective antiviral strategies. Therefore, the aim of this work was to use a quantum dot-based single-particle tracking approach to monitor the cell entry behavior of the respiratory syncytial virus (RSV) in living cells. The time-lapse fluorescence imaging and trajectory analysis of the quantum dot-labeled RSV showed that RSV entry into HEp-2 cells consisted of a typical endocytosis trafficking process. Three critical events during RSV entry were observed according to entry dynamic and fluorescence colocalization analysis. Firstly, RSV was attached to lipid rafts of the cell membrane, and then it was efficiently delivered into the perinuclear region within 2 h post-infection, mostly moving and residing into the lysosome compartment. Moreover, the relatively slow velocity of RSV transport across the cytoplasm and the formation of the actin tail indicated actin-based RSV motility, which was also confirmed by the effects of cytoskeletal inhibitors. Taken together, these findings provided new insights into the RSV entry mechanism and virus–cell interactions in RSV infection that could be beneficial in the development of antiviral drugs and vaccines.
Co-reporter:Jian Wang, Zhu Lian Wu, Hong Zhi Zhang, Yuan Fang Li, Cheng Zhi Huang
Talanta 2017 Volume 167() pp:193-200
Publication Date(Web):15 May 2017
DOI:10.1016/j.talanta.2017.01.085
•AuNPs could be simply assembled along ctDNA chains, which is much different from the ssDNA or dsDNA.•The assembly greatly enhanced the stability of AuNPs, supplying the specific sensing of spermine.•The color change of assembly could be developed as a rapid and colorimetric assay of spermine.A selective colorimetric assay for spermine was proposed in this work. In a weak alkaline medium, the conformational structure of double-stranded calf thymus DNA (ctDNA) was loosened to install gold nanoparticles (AuNPs) into chains. While, the chain assembly of AuNPs could form cross-linking aggregates when spermine was present, which was attributed to the electrostatic interaction between the positive change of spermine and negative change both of AuNPs and ctDNA, as well as the groove binding between ctDNA and spermine. Under the optimum conditions, the aggregation degree of AuNPs was proportional to the concentration of spermine in the range of 0.1–2.0 μM with a limit of detection of 11.6 nM. More interestingly, AuNPs changed from red to purple and even to blue depending on the concentration of spermine, which could be developed as the colorimetric analysis of spermine. ctDNA-AuNPs assembly was demonstrated as a novel visual probe for the specific sensing of spermine with high specificity and sensitivity.Under a weak alkaline condition, chain assemblies of gold nanoparticles (AuNPs) were formed along calf thymus DNA (ctDNA) double strands. Then, a simple and colorimetric assay for spermine was proposed bases on the cross-linking aggregation of AuNPs assembly, which was highly stable, sensitive and selective.
Co-reporter:Lijiao Liang, Shujun Zhen, Chengzhi Huang
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2017 Volume 173() pp:99-104
Publication Date(Web):15 February 2017
DOI:10.1016/j.saa.2016.08.049
•The colorimetric determination of melamine using UTP modified AuNPs has been reported.•The concentration of melamine was quantified by naked eye or spectrometric method.•This method was simple, inexpensive, environmental friendly and highly selective.•This method was successfully used for the detection of melamine in liquid milk.A highly selective method was presented for colorimetric determination of melamine using uracil 5′-triphosphate sodium modified gold nanoparticles (UTP-Au NPs) in this paper. Specific hydrogen-bonding interaction between uracil base (U) and melamine resulted in the aggregation of AuNPs, displaying variations of localized surface plasmon resonance (LSPR) features such as color change from red to blue and enhanced localized surface plasmon resonance light scattering (LSPR-LS) signals. Accordingly, the concentration of melamine could be quantified based on naked eye or a spectrometric method. This method was simple, inexpensive, environmental friendly and highly selective, which has been successfully used for the detection of melamine in pretreated liquid milk products with high recoveries.The highly selective method was presented for colorimetric determination of melamine using uracil 5′-triphosphate sodium modified gold nanoparticles (UTP-Au NPs) based on the specific hydrogen-bonding interaction between uracil base (U) and melamine.
Co-reporter:Ming Xuan Gao, Hong Yan Zou, Yuan Fang Li, and Cheng Zhi Huang
Analytical Chemistry 2017 Volume 89(Issue 3) pp:
Publication Date(Web):January 10, 2017
DOI:10.1021/acs.analchem.6b04124
Plasmonic resonance energy transfer (PRET), which occurs between the plasmonic nanoparticles and organic dyes, has significant potential in target sensing chemistry owing to its sensitivity at the single nanoparticle level. In this contribution, by using AuNPs, which has localized surface plasmonic resonance light scattering (LSPR-LS) around 550 nm, as the donor of PRET, a general sensitive detecting strategy of ions were developed. Targets can specifically react with a ring-close structured rhodamine spirolactam, which was prepared from rhodamines in the presence of different primary amine wherein the option of the primary amine is up to the targets, forming ring-open structured rhodamine spirolactam with the strong absorption around 550 nm. This process triggered the PRET from gold nanoparticles (AuNPs) to the ring-open structured rhodamine spirolactam. As a proof of concept, Cu2+ and Hg2+ were detected by using rhodamine B hydrazide and N-(rhodamine B)lactam-ethylenediamine, respectively. With the aid of a dark field microscope, the LSPR-LS of AuNPs gets decreased within 10 min with the addition of Cu2+ or Hg2+. The scattering light spectra get red-shifted during the targets addition due to the quenching dip phenomenon. Further theoretical simulation indicated the PRET process could be aroused by the electric field diminishment of AuNPs via the interaction of rhodamine. This single nanoparticle based detecting strategy could be further applied for other anions, cations, or small organic molecules detection by simply changing the rhodamine spirolactam.
Co-reporter:Gang Lei, Peng Fei Gao, Tong Yang, Jun Zhou, Hong Zhi Zhang, Shan Shan Sun, Ming Xuan Gao, and Cheng Zhi Huang
ACS Nano 2017 Volume 11(Issue 2) pp:
Publication Date(Web):January 24, 2017
DOI:10.1021/acsnano.6b08282
Understanding the photoinduced electron transfer (PET) mechanism is vital to improving the photoelectric conversion efficiency for solar energy materials and photosensitization systems. Herein, we visually demonstrate the PET process by real-time monitoring the photoinduced chemical transformation of p-aminothiophenol (p-ATP), an important SERS signal molecule, to 4,4′-dimercaptoazobenzene on single silver nanoparticles (AgNPs) with a localized surface plasmon resonance (LSPR) spectroscopy coupled dark-field microscopy. The bidirectional LSPR scattering spectral shifts bathochromically at first and hypsochromically then, which are caused by the electron transfer delay of p-ATP, disclose the PET path from p-ATP to O2 through AgNPs during the reaction, and enable us to digitalize the corresponding electron loss and gain on the surface of AgNP at different time periods. This visualized PET process could provide a simple and efficient approach to explore the nature of PET and help to interpret the SERS mechanism in terms of p-ATP.Keywords: dark-field microscopy; localized surface plasmon resonance; p-aminothiophenol; photoinduced electron transfer; single silver nanoparticles;
Co-reporter:Peng Fei Gao, Ming Xuan Gao, Hong Yan Zou, Rong Sheng Li, Jun Zhou, Jun Ma, Qiang Wang, Feng Liu, Na Li, Yuan Fang Li and Cheng Zhi Huang
Chemical Science 2016 vol. 7(Issue 8) pp:5477-5483
Publication Date(Web):25 Apr 2016
DOI:10.1039/C6SC01055E
The plasmon-induced light concentration (PILC) effect, which has been supposed to be responsible for lots of linear and nonlinear enhanced optical signals such as Raman and high-harmonic generation, is hard to directly observe. Herein, we developed a scattered light based composite-field microscopy imaging (iCFM) system by coupling the oblique and vertical illumination modes, which were adopted in dark- and bright-field microscopy imaging systems, respectively, and through which iCFM system monochromatic background (MCB) images are available, to directly observe the PILC effect in far-field scattering microscopy imaging. Owing to the PILC effect, the scattering signal gain of plasmonic nanoparticles was found to be larger than that of the background, and the imaging visibility of plasmonic nanoparticles was improved by 2.4-fold for silver nanoparticles (AgNPs) and 1.6-fold for gold nanorods (AuNRs). Successful observation of the PILC effect visually together with application in enhanced visibility in cancer cell imaging by this composite illumination system might open an exciting prospect of light scattering microscopy imaging techniques with largely increased visibility.
Co-reporter:Min Lin, Hong Yan Zou, Tong Yang, Ze Xi Liu, Hui Liu and Cheng Zhi Huang
Nanoscale 2016 vol. 8(Issue 5) pp:2999-3007
Publication Date(Web):05 Jan 2016
DOI:10.1039/C5NR08177G
The inner filter effect (IFE), which results from the absorption of the excitation or emission light by absorbers, has been employed as an alternative approach in sensing systems due to its flexibility and simplicity. In this work, highly photoluminescent carbon nanodots (CDs), which were simply prepared through a new one-step microwave synthesis route, were loaded in electrospun nanofibers, and the obtained nanofibers were then successfully applied to develop a fluorescent IFE-based visual sensor for tetracycline hydrochloride (Tc) sensing in milk. This developed visual sensor has high selectivity owing to the requirements of the spectral overlap between the CDs and Tc, showing high promise in sensing chemistry with an efficient response and economic effect.
Co-reporter:Xiao Xi Yang, Chun Mei Li and Cheng Zhi Huang
Nanoscale 2016 vol. 8(Issue 5) pp:3040-3048
Publication Date(Web):06 Jan 2016
DOI:10.1039/C5NR07918G
Interactions between nanoparticles and viruses have attracted increasing attention due to the antiviral activity of nanoparticles and the resulting possibility to be employed as biomedical interventions. In this contribution, we developed a very simple route to prepare uniform and stable silver nanoparticles (AgNPs) with antiviral properties by using curcumin, which is a member of the ginger family isolated from rhizomes of the perennial herb Curcuma longa and has a wide range of biological activities like antioxidant, antifungal, antibacterial and anti-inflammatory effects, and acts as reducing and capping agents in this synthetic route. The tissue culture infectious dose (TCID50) assay showed that the curcumin modified silver nanoparticles (cAgNPs) have a highly efficient inhibition effect against respiratory syncytial virus (RSV) infection, giving a decrease of viral titers about two orders of magnitude at the concentration of cAgNPs under which no toxicity was found to the host cells. Mechanism investigations showed that cAgNPs could prevent RSV from infecting the host cells by inactivating the virus directly, indicating that cAgNPs are a novel promising efficient virucide for RSV.
Co-reporter:Yun Huan Yuan, Ze Xi Liu, Rong Sheng Li, Hong Yan Zou, Min Lin, Hui Liu and Cheng Zhi Huang
Nanoscale 2016 vol. 8(Issue 12) pp:6770-6776
Publication Date(Web):23 Feb 2016
DOI:10.1039/C6NR00402D
Surface states of carbon dots (CDs) are critical to the photoemission properties of CDs. By carefully adjusting the reaction conditions in a hydrothermal synthesis route, we have prepared a series of CDs with excitation-dependent emission (EDE) and excitation-independent emission (EIE) properties by controlling the content of nitrogen elements, confirming that the characteristic optical properties of CDs originate from their energy levels. It has been found that surface-passivation of the as-prepared CDs by nitrogen doping can improve the emission efficiency and be beneficial to EIE features due to the single electron transition resulting from the single functional groups. And the as-prepared CDs can specifically bind with Hg2+ with the emission quenched because of the electron transfer from the LUMO levels of CDs to Hg2+.
Co-reporter:Jun Ma, Yue Liu, Peng Fei Gao, Hong Yan Zou and Cheng Zhi Huang
Nanoscale 2016 vol. 8(Issue 16) pp:8729-8736
Publication Date(Web):11 Mar 2016
DOI:10.1039/C5NR08837B
Low accuracy is a big obstacle in the dark-field microscopy imaging (iDFM) technique in practical applications. In order to reduce the deviations and fluctuations in the observed or snapped scattered light in the iDFM technique caused by unavoidable measurement errors, bare gold nanoparticles (AuNPs) were introduced as an internal reference (IR). The feasibility of using AuNPs as the IR in iDFM in theory was verified. The function of the IR in improving the precision of the acquired data through post data analysis was identified by three kinds of experiments: monitoring the oxidation process of silver nanoparticles (AgNPs) at room temperature, quantifying the level of glucose with AgNPs used as probes and quantifying the change in the light intensity of AuNPs after the plasmon resonance energy transfer (PRET) between AuNPs and tetramethylrhodamine (TAMRA).
Co-reporter:Ze Xi Liu, Zhu Lian Wu, Ming Xuan Gao, Hui Liu and Cheng Zhi Huang
Chemical Communications 2016 vol. 52(Issue 10) pp:2063-2066
Publication Date(Web):08 Dec 2015
DOI:10.1039/C5CC08635C
Photoluminescent carbon dots (CDs), hydrothermally prepared using tannic acid (TA), show visual aggregation induced emission enhancement (AIEE) properties at 455 nm when excited at 350 nm owing to the rotational hindering of the surface groups on CDs such as aromatic rings and phenolic hydroxyl ones, causing exponential decay between the ratio of the photoluminescence intensity in organic solvents to that in water and the permittivity of the solvent, and thus dazzling emissions of the CDs in the presence of solvents with small permittivity, tetrahydrofuran (THF), for instance, could be visually observed.
Co-reporter:Tong Yang, Jun Ma, Shu Jun Zhen, and Cheng Zhi Huang
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 23) pp:14802-14811
Publication Date(Web):May 23, 2016
DOI:10.1021/acsami.6b03720
Surface-enhanced Raman scattering (SERS) has shown high promise in analysis and bioanalysis, wherein noble metal nanoparticles (NMNPs) such as silver nanoparticles were employed as substrates because of their strong localized surface plasmon resonance (LSPR) properties. However, SERS-based pH sensing was restricted because of the aggregation of NMNPs in acidic medium or biosamples with high ionic strength. Herein, by using the electrostatic interaction as a driving force, AgNPs are assembled on the surface of ethylene imine polymer (PEI)/poly(vinyl alcohol) (PVA) electrospun nanofibers, which are then applied as highly sensitive and reproducible SERS substrate with an enhancement factor (EF) of 107–108. When p-aminothiophenol (p-ATP) is used as an indicator with its b2 mode, a good and wide linear response to pH ranging from 2.56 to 11.20 could be available, and the as-prepared nanocomposite fibers then could be fabricated as excellent pH sensors in complicated biological samples such as urine, considering that the pH of urine could reflect the acid–base status of a person. This work not only emerges a cost-effective, direct, and convenient approach to homogeneously decorate AgNPs on the surface of polymer nanofibers but also supplies a route for preparing other noble metal nanofibrous sensing membranes.
Co-reporter:Chun Mei Li, Lei Zhan, Lin Ling Zheng, Yuan Fang Li and Cheng Zhi Huang
Analyst 2016 vol. 141(Issue 10) pp:3020-3026
Publication Date(Web):23 Mar 2016
DOI:10.1039/C6AN00489J
Qualitative and quantitative determination of lysozyme concentrations in urine and serum with high selectivity and sensitivity is important for diagnosing the progression of several diseases. In this report, we devised an improved method for specifically detecting lysozyme by combining magnetic nanoparticles (for separation and enrichment), an aptamer (for selective binding of lysozyme) and strongly scattering silver nanoparticles (AgNPs, for detection by light scattering, but also providing another level of selectivity due to their electrostatic binding with lysozyme). In this system, 0.4–30 nM lysozyme could be simply detected owing to the decreased light scattering of AgNPs in solution after magnetic separation, with a detection limit of 100 pM. In addition, lysozyme was also able to be semi-quantified by using the dark-field light scattering images of AgNPs after enrichment by the MNP–apt–lysozyme complex. Moreover, this design shows great promise for the robust and reliable detection of lysozyme in real samples, with a recovery rate ranging from 98.6% to 101.3% in human serum samples. Therefore, this assay provided robust measurements with good specificity, sensitivity, and tolerance of changes in the sample matrix. We expect that this MNP-based aptasensor may find utility in the accurate diagnosis of lysozyme-related diseases.
Co-reporter:Bin Bin Chen, Ze Xi Liu, Hong Yan Zou and Cheng Zhi Huang
Analyst 2016 vol. 141(Issue 9) pp:2676-2681
Publication Date(Web):23 Feb 2016
DOI:10.1039/C5AN02569A
The detection of nitroaromatic explosives is of great importance owing to their strong explosive power and harmfulness in terms of the environment, homeland security and public safety. Herein, rare earth-doped carbon dots with multifunctional features were firstly prepared by simply keeping the mixture of terbium(III) nitrate pentahydrate and citric acid at 190 °C for 30 min. The as-prepared terbium doped carbon dots (Tb-CDs), through a rapid and simple direct carbonization route, have a size of about 3 nm, and exhibit excitation wavelength dependent emission of blue fluorescence, are stable, and can be applied for the selective and colorimetric detection of 2,4,6-trinitrophenol (TNP) in the range of 500 nM–100 μM with a limit of detection of 200 nM based on the inner filtering effect (IFE) of the excitation and emission bands of Tb-CDs by TNP and the electron transfer (ET) from Tb-CDs to TNP, giving a precise and highly reproducible result for detecting complex water samples.
Co-reporter:Qiang Wang, Wen Long Li, Hong Yan Zou, Hui Liu and Cheng Zhi Huang
New Journal of Chemistry 2016 vol. 40(Issue 7) pp:6315-6324
Publication Date(Web):09 May 2016
DOI:10.1039/C5NJ03379A
Carbon nanotubes (CNTs) are well known as photo-thermal agents for the ablation of tumor cells, but are limited in the application of photo-thermal therapy (PTT) owing to their low molar extinctions. By coupling the photo-thermal effects of CNTs and the intense localized surface plasmon resonance (LSPR) in the near-infrared (NIR) region of Cu2−xSe nanoparticles (NPs), herein we developed a highly efficient PTT nanohybrids agent by in situ growth of Cu2−xSe NPs on the acid-functionalized CNTs at room temperature. The as-prepared Cu2−xSe/CNT nanohybrids have been found to have intense LSPR in the NIR region and good photo-thermal conversion properties. Moreover, possessing good biocompatibility and dispersibility, the nanohybrids could easily be internalized by cancer cells, and show smart photo-thermal performance, properties which were then successfully applied for photo-thermal therapy in vitro, indicating that the Cu2−xSe/CNT nanohybrids could be a potential photo-thermal therapy agent for the ablation of tumor cells.
Co-reporter:Rong Sheng Li, Hai Liu, Bin Bin Chen, Hong Zhi Zhang, Cheng Zhi Huang and Jian Wang
Analytical Methods 2016 vol. 8(Issue 11) pp:2494-2501
Publication Date(Web):18 Feb 2016
DOI:10.1039/C6AY00367B
In this work, a novel method for colorimetric detection of cysteine was proposed based on the inhibition of peroxidase-like behavior of AuNPs. Kiwi juice prepared gold nanoparticles presented strong catalytic activity, which could catalyze H2O2–TMB to generate a blue product, resulting in strong absorption at 650 nm. In HAc–NaAc (pH 4.0) buffer, cysteine induced the aggregation of gold nanoparticles through covalent Au–S bonds and electrostatic as well as hydrogen bonding, leading to the reduction of the catalytic activity of gold nanoparticles with a weakened blue color product and a lower absorbance. Under optimal conditions, the concentrations of cysteine were proportional to the degree of reduced absorbance. This approach offers a new, simple, sensitive and selective assay for cysteine.
Co-reporter:Xue WANG, Kun-Cheng YANG, Zhi-Yuan MAO, Cheng-Zhi HUANG, Jian WANG
Chinese Journal of Analytical Chemistry 2016 Volume 44(Issue 10) pp:1482-1486
Publication Date(Web):October 2016
DOI:10.1016/S1872-2040(16)60960-X
The fluorescence of Rhodamine B (RhB) could be quenched by the manner of photo-induced electron transfer with Cu2-xSe nanoparticles as the energy receptor and RhB as the energy donor. However, L-cysteine (L-Cys) was capable of recovering the fluorescence of Rhodamine B, and the recovered fluorescence intensity was proportional to the concentrations of L-Cys. Based on that, a novel method for detecting L-Cys was established. After mixing L-Cys and RhB pretreated by Cu2-xSe nanoparticles at pH 4.6 and 30 °C for 2 min, a linear relationship was obtained between the fluorescence intensity of RhB at 575 nm and the concentrations of L-Cys in the range of 2.5 × 10−7−1.1 × 10−6 M. This method was used for the determination of L-cys with a detection limit (3σ/k) of 5.5 × 10−8 M. The common amino acids presented little interference for the detection of L-Cys.In this work, a turn on-off fluorescence assay for L-cys was developed based on the energy transfer between Cu2-xSe nanoparticles and thRhodamine B, wherein Cu2-xSe nanoparticles acted as energy receptor to quench Rhodamine B fluorescence, but L-cys was capable of recovering the quenched fluorescence. This method is demonstrated to be rapid and selective.
Co-reporter:Shujun Zhen;Xiaoyan Wan;Linling Zheng;Chunmei Li;Chengzhi Huang
Science Bulletin 2016 Volume 61( Issue 8) pp:639-644
Publication Date(Web):2016 April
DOI:10.1007/s11434-016-1049-3
A novel sensitive semi-quantitative virus detection technique was developed using the respiratory syncytial virus (RSV) as an example, through dark-field light scattering imaging of the surface state of the virus-invaded host cells. In this method, anti-RSV-antibody modified gold nanoparticles (AuNPs) could bind with the invading virus on the cell membrane of the infected host cells through the specific antibody-antigen binding. Then, the host cells could be imaged by the localized surface plasmon resonance light scattering properties of AuNPs under a dark-field light scattering microscopy, which could be further used to semi-quantify the invading virus.本文以呼吸道合胞病毒为例,创建了一种利用暗场显微镜对被病毒侵染的宿主细胞成像, 从而实现半定量检测病毒的新方法。在本方法中,抗呼吸道合胞病毒抗体修饰的金纳米颗粒可以通过抗原-抗体反应结合在宿主细胞膜表面。利用金纳米颗粒的局域表面等离子体性质在暗场显微镜下对宿主细胞成像,进一步实现对侵染病毒的半定量检测。
Co-reporter:Lei Zhan, Shu Jun Zhen, Xiao Yan Wan, Peng Fei Gao, Cheng Zhi Huang
Talanta 2016 Volume 148() pp:308-312
Publication Date(Web):1 February 2016
DOI:10.1016/j.talanta.2015.10.081
•A novel SERS immunoassay based on enzyme reaction was developed.•Enzyme reaction product causes aggregation of AgNPs to produce strong SERS signals.•The minimum detectable concentration of RSV reaches 0.05 pg/mL.Respiratory viruses have become a major global health challenge which would benefit from advances in screening methods for early diagnosis. Respiratory syncytial virus (RSV) is one of the most important pathogen causing severe lower respiratory tract infections. Here we present a novel surface-enhanced Raman scattering (SERS) enzyme-catalyzed immunoassay of RSV by employing peroxidase substrate 3, 3′–5, 5′-tetramethylbenzidine (TMB) as Raman molecule. Horseradish peroxidase (HRP) attached to the detection antibody in a novel sandwich immunoassay catalyzes the oxidation of TMB by H2O2 to give a radical cation (TMB+), which could be easily adsorbed on the negatively charged surface of silver nanoparticles (AgNPs) through electrostatic interaction, inducing the aggregation of AgNPs and thus giving a strong SERS signal. A linear relationship was obtained between the Raman intensity and the amount of RSV in the range from 0.5 to 20 pg/mL, and the minimum detectable concentration of this SERS-based enzyme immunoassay was 0.05 pg/mL, which was 20 times lower than that found in the colorimetric method.A highly sensitive immunoassay of respiratory syncytial virus (RSV) based on surface-enhanced Raman scattering (SERS) has been developed by employing peroxidase substrate 3, 3′–5, 5′-tetramethylbenzidine (TMB) as Raman molecule.
Co-reporter:Jing Han, Hong Yan Zou, Ming Xuan Gao, Cheng Zhi Huang
Talanta 2016 Volume 148() pp:279-284
Publication Date(Web):1 February 2016
DOI:10.1016/j.talanta.2015.10.038
•A new strategy for riboflavin (RF) determination based on fluorescence resonance energy transfer (FRET) was developed.•In this system, graphitic carbon nitride (g-C3N4) nanosheets were employed as the donor and RF acted as the energy acceptor.•This system can be used to quantify RF in complex systems such as milk and drink sensitively.•The novel principle of FRET based on ratiometric sensing strategy can enable an attractive assay system platform for quantifying other analytes of interest.Fluorescence resonance energy transfer (FRET), which occurs between two luminescent chromophores, can greatly improve the selectivity and sensitivity of a fluorescent assay when a ratiometric signaling with the fluorescence enhancement of the acceptor at the expense of the donor is adopted. In this study, a fluorescence ratiometric detection (FRD) of riboflavin (RF) has been made based on FRET, as the strong overlap occurred between the emission spectrum of graphitic carbon nitride (g-C3N4) and absorption spectrum of RF, in which g-C3N4 acts as the energy donor and RF as the energy acceptor. With increasing concentration of RF, the fluorescence intensity of g-C3N4 emission at 444 nm decreased and the fluorescence peak at 523 nm for RF increased regularly, making the fluorescence intensity ratio of 523 nm to 444 nm linearly dependent on the concentration of RF in the range from 0.4 μM to 10 μM, giving a limit of the detection of 170 nM. This method can be used to quantify RF in complex systems such as milk and drink, showing that the novel FRET-based fluorescence ratiometric detection can enable an attractive assay platform for analytes of interest.This study developed an innovative fluorescence ratiometric detection (FRD) of riboflavin (RF) based on fluorescence resonance energy transfer (FRET), in which graphitic carbon nitride (g-C3N4) nanosheet acts as the energy donor and RF as the energy acceptor.Download full-size image
Co-reporter:Jian Wang, Yong Chang, Wen Bi Wu, Pu Zhang, Shao Qing Lie, Cheng Zhi Huang
Talanta 2016 Volume 152() pp:314-320
Publication Date(Web):15 May 2016
DOI:10.1016/j.talanta.2016.01.018
•The fluorescence of AuNCs was quenched by H2O2, which is possibly attributed to the degradation of AuNCs or blockage of the ligand-to-metal nanoparticle core charge transfer by breaking the Au–S bond.•The AuNCs–uricase sensor exhibited high selectivity and visual assay.•The AuNCs–uricase sensor presented great potential for clinical diagnosis.Clinically, the amount of uric acid (UA) in biological fluids is closely related to some diseases such as hyperuricemia and gout, thus it is of great significance to sense UA in clinical samples. In this work, red gold nanoclusters (AuNCs) with relatively high fluorescence quantum yield and strong fluorescence emission were facilely available using bovine serum albumin (BSA) as template. The fluorescence of BSA-protected AuNCs can be sensitively quenched by H2O2, which is further capable of sensing UA through the specific catalytic oxidation with uricase, since it generates stoichiometric quantity of H2O2 by-product. The proposed assay allows for the selective detection of UA in the range of 10–800 μM with a detection limit of 6.6 μM, which is applicable to sense UA in clinical samples with satisfactory results, suggesting its great potential for diagnostic purposes.A highly selective fluorescence-quenching assay for uric acid has been developed through the selective catalytic oxidation with uricase, which is applicable to sense uric acid in clinical samples with satisfactory results, suggesting its great potential for diagnostic purposes.
Co-reporter:Jian Wang;Yuqing Du;Shaoqing Lie;Chengzhi Huang
Science China Chemistry 2016 Volume 59( Issue 11) pp:1513-1518
Publication Date(Web):2016 November
DOI:10.1007/s11426-015-0529-8
Assembling and ordering nanomaterials into desirable patterns are considerably significant, since the properties of nanomaterials depend not only on the size and shape, but also on the spatial arrangement among the collective building blocks. In this work, the DNA self-assembly technology of hybridization chain reaction (HCR) provided a convenient method to yield long double-strand DNA (dsDNA) to install gold nanoparticles (AuNPs) into one dimensional assembly along the skeleton of dsDNA. Interestingly, the tunable length of AuNPs assemblies along dsDNA chain could be achieved by adjusting the reaction time of HCR, which is based on the formation of covalent bond between Au and the -SH group of DNA. Compared with weak light scattering of single AuNP, these AuNPs assemblies could be clearly imaged under the dark field microscopy, indicating that the light scattering was greatly improved after assembling.
Co-reporter:Shujun Zhen;Tong Wu;Xin Huang;Yuanfang Li;Chengzhi Huang
Science China Chemistry 2016 Volume 59( Issue 8) pp:1045-1050
Publication Date(Web):2016 August
DOI:10.1007/s11426-015-0482-5
We report a new strategy to prepare gold nanoflowers (AuNFs) using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering (SERS) substrates, showing strong signal enhancement. We further found that iodide ions (I–) could selectively induce the morphological transformation of AuNFs to spheres, resulting in a blue-shift of the localized surface plasmon resonance (LSPR) bands, a color change of the AuNFs solution from blue to red, and decreased SERS activity. This behavior allows the AuNFs to be used in the determination of I–.
Co-reporter:Yuting Mao;Hongyan Zou;Qiang Wang;Chengzhi Huang
Science China Chemistry 2016 Volume 59( Issue 7) pp:903-909
Publication Date(Web):2016 July
DOI:10.1007/s11426-016-5600-5
A simple green hydrothermal template-free method was developed to prepare single-crystalline superstructures of fern-wort-like copper selenide (CuSe) in large-scale by using polyvinylpyrrolidone (PVP) as both reductant and surfactant for the first time. Time-dependent morphologic evolution was made in order to explore the formation mechanism of the as-prepared product. The copper selenides with different morphologies, phases and structural forms could be prepared by varying the synthesis parameters, such as precursor molar ratios, precursor combinations, and the molecular weight of PVP. The fernwort-like superstructures of CuSe show excellent Fenton-like catalytic activities in degrading malachite green (MG) and rhodamine B (RhB). These catalysts play an important role in the degradation process of MG and RhB solution with the aid of H2O2 which can yield highly reactive hydroxyl radicals (HO·). Besides, the as-prepared CuSe catalyst is stable and reusable, thus it could be applied to the treatment of the dye contaminated waste water.
Co-reporter:Ting Ting Wang, Jing Lan, Yue Zhang, Zhu Lian Wu, Chun Mei Li, Jian Wang and Cheng Zhi Huang
Journal of Materials Chemistry A 2015 vol. 3(Issue 30) pp:6377-6384
Publication Date(Web):30 Jun 2015
DOI:10.1039/C5TB00824G
Synergistic therapy has become a potential treatment in the battle against disease. In this work, we developed a novel versatile folate targeted system for cancer cells with the combination of chemotherapy and phototherapy by using mesoporous silica nanoparticles (MSNs) as a drug loading carrier, in which reduced graphene oxide (rGO) gated the MSNs by pH responsive detachment. That is, rGO herein acts not only for gating control of the drug release but also for near-infrared photothermal therapy. With this drug loading system, high photothermal conversion efficiency and excellent doxorubicin (DOX) loading capacity have been achieved, making the DOX loaded MSN@rGO-FA (DOX@MSN@rGO-FA) nanocomposites able to kill 68% of HEp-2 cells in synergistic therapy, as compared with 54% in photothermal therapy and 33% in chemotherapy, respectively, illustrating that a synergistic therapy strategy using this newly developed versatile drug loading system is much more efficient as evaluated in vitro.
Co-reporter:Yi Wang, Hong Yan Zou and Cheng Zhi Huang
Nanoscale 2015 vol. 7(Issue 37) pp:15209-15213
Publication Date(Web):17 Aug 2015
DOI:10.1039/C5NR04234H
A low-cost and easily-conducted light-scattering dark-field microscopy imaging (iDFM) technique for real-time and in situ monitoring of the oxidative etching on a single Ag nanocube was presented by using an ordinary dark-field microscopy system, which provides an alternative approach to study the behaviors of metal nanoparticles in chemical reactions and biological processes at the single nanoparticle level.
Co-reporter:Yun Huan Yuan, Rong Sheng Li, Qiang Wang, Zhu Lian Wu, Jian Wang, Hui Liu and Cheng Zhi Huang
Nanoscale 2015 vol. 7(Issue 40) pp:16841-16847
Publication Date(Web):10 Sep 2015
DOI:10.1039/C5NR05326A
Carbon dots doped with germanium (GeCDs) were firstly prepared by a new simple 15 min carbonation synthesis route, exhibiting excitation-independent photoluminescence (PL), which could avoid autofluorescence in bioimaging applications. The as-prepared GeCDs have low cell toxicity, good biocompatibility, high intracellular delivery efficiency, stability and could be applied for detection of mercury(II) ions with excellent selectivity in complicated medium. It is to be noted that the as-prepared GeCDs used as a new type of probe for visualization of dynamic invasions of mercury(II) ions into Hep-2 cells display greatly different properties from most of the previously reported CDs which are regularly responsive to iron ions. All the results suggest that the GeCDs can be employed for visualization and monitoring of the significant physiological changes of living cells induced by Hg2+.
Co-reporter:Gang Lei, Peng Fei Gao, Hui Liu and Cheng Zhi Huang
Nanoscale 2015 vol. 7(Issue 48) pp:20709-20716
Publication Date(Web):11 Nov 2015
DOI:10.1039/C5NR05838D
Single nanoparticle analysis (SNA) technique with the aid of a dark-field microscopic imaging (iDFM) technique has attracted wide attention owing to its high sensitivity. Considering that the degradation of pesticides can bring about serious problems in food and the environment, and that the real-time monitoring of the dynamic degradation process of pesticides can help understand and define their degradation mechanisms, herein we real-time monitored the decomposition dynamics of sodium dimethyldithiocarbamate (NaDDC) under neutral and alkaline conditions by imaging single silver nanoparticles (AgNPs) under a dark-field microscope (DFM); the localized surface plasmon resonance (LSPR) scattering signals were measured at a single nanoparticle level. As a result, the chemical mechanism of the degradation of NaDDC under neutral and alkaline conditions was proposed, and the inhibition effects of metal ions including Zn(II) and Cu(II) were investigated in order to understand the decomposition process in different environments. It was found that Cu(II) forms the most stable complex with NaDDC with a stoichiometric ratio of 1:2, which greatly reduces the toxicity.
Co-reporter:Tong Yang, Hong Yan Zou, and Cheng Zhi Huang
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 28) pp:15447
Publication Date(Web):June 26, 2015
DOI:10.1021/acsami.5b03645
A new heterogeneous catalytic composite composed of nonstoichiometric Cu2–xSe nanoparticles (NPs) with high copper deficiency and graphene oxide (GO) is prepared by coembedding in electrospun nanofibers of a poly(vinylpyrrolidone) (PVP) support, wherein GO in the nanofibers is converted into reduced GO (rGO) via heat treatment. The as-prepared composite Cu2–xSe/rGO/PVP nanofibers have demonstrated superior catalytic activity toward the reduction of a refractory organic compound by taking 4-nitrophenol (4-NP) as an example. In the presence of NaBH4, the Cu2–xSe/rGO/PVP nanofibers display a synergetic effect between Cu2–xSe and rGO in PVP nanofibers compared to their independent components or corresponding nanofibers. Furthermore, the Cu2–xSe/rGO/PVP nanofibers exhibit a favorable water-stable property via heat treatment to solidify the hydrophilic PVP matrix, which makes the composite display good reusability, stability in aqueous solution, and separability from a water medium. This work not only presents a direct, convenient, and effective approach to doping semiconductor nanomaterials into polymer nanofibers but also provides fundamental routes for further investigations about the synergetic effect between different materials based on the platform of electrospun nanofibers.Keywords: 4-nitrophenol; catalytic reduction; Cu2−xSe and rGO; electrospun nanofibers; synergetic effect;
Co-reporter:Tong Yang, Hui Yang, Shu Jun Zhen, and Cheng Zhi Huang
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 3) pp:1586
Publication Date(Web):December 29, 2014
DOI:10.1021/am507010q
Reproducibility in surface enhanced Raman scattering (SERS) measurements is a challenge. This work developed a facile way to make highly dispersed uniform silver nanoparticles (AgNPs) loaded in the agar/polyacrylonitrile (PAN) nanofibers by the coupling the electrospinning technology from metal complex-containing polymer solution and in situ photoreductive technique. Agar, as hydrophilic component, was introduced into the electrospinning solution considering that its abundant hydroxyl group sites could greatly improve the contents of silver ions in the polymers because of the rich silver ion chelated with the hydroxyl group, whereas hydrophilic agar was integrated with hydrophobic PAN by −OH···N≡C– hydrogen bonds as a bridge. Meanwhile, the in situ photoreductive reaction was made under different light irradiations such as desk lamp, 365 nm UV-lamp, and 254 nm UV-lamp. High yield of stable AgNPs with highly uniform and dispersion are available in the agar/PAN nanofibers after the in situ photoreductive reaction, supplying the possibility of reproducible SERS signals. To identify that concept of proof, a facile approach for the determination of malachite green (MG) in three environmental practical samples was demonstrated by using the composite nanofibrous material irradiated by 365 nm UV-lamp, giving the minimum detection concentration of MG as low as 0.1 μmol/L with a good linear response ranging from 0.1–100 μmol/L (R2 = 0.9960).Keywords: agar; electrospinning; hydrogen bonds; in situ photoreduction; reproducible SERS substrates
Co-reporter:Zhongwei Jiang, Pengfei Gao, Lin Yang, Chengzhi Huang, and Yuanfang Li
Analytical Chemistry 2015 Volume 87(Issue 24) pp:12177
Publication Date(Web):November 17, 2015
DOI:10.1021/acs.analchem.5b03058
Surface-enhanced Raman scattering (SERS) signals are intensively dominated by the Raman hot spots and distance between analyte molecules and metallic nanostructures. Herein, an efficient SERS substrate was developed by in situ synthesis of silver nanoparticles (AgNPs) on the surface of MIL-101 (Fe), a typical metal–organic framework (MOF). The as-prepared SERS substrate combines the numerous Raman hot spots between the high-density Ag NPs and the excellent adsorption performance of MOFs, making it an excellent SERS substrate for highly sensitive SERS detection by effectively concentrating analytes in close proximity to the Raman hot spots domains between the adjacent AgNPs. The resulting hybrid material was used for ultrasensitive SERS detection of dopamine based on the peroxidase-like activity of MIL-101 (Fe) by utilizing the enzyme-linked immunosorbent assay (ELISA) colorimetric substrate, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) as a SERS marker. This new developed method showed good linearity in the range from 1.054 pM to 210.8 nM for dopamine with the correlation coefficient of 0.992, detection limit of approximately 0.32 pM [signal-to-noise ratio (S/N) = 3], and acceptable recoveries ranging from 99.8% to 108.0% in human urine. These results predict that the proposed SERS system may open up a new opportunity for chemical and biological assay applications.
Co-reporter:Shu Jun Zhen, Yan Yu, Chun Mei Li and Cheng Zhi Huang
Analyst 2015 vol. 140(Issue 1) pp:353-357
Publication Date(Web):21 Oct 2014
DOI:10.1039/C4AN01433B
Fluorescence anisotropy (FA) has attracted considerable attention, but it has been rarely applied for the detection of small molecules and metal ions because they are too small to induce evident FA changes. Although some mass amplifying strategies have been developed, the recognition probes need to be covalently modified with the fluorescent dyes, which is complex and expensive. To overcome this limitation, a new simple, label-free and cost-effective method for the sensitive detection of potassium ion (K+), by using graphene oxide (GO) as FA enhancer, a G-rich single stranded DNA (ssDNA) as recognition probe and acridine orange (AO) as FA reporting fluorophore, was established in this paper. In the absence of K+, both ssDNA and AO are adsorbed on the surface of GO, and the FA of AO is enhanced greatly because the rotation of AO is coupled with the entire formation. After the addition of K+, the ssDNA self-associates into the G-quadruplex structure. Then, AO can bind with the formed G-quadruplex strongly, keeping away from the surface of GO, and the FA of AO decreases significantly because of the relatively small size of the complex of AO and G-quadruplex. Thus K+ can be detected sensitively in the range of 10 μM–2 mM based on the evidently decreased FA. This method is a further improvement of the previous reported mass amplifying strategies because it does not require any covalent labelling of the recognition probe, and it can be potentially applied for detection of a variety of other targets.
Co-reporter:Qun Wei Shu, Jing Lan, Ming Xuan Gao, Jian Wang and Cheng Zhi Huang
CrystEngComm 2015 vol. 17(Issue 6) pp:1374-1380
Publication Date(Web):15 Dec 2014
DOI:10.1039/C4CE02120G
3-D CuS materials have attracted attention due to their unique catalytic properties. These materials are generally synthesized by the template method; however, this process is time-consuming, complex, and results in low catalytic activity. In this paper, we describe a new method for the synthesis of monodisperse and highly homogeneous CuS caved superstructures with a variety of shapes and sizes. Our synthesis was accomplished in 2.5 h by a simple direct solvothermal reaction of CuSO4 with sulfur powder under normal pressure, and achieved by the reduction of acetaldehyde produced from ethylene glycol (EG) during the heating process. We show that the size and morphology of CuS products can be tuned by adjusting the molar ratios of reactants, reaction temperature and preheating temperature. The CuS caved superstructures prepared were highly catalytic, as shown by examining the degradation of methylene blue (MB) in the absence of light through the oxidation of hydroxide radicals produced from H2O2 in the catalytic reaction. This shows that the CuS catalyst prepared by our novel method has efficient catalytic activity, making it a cost-effective and convenient method for the treatment of dye-contaminated wastewater.
Co-reporter:Hong Wang, Dong Mei Wang and Cheng Zhi Huang
Analyst 2015 vol. 140(Issue 16) pp:5742-5747
Publication Date(Web):29 Jun 2015
DOI:10.1039/C5AN00884K
A simple and highly sensitive method for detecting lead ion (Pb2+) in biosamples was developed based on its displacement of potassium in G-Quadruplex DNAzyme, which can catalyze the luminol–H2O2 chemiluminescence (CL) reaction. By introducing a G-rich DNA sequence, PS2.M, which can fold into a G-quadruplex when binding with hemin in the presence of K+ and act as a superior horseradish peroxidase (HRP) mimicking-enzyme, we found this DNAzyme can effectively catalyze the H2O2-mediated oxidation of luminol, resulting in strong CL emission. The K+-stabilized G-quadruplex, upon the addition of Pb2+, is transformed into a Pb2+-stabilized G-quadruplex with higher stability but poor DNAzyme activity, sharply decreasing the CL readout signal. With this, a simple and sensitive detection method for Pb2+ in biosamples such as human hairs was developed with a linear range of 0.4–10 nM Pb2+ and a limit of detection (3σ) of 0.06 nM. Owing to the introduction of G-quadruplex DNAzyme, which was employed not only as a sensing unit but also as a catalyst in the chemiluminescent assay, this method holds great potential for clinical plumbism diagnosis by testing hair.
Co-reporter:Hong Yan Zou, Peng Fei Gao, Ming Xuan Gao and Cheng Zhi Huang
Analyst 2015 vol. 140(Issue 12) pp:4121-4129
Publication Date(Web):25 Mar 2015
DOI:10.1039/C5AN00221D
Full understanding and easy construction of specific biosensing principles is necessary for disease diagnostics and therapeutics in the hope of creating new types of biosensors. Herein, we developed a new conceptual nanobiosensing platform by coupling nanometal surface energy transfer (NSET) and photo-induced electron transfer (PET) with polydopamine-embedded Cu2−xSe nanoparticles (Cu2−xSeNPs@pDA) and DNA-conjugated fluorescent organic dyes. The new prepared Cu2−xSeNPs@pDA has intense and broad localized surface plasmon resonance (LSPR) absorption over UV to near infrared (NIR) wavelengths, with different affinities toward ssDNA versus dsDNA. It also exhibits a high multiplexed fluorescence quenching ability, and thus can act as an acceptor in the energy transfer and electron transfer interactions between Cu2−xSeNPs@pDA and fluorescent organic dyes. As a proof of concept, a new biosensing platform has been successfully developed to target biomacromolecules such as DNA and proteins, in which the NSET and PET interactions between Cu2−xSeNPs@pDA and three different DNA-conjugated fluorescent dyes have been identified using steady-state and time-resolved fluorescence. A simple mathematical model was further applied to simulate the respective contributions of the coexisting NSET and PET to the total quenching observed for each DNA-conjugated dye in this sensing system. This study highlights the importance of understanding the mechanistic details of NSET and PET coupling processes, and the disclosed coupling mechanism of NSET and PET (NSET©PET) in the systems of Cu2−xSeNPs@pDA with wide wavelength range dyes provides new opportunities for sensitive biosensing applications.
Co-reporter:Jian Wang, Yong Chang, Pu Zhang, Shao Qing Lie, Peng Fei Gao and Cheng Zhi Huang
Analyst 2015 vol. 140(Issue 24) pp:8194-8200
Publication Date(Web):30 Oct 2015
DOI:10.1039/C5AN01975C
It is of great significance to sense clioquinol (CQ) in a simple and fast way because of its potential application in the treatment of neurodegenerative diseases. In this contribution, we proposed a Cu2+-mediated fluorescence switchable strategy to detect CQ by taking bovine serum albumin (BSA) protected gold nanoclusters (AuNCs) as probes. It was found that the strong red fluorescence of BSA-protected AuNCs at 610 nm could be effectively quenched by Cu2+ (off state) and reversibly recovered by CQ (on state) owing to the specific coordination of CQ and Cu2+. Under the optimal conditions, there was a good linear relationship between the off–on efficiency (Eoff–on) and the amount of CQ in the range of 1–12 μM (R2 = 0.9902), with a detection limit of 0.63 μM (3σ). The “turn off–on” mode and the fast and unique complexation of CQ and Cu2+ endow AuNCs with high specificity for CQ sensing. The proposed strategy is label-free, fast and selective, which is applicable to the analysis of CQ in cream with satisfactory results.
Co-reporter:Jing Han, Hong Yan Zou, Ze Xi Liu, Tong Yang, Ming Xuan Gao and Cheng Zhi Huang
New Journal of Chemistry 2015 vol. 39(Issue 8) pp:6186-6192
Publication Date(Web):27 May 2015
DOI:10.1039/C5NJ01010A
Photocatalytic semiconductors have attracted considerable attention due to their applications in the degradation of organic pollutants. However, the low solar-light harvesting and high electron–hole recombination rate limit the efficiency of photocatalysts. The newly developed localized surface plasmon resonance (LSPR) can offer a new opportunity to overcome the limited efficiency to some extent. In this study, heterojunctions (Cu2−xSe–g-C3N4) incorporating plasmonic semiconductor Cu2−xSe with graphitic carbon nitride (g-C3N4) are proposed as visible light photocatalysts. Their photocatalytic performance is tested and proven via the degradation of methyl blue (MB) in an aqueous solution. When the mass percentage composition of Cu2−xSe reached 60%, the as-prepared composite exhibited the highest photocatalytic activity, which was almost 6.1 and 2.8 times as high as that of individual Cu2−xSe and g-C3N4, respectively. The remarkable photocatalytic efficiency of such Cu2−xSe–g-C3N4 heterojunctions under visible light illumination due to both plasmonic enhancement of the catalyst and synergetic effect of the co-catalyst is shown. This work can provide a new methodology to develop stable and highly efficient heterojunction photocatalysts.
Co-reporter:Lin Zhong, Tong Yang, Jian Wang and Cheng Zhi Huang
New Journal of Chemistry 2015 vol. 39(Issue 12) pp:9518-9524
Publication Date(Web):23 Sep 2015
DOI:10.1039/C5NJ01519G
The catalysis of nanomaterials is interesting and attractive. Herein, electrospinning was employed to afford poly(methyl acrylate) (PMAA)–poly(vinyl pyrrolidone) (PVP) electrospun nanofibers. Next, in situ photosynthesis resulted in the formation of a uniform assembly of silver nanoparticles (AgNPs) over the electrospun fibers, generating AgNPs–PMAA–PVP electrospun nanofibers. The as-formed AgNPs–PMAA–PVP electrospun nanofibers were utilized for investigating the catalytic reduction of 4-nitrophenol (4-NP) in the presence of NaBH4. For the in situ synthesis, the available light sources used included sunlight, table lamps, and 365 nm UV lamps. The results showed that the AgNPs–PMAA–PVP electrospun nanofibers could catalyze the reduction of 4-NP in the presence of NaBH4, generating 4-aminophenol (4-AP), therefore reducing the toxicity of 4-NP. After the use of the AgNPs–PMAA–PVP electrospun nanofibers for up to 4 cycles, the catalytic efficiency remained as high as 90%, suggesting that the noble metal/polymeric electrospun nanofibrous catalyst is highly effective and reusable.
Co-reporter:Wen Long Li, Hong Yan Zou, Jing Lan, Qiang Wang, Yuan Fang Li and Cheng Zhi Huang
RSC Advances 2015 vol. 5(Issue 111) pp:91206-91212
Publication Date(Web):19 Oct 2015
DOI:10.1039/C5RA12019E
Hollow nanostructures have been diversely applied in many fields and efforts have been made to develop their various synthesis methodologies. Herein, homogeneous hollow Cu2−xSeyS1−y/reduced graphene oxide (rGO) nanocomposites were prepared for the first time via a facile and green aqueous chemical approach using H2S gas bubble templates as soft templates at room temperature. It is found that 2D hexagonal Cu2−xSeyS1−y nanosheets assemble around the gas–liquid interface of H2S bubbles to form hollow nanospheres on the rGO sheets, wherein rGO sheets as molecular templates play a critical role in maintaining the structural integrity of single-crystal hollow Cu2−xSeyS1−y nanospheres. Increasing the S content in the precursors, i.e., increasing the amount of H2S bubbles, both the diameter and chalcogen composition (S/Se molar ratio) of hollow Cu2−xSeyS1−y/rGO nanocomposites gradually increase. The near-infrared (NIR) localized surface plasmon resonance (LSPR) in Cu2−xSeyS1−y/rGO nanocomposites, arising from the free carriers (holes) in Cu2−xSeyS1−y, gets red shifts with increasing the S content, due to the higher carrier mass and assembly degree of Cu2−xSeyS1−y.
Co-reporter:Qun Wei Shu, Chun Mei Li, Peng Fei Gao, Ming Xuan Gao and Cheng Zhi Huang
RSC Advances 2015 vol. 5(Issue 23) pp:17458-17465
Publication Date(Web):20 Jan 2015
DOI:10.1039/C4RA14609C
CuS materials with peroxidase activity have been prepared but greatly limited by the large dosage and low peroxidase activity. In this paper, porous hollow CuS nanospheres with a variety of sizes were fabricated by one-pot method based on a facile template-assisted hydrothermal approach. The size of the porous hollow CuS nanospheres could be simply tuned by adjusting the molar ratios of reactants, the reaction temperature, and time. The as-prepared porous hollow CuS nanospheres were demonstrated to exhibit more prominent intrinsic peroxidase-like activity using TMB as a peroxidase substrate in the presence of hydrogen peroxide (H2O2). This is a significant comparison to previous reports, demonstrating that the new developed synthetic porous hollow CuS nanospheres can be a new kind of candidate for peroxidase mimics, and the nanospheres are promising for applications in biosensors, environmental monitoring, and so on.
Co-reporter:Hong Yan Zou, Jing Lan and Cheng Zhi Huang
RSC Advances 2015 vol. 5(Issue 69) pp:55832-55838
Publication Date(Web):03 Jun 2015
DOI:10.1039/C5RA06240C
A simple one-pot synthesis method for small copper nanocrystals (CuNCs) was developed by employing dopamine as a reducing and capping reagent. The as-prepared CuNCs exhibited a fluorescence emission at 390 nm, good peroxidase-mimicking catalytic property, and excellent antibacterial activities against Gram-positive Staphylococcus aureus. Based on the fluorescence and peroxidase-mimicking catalytic features, sensing for ferric ions (Fe3+) was made because Fe3+ ions have specific interactions with the catechol groups on the surface of CuNCs with the limits of detection of 1.2 μM and 4.2 μM, respectively, which were much lower than the maximum level (5.4 μM) of Fe3+ permitted in drinking water by the US Environmental Protection Agency. For the antibacterial activities, a minimum inhibitory concentration of 158 μg mL−1 was found which was because of the generation of reactive oxygen species.
Co-reporter:Li Qiang Chen, Li Fang, Jian Ling, Cheng Zhi Ding, Bin Kang, and Cheng Zhi Huang
Chemical Research in Toxicology 2015 Volume 28(Issue 3) pp:501
Publication Date(Web):January 20, 2015
DOI:10.1021/tx500479m
Silver nanoparticles (AgNPs) are increasingly being used as antimicrobial agents and drug carriers in biomedical fields. However, toxicological information on their effects on red blood cells (RBCs) and the mechanisms involved remain sparse. In this article, we examined the size dependent nanotoxicity of AgNPs using three different characteristic sizes of 15 nm (AgNPs15), 50 nm (AgNPs50), and 100 nm (AgNPs100) against fish RBCs. Optical microscopy and transmission electron microscopy observations showed that AgNPs exhibited a size effect on their adsorption and uptake by RBCs. The middle sized AgNPs50, compared with the smaller or bigger ones, showed the highest level of adsorption and uptake by the RBCs, suggesting an optimal size of ∼50 nm for passive uptake by RBCs. The toxic effects determined based on the hemolysis, membrane injury, lipid peroxidation, and antioxidant enzyme production were fairly size and dose dependent. In particular, the smallest sized AgNPs15 displayed a greater ability to induce hemolysis and membrane damage than AgNPs50 and AgNPs100. Such cytotoxicity induced by AgNPs should be attributed to the direct interaction of the nanoparticle with the RBCs, resulting in the production of oxidative stress, membrane injury, and subsequently hemolysis. Overall, the results suggest that particle size is a critical factor influencing the interaction between AgNPs and the RBCs.
Co-reporter:Wei Wang, Lei Zhan, Yu Qing Du, Fei Leng and Cheng Zhi Huang
Analytical Methods 2015 vol. 7(Issue 2) pp:638-642
Publication Date(Web):24 Nov 2014
DOI:10.1039/C4AY02231A
A novel and selective spectrofluorometric method for pyrophosphate (PPi) assay in aqueous solution was developed in this contribution on the basis of the enhanced fluorescence intensity of trypsin-stabilized copper clusters (CuNCs). Mechanism investigation showed that PPi can make the CuNCs dispersed, concomitantly resulting in the improved quantum yield and the enhanced fluorescence emission of the CuNCs. A good linear relationship in the range of 78 μM–20 mM was achieved between the enhanced fluorescence intensity of the CuNCs at 455 nm and the logarithm of PPi concentration with the detection limit (3σ) of 101 nM. By this approach, we can achieve simple, fast and inexpensive detection of PPi.
Co-reporter:Pu Zhang, Jing Lan, Yi Wang, Zu Hong Xiong, Cheng Zhi Huang
Biomaterials 2015 36() pp: 26-32
Publication Date(Web):
DOI:10.1016/j.biomaterials.2014.08.026
Co-reporter:Jing Lan, Hongyan Zou, Zexi Liu, Mingxuan Gao, Binbin Chen, Yuanfang Li, Chengzhi Huang
Talanta 2015 Volume 143() pp:469-473
Publication Date(Web):1 October 2015
DOI:10.1016/j.talanta.2015.05.042
•Gelatin was firstly used as protective and reducing agent to prepare Ag nanoclusters.•The preparation of Ag nanoclusters could be completed within 4 h at room temperature.•A temperature sensor was developed with gelatin-stabilized Ag nanoclusters.A visual physiological temperature sensor was successfully developed with newly hydrothermally prepared fluorescent silver nanoclusters (AgNCs) at room temperature using gelatin as the protective and reducing agent. The as-prepared gelatin-stabilized AgNCs was water-soluble, uniform and exhibited a narrow distribution with an average size of 1.16 nm, showing a maximum emission band at 552 nm (2.45 eV) when excited at 445 nm (2.79 eV). The large Stokes shift of 110 nm of the gelatin-stabilized AgNCs makes it actually applicable with very low background and light scattering interferences. It was found that the as-prepared gelatin-stabilized AgNCs is temperature-sensitive over the range from 5 °C to 45 °C, and thus a visual physiological temperature sensor could be developed with the gelatin–AgNCs as under the irradiation of visible light.A direct synthesis strategy of water-soluble and fluorescent Ag nanoclusters (AgNCs), using gelatin as protective and reducing agent, has been established in this report. The AgNCs were successfully prepared within 4 h at room temperature. Notably, the gelatin–AgNCs were further applied to be a reversible and sensitive temperature sensor.
Co-reporter:RUI TIAN;GANG YANG;XINMIN LIU;CHENGZHI HUANG
Journal of Chemical Sciences 2015 Volume 127( Issue 6) pp:1083-1089
Publication Date(Web):2015 June
DOI:10.1007/s12039-015-0872-4
Hofmeister (Specific ion) effects have been considered as important to chemical science as Mendel’s work was to genetics. In this work, the aggregation kinetics of montmorillonite colloids in H+, Ag+, NH\(_{4}^{+}\), K+ and Na+ solutions were measured in situ, detecting the unusual kinetics and ion specificity for H+. Activation energies that can quantitatively estimate the underlying specific ion effects change in the order of H+ < Ag+ < NH\(_{4}^{+}<\) K+ < Na+. Meanwhile, it was found that although the aggregation of montmorillonite colloids with lower particle densities results in higher activation energies, Hofmeister series will not be affected. It was sufficiently testified that interaction energies of colloidal particles with adsorbed ions show fine correlation with activation energies for colloidal aggregation, and larger interaction energy corresponds to lower activation energy. An attempt was made to quantitatively estimate the ion specificity for H+, and it was substantialized that the unusual ion specificity of H+ is caused by steric effect.
Co-reporter:Ping Ping Hu, Hui Liu, Lei Zhan, Lin Ling Zheng, Cheng Zhi Huang
Talanta 2015 Volume 139() pp:35-39
Publication Date(Web):1 July 2015
DOI:10.1016/j.talanta.2014.12.050
•Coomassie brilliant dye was employed as Raman reporter and utilized to label the target protein.•Dual-aptamer was addressed, leading to high specificity towards PrP.•Silica shell of the nanoparticles served as versatile substrate for apamter immobilization.•The ensemble of Ag@Si NPs was utilized as the SERS substrate.Surface-enhanced Raman scattering (SERS) spectra, which can provide large information about trace amount of chemical and biological species have been widely performed as a well-established tool in complex biological system. In this work, coomassie brilliant blue (R-250) with high affinity to proteins and high Raman activity was employed as a Raman reporter to probe prion protein (PrP) through a dual-aptamer mechanism, and thus an original strategy for PrP determination was proposed, which showed great potential to turn on the SERS response through specific recognition of anti-prion aptamers towards the target protein. Aptamers (Apt1 and Apt 2) recognizing distinct epitopes of PrP with high affinity were first conjugated to Ag@Si NPs, and Ag@Si-PrP/R-250-Ag@Si conjugates were obtained in the presence of PrP/R-250, inducing dramatically enhanced Raman signal. SERS responses enhanced with increasing amount of PrP and a linear equation of ISERS=6729.7+3091.2 cPrP was obtained in the range of 3.0–12.0×10−9 M with the determination coefficient of 0.988. The proposed strategy is simple, rapid, and high specificity to probe protein–aptamer recognition in the solution.Coomassie Brilliant Blue R-250 was successfully applied as a new Surface-enhanced Raman scattering reporter for protein labeling through a dual-aptamer mechanism, and an original strategy for PrP determination was proposed, which is simple, rapid, and high specific.
Co-reporter:Jing Lan, Chunfang Liu, Mingxuan Gao, Chengzhi Huang
Talanta 2015 Volume 144() pp:93-97
Publication Date(Web):1 November 2015
DOI:10.1016/j.talanta.2015.05.071
•A facile solid-state synthesis (SSS) approach was used to prepare fluorescent CDs.•The surface carboxylation of CDs was achieved through the SSS approach.•The as-prepared CDs were used for intracellular imaging of Fe3+.In order to achieve the simple, easily repeated, and large scale preparation of fluorescent CDs, a new solid-state synthesis (SSS) approach was developed by calcining the mixture of fullerenes (C60) and solid sodium hydroxide. The cage of fullerenes could be opened and the hydroxyl and carboxyl were successfully introduced in the presence of sodium hydroxide under high temperature. The as-prepared surface carboxylated CDs possess many good properties, such as high water solubility, good photostability, salt tolerance, and nontoxicity. Especially, the fluorescence of CDs could be highly quenched by Fe3+ because of the strong interaction of hydroxyl or carboxyl on the as-obtained CDs with Fe3+, which realized a sensitive detection of Fe3+ in the linear range of 0.02–0.6 μmol/L. What is more, we further applied the obtained CDs into the intracellular imaging of Fe3+.By calcining the mixture of fullerenes (C60) and solid sodium hydroxide, surface carboxylated CDs were prepared, which possess the properties of high water solubility, good photostability, salt tolerance, nontoxicity, and could be highly selectively quenched by Fe3+ because of the strong interaction of hydroxyl or carboxyl on the as-obtained CDs with Fe3+, realizing the intracellular imaging of Fe3+.
Co-reporter:Chunmei Li;Tao Chen;Ismail Ocsoy;Guizhi Zhu;Emir Yasun;Mingxu You;Cuichen Wu;Jing Zheng;Erqun Song;Weihong Tan
Advanced Functional Materials 2014 Volume 24( Issue 12) pp:1772-1780
Publication Date(Web):
DOI:10.1002/adfm.201301659
The development of nanomaterials that combine diagnostic and therapeutic functions within a single nanoplatform is extremely important for molecular medicine. Molecular imaging with simultaneous diagnosis and therapy will provide the multimodality needed for accurate diagnosis and targeted therapy. Here, gold-coated iron oxide (Fe3O4@Au) nanoroses with five distinct functions are demonstrated, integrating aptamer-based targeting, magnetic resonance imaging (MRI), optical imaging, photothermal therapy. and chemotherapy into one single probe. The inner Fe3O4 core functions as an MRI agent, while the photothermal effect is achieved through near-infrared absorption by the gold shell, causing a rapid rise in temperature and also resulting in a facilitated release of the anticancer drug doxorubicin carried by the nanoroses. Where the doxorubicin is released, it is monitored by its fluorescence. Aptamers immobilized on the surfaces of the nanoroses enable efficient and selective drug delivery, imaging, and photothermal effect with high specificity. The five-function-embedded nanoroses show great advantages in multimodality.
Co-reporter:Pu Zhang, Xiao Xi Yang, Yi Wang, Ning Wei Zhao, Zu Hong Xiong and Cheng Zhi Huang
Nanoscale 2014 vol. 6(Issue 4) pp:2261-2269
Publication Date(Web):29 Nov 2013
DOI:10.1039/C3NR05269A
Rapid synthesis of protein-stabilized Au20 nanoclusters (Au20NCs) with high fluorescence quantum yield (QY) up to ∼15% is successfully achieved by manipulating the reaction kinetics. The as-obtained Au20NCs, identified by mass spectrometry, have an average size of 2.6 nm, with strong fluorescence emission at 620 nm (2.00 eV) upon excitation at either 370 nm (3.35 eV) or 470 nm (2.64 eV). The advantages of the as-obtained Au20NCs, including small sizes, high fluorescence QY, excellent photostability, non-toxicity, and good stability in biological media, make them ideal candidates as good luminescent probes for optical imaging in vitro and in vivo. Our results demonstrate that the uptake of Au20NCs by both cancer cells and tumor-bearing nude mice can be improved by receptor-mediated internalization, compared with that by passive targeting. Because of their selective accumulation at the tumor sites, the Au20NC probes can be used as potential indicators for cancer diagnosis. This work not only provides a new understanding of the rapid synthesis of highly luminescent Au20NCs but also demonstrates that the functionalized-Au20NCs are excellent probes for active tumor-targeted imaging in vitro and in vivo.
Co-reporter:Zhu Lian Wu, Ming Xuan Gao, Ting Ting Wang, Xiao Yan Wan, Lin Ling Zheng and Cheng Zhi Huang
Nanoscale 2014 vol. 6(Issue 7) pp:3868-3874
Publication Date(Web):20 Jan 2014
DOI:10.1039/C3NR06353D
A general quantitative pH sensor for environmental and intracellular applications was developed by the facile hydrothermal preparation of dicyandiamide (DCD) N-doped high quantum yield (QY) graphene quantum dots (GQDs) using citric acid (CA) as the carbon source. The obtained N-doped GQDs have excellent photoluminesence (PL) properties with a relatively high QY of 36.5%, suggesting that N-doped chemistry could promote the QY of carbon nanomaterials. The possible mechanism for the formation of the GQDs involves the CA self-assembling into a nanosheet structure through intermolecular H-bonding at the initial stage of the reaction, and then the pure graphene core with many function groups formed through the dehydration between the carboxyl and hydroxyl of the intermolecules under hydrothermal conditions. These N-doped GQDs have low toxicity, and are photostable and pH-sensitive between 1.81 to 8.96, giving a general pH sensor with a wide range of applications from real water to intracellular contents.
Co-reporter:Shao Qing Lie, Dong Mei Wang, Ming Xuan Gao and Cheng Zhi Huang
Nanoscale 2014 vol. 6(Issue 17) pp:10289-10296
Publication Date(Web):03 Jul 2014
DOI:10.1039/C4NR02294G
Copper chalcogenide nanocrystals (CuCNCs) as a type of semiconductor that can also act as efficient catalysts are rarely reported. Herein, we study water-soluble size-controlled Cu2−xSe nanocrystals (NCs), which are copper deficient and could be prepared by a redox reaction with the assistance of surfactants. We found them to have strong near-infrared localized surface plasmon resonance (LSPR) properties originating from the holes in the valence band, and also catalytic activity of more than a 500-fold enhancement of chemiluminescence (CL) in a luminol–H2O2 system. Investigations into the mechanisms behind these results showed that the high concentration of free carriers in Cu2−xSe NCs, which are derived from their high copper deficiencies that make Cu2−xSe NCs both good electron donors and acceptors with high ionic mobility, could greatly enhance the catalytic ability of Cu2−xSe NCs to facilitate electron-transfer processes and the decomposition of H2O2 into OH˙ and O2˙−, which are the commonly accepted key intermediates in luminol CL enhancement. Thus, it can be concluded that controllable copper deficiencies that are correlated with their near-infrared LSPR are critically responsible for the effective catalysis of Cu2−xSe NCs in the enhanced CL.
Co-reporter:Jun Wang, Peng Pei Gao, Xiao Xi Yang, Ting Ting Wang, Jian Wang and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 vol. 2(Issue 27) pp:4379-4386
Publication Date(Web):23 Apr 2014
DOI:10.1039/C4TB00221K
In this study, a targeted cancer therapy imaging and sensing system is designed based on doxorubicin (DOX)-loaded green fluorescent mesoporous silica nanoparticles (FMSN) conjugated with folic acid (FA), by linking with α-amine-ω-propionic acid hexaethylene glycol (NH2-PEG-COOH). An in situ formation method is adopted to prepare luminescent MSNs, which then act as the donor for the fluorescence resonance energy transfer (FRET), as their emission at 500 nm overlaps with the absorption of the acceptor DOX at 485 nm. NH2-PEG-COOH is conjugated to the outer surface of the FMSN at one end and modified by folic acid at the other, so that the formed mesoporous silica composite has the merits of fluorescence imaging, mesoporous nanostructure for drug loading, receptor-mediated targeting and real-time monitoring of intracellular drug release. It was found that the FA-grafted and PEGlated nanocomposite has excellent biocompatibility towards Hep2 cells, and that the cytotoxicity of the loaded-DOX nanoparticles, containing the folate targeting units in the folate-receptor-rich Hep2 cancer cells, is higher than that without folate targeting units, under the same conditions. When the resultant nanoparticles enter into the cells, the green fluorescence of FMSN gradually recovers along with the release of DOX, to achieve the purpose of real-time monitoring of intracellular drug release.
Co-reporter:Wen Long Li, Shao Qing Lie, Yu Qing Du, Xiao Yan Wan, Ting Ting Wang, Jian Wang and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 vol. 2(Issue 40) pp:7027-7033
Publication Date(Web):20 Aug 2014
DOI:10.1039/C4TB01099J
A facile aqueous chemical approach is developed for one-pot synthesis of the nanocomposites of heavily doped semiconductor nanoparticles (Cu2−xSe NPs) and reduced graphene oxide (rGO) at room temperature, wherein the reduction of GO and the in situ growth of Cu2−xSe NPs on rGO sheets occur simultaneously. The as-prepared Cu2−xSe/rGO nanocomposites exhibit a well-defined near-infrared (NIR) localized surface plasmon resonance (LSPR), which arises from free carriers (holes) and could be tuned from 1360 to 1050 nm by varying the reaction time, owing to the increase of the free carrier density in the valence band of Cu2−xSe NPs. This approach not only offers an efficient strategy to synthesize the self-doped Cu2−xSe/rGO nanocomposites with strong and tunable NIR absorption, but also develops new light scattering nanoprobes with good biocompatibility as well as unique optical properties for in vitro cellular dark-field microscopic imaging (iDFM).
Co-reporter:Jian Wang, Ting Ting Wang, Peng Fei Gao and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 vol. 2(Issue 48) pp:8452-8465
Publication Date(Web):29 Oct 2014
DOI:10.1039/C4TB01263A
Biomolecules perform vital functions in biology. These functional biomolecules with diverse modifications hold great promise for further applications in bioanalysis and cancer therapy. However, these functional biomolecules face challenges, especially in the field of drug delivery for cancer therapy. For example, functional biomolecules are typically unstable when taken up by cells, as they are easily digested by enzymes. To address this obstacle, nanomaterials have been employed as drug carriers or vehicles, which are powerful nanoplatforms for imaging and cancer treatment. Multifunctionality of these nanoplatforms offers great advantages over conventional reagents, including targeting to a diseased site to minimize systemic toxicity, and the ability to solubilize hydrophobic or labile drugs to improved pharmacokinetics. In this review, we summarize typical functional biomolecule-conjugated nanomaterials for targeting drug delivery. Under the appropriate conditions, targeted drug delivery can be achieved from a high density of biomolecules that are bound to the surface of nanomaterials, resulting in a high affinity for the targets. The high density of biomolecules then leads to a high local concentration, being able to prevent degradation by enzymes. Furthermore, biomolecule–nanomaterial conjugates have been identified to enter cells more easily than free biomolecules, and controllable drug release can then be obtained by a response to a stimulus, such as redox, pH, light, thermal, enzyme-trigged strategies. Now and in the future, with the development of artificial biomolecules as well as nanomaterials, targeted drug delivery based on elegant biomolecule–nanomaterial conjugation approaches is expected to achieve great versatility, additional functions, and further advances.
Co-reporter:Li Zhang, Sai Jin Xiao, Lin Ling Zheng, Yuan Fang Li and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 vol. 2(Issue 48) pp:8558-8565
Publication Date(Web):06 Oct 2014
DOI:10.1039/C4TB01310G
Fluorescent semiconductor quantum dot–graphene oxide (QD–GO) nanocomposites with unique optical properties can be prepared by a facile decoration of aptamer-labelled CdSe@ZnS QDs on GO nanosheets. The formation of such nanocomposites is based on the π–π stacking between the DNA bases on the QD surfaces and the GO. TEM and AFM were used to study the morphologies and distribution of the QDs on the GO surfaces. Steady-state fluorescence spectra, time-resolved fluorescence experiments and fluorescence imaging were employed to study the optical properties of the prepared aptamer-QD–GO nanocomposites. Furthermore, we investigate the potential applications of the nanocomposites in bio-imaging and cell-targeted drug delivery. The QDs decorated on the surfaces of GO could serve as fluorescent labeling probes for tracking the intracellular transport, while the GO combined with the aptamer conjugated on the outside of the nanocomposites facilitates the targeted drug delivery with enhanced loading capability. It is believed that the present aptamer-QD–GO nanocomposite-based nanomedicine would permit the development of more effective means for diagnosing and treating malignancies compared to the currently used methods.
Co-reporter:Lei Zhan, Chun Mei Li, Wen Bi Wu and Cheng Zhi Huang
Chemical Communications 2014 vol. 50(Issue 78) pp:11526-11528
Publication Date(Web):06 Aug 2014
DOI:10.1039/C4CC05155F
A novel colorimetric immunoassay for highly sensitive detection of respiratory syncytial virus (RSV), one of the leading causes of severe lower respiratory tract infections in all age groups, has been proposed based on Hg2+-stimulated peroxidase-like activity of gold nanoparticles–graphene oxide (AuNPs–GO) hybrids. This metal ion-enhanced immunoassay shows high promise in the field of biomedical sciences.
Co-reporter:Lin Ling Zheng, Xiao Xi Yang, Yue Liu, Xiao Yan Wan, Wen Bi Wu, Ting Ting Wang, Qiang Wang, Shu Jun Zhen and Cheng Zhi Huang
Chemical Communications 2014 vol. 50(Issue 99) pp:15776-15779
Publication Date(Web):28 Oct 2014
DOI:10.1039/C4CC06264G
An in situ labelling strategy was proposed to produce quantum dot-labelled respiratory syncytial viruses (RSVs) by incorporating the biotinylated membrane protein of the host cells into mature virions, followed by conjugation with streptavidin modified quantum dots (SA-QDs), which has the advantages such as convenience, efficiency and minor influence on viral infectivity and thus could be successfully applied to track the early stage of virus entry.
Co-reporter:Hui Yang, Peng Fei Gao, Wen Bi Wu, Xiao Xi Yang, Qiao Ling Zeng, Chong Li and Cheng Zhi Huang
Polymer Chemistry 2014 vol. 5(Issue 6) pp:1965-1975
Publication Date(Web):01 Nov 2013
DOI:10.1039/C3PY01335A
Synthetic polyacrylonitrile (PAN)/agar composite nanofibers were fabricated by introducing agar during the electrospinning process, and it was found that the nanofibers could be used for efficient, controlled drug release. Hydrophilic drugs such as ampicillin (AMC) were successfully encapsulated inside the agar, allowing the formation of uniform and smooth AMC/agar/PAN composite nanofibers. Cell viability assays showed that the as-prepared agar/PAN composite nanofibers had a good biocompatibility, and the antibacterial activity of the designed drug delivery system was investigated against Gram negative E. coli with a sustained release profile. The good biocompatibility and enhanced thermal properties—as well as the long-lasting antibacterial activity—of these agar/PAN composite nanofiber-containing drugs indicate their significant promise for a variety of potential medicinal applications. We believe that this approach could serve as a model technique in the fields of drug delivery and controlled release when considering the compatibility between polymers and drugs.
Co-reporter:Wei Wang, Fei Leng, Lei Zhan, Yong Chang, Xiao Xi Yang, Jing Lan and Cheng Zhi Huang
Analyst 2014 vol. 139(Issue 12) pp:2990-2993
Publication Date(Web):11 Mar 2014
DOI:10.1039/C4AN00113C
A one-step synthesis of water soluble and pH-responsive trypsin-stabilized fluorescent copper nanoclusters (CuNCs) was reported without using additional protective or reducing agents, and the as-prepared CuNCs exhibited highly stable properties including oxidation resistance, thermal stability and photostability.
Co-reporter:Jing Lan, Pu Zhang, Ting Ting Wang, Yong Chang, Shao Qing Lie, Zhu Lian Wu, Zhong De Liu, Yuan Fang Li and Cheng Zhi Huang
Analyst 2014 vol. 139(Issue 13) pp:3441-3445
Publication Date(Web):07 Apr 2014
DOI:10.1039/C4AN00505H
Water-soluble fluorescent silver nanoclusters (AgNCs) with almost seven and nine silver atoms and a quantum yield (QY) of 5.38 ± 0.25% were successfully prepared via one-pot hydrothermal synthesis using polymethacrylic acid sodium salt (PMAA-Na) as a template. The as-prepared PMAA–AgNCs displayed a mono-distribution, they were uniform in size and the color of the fluorescence, emitting at 579 nm, was orange when excited at 502 nm. What is more, we found that the as-prepared PMAA–AgNCs could be quenched by sulfides based on the formation of a metal–ligand bond Ag–S, and thus sulfides could be sensitively detected by spectrofluorometry. As proof of concept, thiourea (TU) and other sulfides including cysteine (Cys), glutathione (GSH) and DL-methionine could be detected. For example, the color of the orange fluorescent AgNCs solutions darkened upon the addition of TU and the fluorescence of PMAA–AgNCs was quenched. The detection limit for TU was 6.10 μM in the linear range from 8.57 μM to 2.29 mM.
Co-reporter:Hui Yang, Yue Liu, Peng Fei Gao, Jian Wang and Cheng Zhi Huang
Analyst 2014 vol. 139(Issue 11) pp:2783-2787
Publication Date(Web):21 Mar 2014
DOI:10.1039/C4AN00353E
Monitoring chemical reactions using tools of analytical chemistry is crucial for understanding the mechanisms of these reactions. In this study, leaf-like poly(p-phenylenediamine) (PpPD) microparticles were prepared with precisely tailored properties. The dark field microscopy protocol proved to be a powerful tool for studying the erosion of microparticles induced by Co2+. Such a protocol can have the benefit of improving the understanding of reaction mechanisms and can help expand the applications of dark field microscopy. A possible mechanism was proposed to explain the experimental observations.
Co-reporter:Lin Ling Zheng and Cheng Zhi Huang
Analyst 2014 vol. 139(Issue 23) pp:6284-6289
Publication Date(Web):30 Sep 2014
DOI:10.1039/C4AN01632G
Stringent alarmone, namely, guanosine 3′-diphosphate-5′-diphosphate (ppGpp), is a global regulator that plays a critical role in the survival, growth, metabolism, and many other vital processes of microorganisms. Because of its structural similarity to normal nucleotides, it is also a challenge for the selective and sensitive detection of ppGpp nowadays. Herein, we developed a colorimetric method for the selective detection of ppGpp by inhibiting the redox reaction between Fenton-like reagent (composed of Fe3+ and H2O2) with 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). Owing to the strong coordination affinity between ppGpp and Fe3+, the chromogenic reaction between ABTS and Fenton-like reagent, occurred in aqueous medium at 37 °C and resulted in a bluish-green solution, which was inhibited with the addition of ppGpp. This phenomenon forms the basis for the colorimetric detection of ppGpp, with a detection limit of 0.19 μM and good selectivity for ppGpp over other nucleotides and anions. Furthermore, the results could be visualized by the naked eye, and the sensitivity of the naked-eye observation could even be further improved with the aid of the introduction of a background color.
Co-reporter:Lei Zhan, Yan Zhang, Qiao Ling Zeng, Zhong De Liu, Cheng Zhi Huang
Journal of Colloid and Interface Science 2014 Volume 426() pp:293-299
Publication Date(Web):15 July 2014
DOI:10.1016/j.jcis.2014.03.056
•A green and facile method was demonstrated to synthesize reduced GO.•The FA-rGO sheets exhibited better biocompatibility.•The FA-rGO sheets were a more efficient energy acceptor than GO.•The FA-rGO sheets showed enhanced performance in H2O2 detection.A convenient and environment-friendly method is reported to synthesize the reduced graphene oxide (rGO) sheets in aqueous solution using folic acid (FA) as both a reducing and stabilizing agent, to improve the performance of graphene-based sensing strategy. The as-prepared FA-rGO sheets were characterized by transmission electron microscopy (TEM), UV–vis absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA), which provided the clear identification of the removal of oxygen-containing functional groups from the graphene oxide (GO) to form FA-rGO sheets. Further, it was found that the obtained FA-rGO sheets exhibited better biocompatibility and could act as the more efficient energy acceptor in long range resonance energy transfer (LrRET) process than that of graphene. Additionally, the FA-rGO can also catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2, and compared with GO sheets, they exhibited the more prominent intrinsic peroxidase-like activity, thus providing the more sensitive approach for colorimetric detection of H2O2.
Co-reporter:Jun Wang, Haiyang Liu, Fei Leng, Linling Zheng, Jinghua Yang, Wei Wang, Cheng Zhi Huang
Microporous and Mesoporous Materials 2014 Volume 186() pp:187-193
Publication Date(Web):1 March 2014
DOI:10.1016/j.micromeso.2013.11.006
•A new autofluorescent and pH-sensitive multifunctional drug release system developed.•Mesoporous silica composite formed by layer-by-layer assembly for cell tracing.•The nanocarriers are FA-targeting and pH-responsive release of the loaded drug.A new autofluorescent and pH-sensitive multifunctional drug release system is developed in this contribution by layer-by-layer assembly of chitosan (CHI)/dialdehyde starch (DAS) polyelectrolyte multilayers (PEM) onto mesoporous silica nanoparticles (MSN) surface. The formed mesoporous silica composites can be used as drug delivery carriers, which have very slow drug release rate at pH 7.4, but have very fast drug release rate at pH 5.0 owing to the breakage of CN bonds of the CHI/DAS multilayers under acidic condition. As a proof of concept, folic acid (FA) has been conjugated to the outer surface of the mesoporous silica composites by the amide reaction in order to deliver target anticancer drug, and it is found that cellular uptake of the folate conjugated doxorubicin-loaded nanoparticles in folate receptor-overexpressing HeLa cells is much higher than that of non-folate receptor-overexpressing A549 cells, indicating that successful targeting drug release has realized.Mesoporous silica nanoparticles (MSN) have attracted increasing interest as drug delivery vehicles due to high surface area, pore volume, and biocompatibility. In order to trace into cell, mesoporous silica hybrid materials use quantum dots (QDs) or dyes for cell tracing. To avoid the use of QDs or dyes for cell tracing, an autofluorescent mesoporous silica composite are formed by layer-by-layer assembly. The formed hybrid materials possesss properties of FA-targeting, pH-responsive release of the loaded drug and cell imaging.
Co-reporter:Yu Qing Du, Xiao Xi Yang, Wen Long Li, Jian Wang and Cheng Zhi Huang
RSC Advances 2014 vol. 4(Issue 66) pp:34830-34835
Publication Date(Web):25 Jul 2014
DOI:10.1039/C4RA06298A
Clinical therapies of cancers are generally unsatisfactory with poor patient compliance because of low therapeutic efficiency and strong side effects in normal tissues. To overcome these shortcomings and improve the efficacy of medicines, it is necessary to design some new targeting ligands, comparable to the folic acid ligand that is commonly used. Here we report a new drug delivery system for the targeted therapy of neuroblastoma cancer by functionalizing the surface of gold nanoparticles (AuNPs) with DNA that contains cellular prion protein (PrPC) aptamers. Owing to the specific identification between the aptamer and PrPC expressed on the surface of human bone marrow neuroblastoma (SK-N-SH) cells, the DNA–drug conjugates were delivered to the target cancer cells, and thus apoptosis of these cells occurred. The in vitro toxicity assay and fluorescence imaging results showed that the AuNP mediated DNA–doxorubicin conjugates (AuNPs–DNA(Dox)) could be demonstrated as a specific and effective therapeutic agent for neuroblastoma cancer.
Co-reporter:Hui Yang and Cheng Zhi Huang
RSC Advances 2014 vol. 4(Issue 73) pp:38783-38790
Publication Date(Web):06 Aug 2014
DOI:10.1039/C4RA05737F
Nanofiber matrix loading Ag nanoparticles have been applied for SERS measurements with the limitation of poor reproducibility. By introducing polymethacrylic acid (PMAA) into the electrospun solutions in this contribution, fairly uniform PMAA/poly(N-vinylpyrrolidone) (PVP) ultrafine fibers containing silver nanoparticles (AgNPs) were successfully prepared via electrospinning by means of in situ photo reduction of silver ions. PMAA can significantly improve the absorbing amounts of silver ions in the polymer owing to its linear structure with abundant carboxyl groups, which makes the content and size of formed AgNPs in the polymer matrix to be easily controlled under different light sources (such as desk lamp, 365 nm UV lamp, and 254 nm UV lamp). With the electrospun AgNPs/PMAA/PVP fibrous membranes, malachite green (MG), a significant environmental organic pollutant known for its genotoxicity, was successfully detected with RSD values below 0.2% through SERS signals.
Co-reporter:Shao Qing Lie, Hong Yan Zou, Yong Chang and Cheng Zhi Huang
RSC Advances 2014 vol. 4(Issue 98) pp:55094-55099
Publication Date(Web):09 Oct 2014
DOI:10.1039/C4RA05828C
In this paper, negatively charged Cu2−xSe nanoparticles (NPs), stabilized by poly(styrene sulfonic acid)sodium (PSS) (PSS–Cu2−xSe NPs), were synthesized via a simple templated method, which exhibited strong localized surface plasmon resonance (LSPR) absorption in the near-infrared (NIR) region. It was found that the prepared PSS–Cu2−xSe NPs could be aggregated by lysozymes (Lys) selectively through the electrostatic interaction, since the Lys was positively charged in a neutral medium, producing a red shift of the LSPR band starting from 980 nm to 1300 nm area. With different concentrations of Lys, the LSPR band can be dynamically tuned, and the absorbance ratio of A1300/A980 has a good linear relationship with the concentration of Lys in the range of 5–100 nM, thus supplying an effective way to tune LSPR in the NIR region of semiconductors that might be applied for sensing and photothermal conversion sciences and technologies in the NIR region.
Co-reporter:Wen Liang Fu, Shu Jun Zhen and Cheng Zhi Huang
RSC Advances 2014 vol. 4(Issue 31) pp:16327-16332
Publication Date(Web):11 Mar 2014
DOI:10.1039/C4RA00658E
In this contribution, a new simple and cost-effective strategy for the preparation of hybrids of graphene oxide (GO) and metal nanoparticles (MNPs) through the mediation of polyethyleneimine (PEI) molecules was reported. PEI molecules as cationic polymers could effectively attach onto the surface of GO for further negative MNP adsorption. By this process, gold and silver nanoparticles are assembled on GO with high efficiency. This method has also been successfully applied to the assembly of metal nanoparticles and carbon nanotubes (CNTs), indicating that this method is general. Furthermore, the as-prepared graphene oxide/silver nanoparticle (GO/AgNP) hybrids have been used as perfect surface enhanced Raman scattering (SERS) substrates with an enhancement factor of 1.5 × 105 and successfully applied for the sensitive and selective detection of 6-mercaptopurine (6MP) in pharmaceutical tablets with satisfactory results.
Co-reporter:Lei Zhan, Wen Bi Wu, Xiao Xi Yang and Cheng Zhi Huang
New Journal of Chemistry 2014 vol. 38(Issue 7) pp:2935-2940
Publication Date(Web):07 Apr 2014
DOI:10.1039/C4NJ00253A
Respiratory syncytial virus (RSV) mediates severe respiratory illness in infants and young children worldwide, and it is also a significant pathogen of the elderly and immune compromised. Due to the low infectious dose and high infectious rate of RSV, remarkably rapid and sensitive RSV detection is important for infection control and discovery of antiviral drugs. In this work, we described a highly sensitive enzyme-linked immunosorbent assay (ELISA) utilizing gold nanoparticles (AuNPs) for the detection of RSV. Gold nanoparticles were used as carriers of the signalling antibody anti-RSV–HRP (horseradish peroxidase) in order to achieve an amplification of the signal. Compared to conventional ELISA procedures, this assay resulted in higher sensitivity and shorter assay time in the range between 0.5 and 50 pg mL−1. The application of AuNPs to the enhanced ELISA showed acceptable reproducibility, stability, and could be readily applied to determination of other pathogens in clinical diagnostics.
Co-reporter:Xi Juan Zhao and Cheng Zhi Huang
New Journal of Chemistry 2014 vol. 38(Issue 8) pp:3673-3677
Publication Date(Web):22 May 2014
DOI:10.1039/C4NJ00731J
A one step synthesis of water-soluble luminescent copper nanoclusters (CuNCs) reduced and protected by histidine is reported. When excited at 350 nm, the as-synthesized CuNCs exhibit luminescence centered at 456 nm with a quantum yield of 1.6%, which is different from that of histidine alone under the same experimental conditions. Upon addition of guanosine 5′-triphosphate (GTP), the emission of CuNCs is gradually quenched. While other nucleoside triphosphates including ATP, CTP and UTP as well as some inorganic anions such as P2O74−, PO43−, and CH3COO− have no such quenching effect, which indicates that the nucleobase instead of the phosphate anion plays an important role in the emission quenching of CuNCs. The most efficient quenching of the CuNCs induced by GTP can be ascribed to the most reducing ability of guanine among the other nucleobases. This interesting experimental result demonstrates that the as-synthesized CuNCs can be applied to sensing of GTP.
Co-reporter:Wen Bi Wu, Lei Zhan, Jian Wang and Cheng Zhi Huang
Analytical Methods 2014 vol. 6(Issue 11) pp:3779-3783
Publication Date(Web):25 Mar 2014
DOI:10.1039/C4AY00206G
A simple and label-free plasmon resonance light scattering (PRLS) assay for glucose was developed based on the formation of gold nanoparticles (AuNPs) from the redox between chlorauric acid (HAuCl4) and hydrogen peroxide (H2O2) in the presence of MES. It was found that the PRLS signals characterized at 550 nm were proportional to the content of H2O2, which could be produced in the process of biocatalytic reaction of glucose oxidase (GOx), and thus a RLS method of glucose was proposed with the linear range of 5.0 × 10−6 M to 1.0 × 10−4 M and the detection limit of 2.7 × 10−6 M.
Co-reporter:Lin Yang, Shu Jun Zhen, Zhong De Liu and Cheng Zhi Huang
Analytical Methods 2014 vol. 6(Issue 14) pp:5054-5058
Publication Date(Web):11 Apr 2014
DOI:10.1039/C4AY00181H
We report a simple Raman scattering method for the sensitive and selective detection of cobalt(II) ions using the combination of leaf-like poly(p-phenylenediamine) (PpPD) microcrystals and Ag nanoparticles (AgNPs) as the signal provider. The AgNPs provide much greater Raman scattering enhancement to the PpPD microparticles. However, it was found that the PpPD microparticles can be selectively etched and degraded by cobalt(II) ions, resulting in a decrease in Raman signal intensity. Therefore, the combination of PpPD microparticles and AgNPs provides an excellent Raman scattering signal readout platform for sensitive and specific cobalt(II) detection, and the decrease in Raman signal intensity is found to be proportional to the logarithm of cobalt(II) concentration over the range of 0.3–50 μM with a detection limit (3σ) of 20 nM.
Co-reporter:Hong Wang, Dong Mei Wang, Ming Xuan Gao, Jian Wang and Cheng Zhi Huang
Analytical Methods 2014 vol. 6(Issue 18) pp:7415-7419
Publication Date(Web):09 Jul 2014
DOI:10.1039/C4AY01411A
A simple and highly selective chemiluminescence (CL) detection method for K+ was developed based on a K+-stabilized G-qaudruplex DNAzyme, which catalyzes a luminol-H2O2 reaction system. Herein, a G-quadruplex DNAzyme stemming from a common guanine-rich DNA sequence named PS2.M is introduced as a catalyst. Upon the addition of K+, PS2.M is induced to fold into G-quadruplex as a cofactor binding with hemin, effectively catalyzing the redox reaction of luminol-H2O2. The reaction generates a CL emission and allows the DNAzyme to show a good horseradish peroxidase (HRP) mimicking-enzyme activity. The intensity of CL shows a linear dependence on the concentration of K+ within the range of 2–120 μM with a limit of detection (3σ) of 1.66 μM, giving a vital clue to quantify K+ content in urine samples. This strategy firstly opens up CL as an effective and facile approach to detect K+ with high selectivity.
Co-reporter:Chun LIU, Cheng-Zhi HUANG
Chinese Journal of Analytical Chemistry 2014 Volume 42(Issue 8) pp:1195-1198
Publication Date(Web):August 2014
DOI:10.1016/S1872-2040(14)60760-X
In this paper, a sensitive method for the detection of lead ions in aqueous solution based on the surface energy transfer between gold nanoparticles and fluorescent dyes was established. The fluorescein-modified thrombin aptamer (5′-FAM-GGTTGGTGTGGTTGG-3′) could be selectively transformed to G-quadruplex structure in the presence of lead ions. The conformational change of the aptamer could alter the distance between the energy donor of fluorescent dyes and the energy receptor of gold nanoparticles, resulting in an enhanced fluorescence intensity. The fluorescence recovery efficiency (F/F0) was proportional to the concentration of lead ions in the range of 12.5−100 nM. The linear regression equation was y = 0.910 + 0.007c (R2 = 0.997) with the limit of detection (3σ) of 10 nM. The proposed method was applied to the determination of lead ions in tap water with satisfactory results.The thrombin-binding aptamer wasselectively transferred from random coil to G-quadruplex structure induced by lead ions, which alter the distances and energy transfer efficiencies between FAM-TBA and gold nanoparticles.
Co-reporter:Wei Wang;Xiao Li Yan;Lei Zhan;Fei Leng;Xiao Xi Yang
Science Bulletin 2014 Volume 59( Issue 2) pp:147-153
Publication Date(Web):2014 January
DOI:10.1007/s11434-013-0052-1
A new type of highly selective aptamer-labeled fluorescent silica nanoparticles [Apt-tris(2,2′-bipyridyl)ruthenium(II)@SiO2 NPs] were prepared through the reverse microemulsion method by using prolonged fluorescence lifetime ruthenium complexes of tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) as the source of the fluorescence for cellular prion protein imaging. Investigations showed that the newly prepared Ru(bpy)32+@SiO2 NPs possessed superior advantages of strong fluorescence, low toxicity, and easy surface modification for bioconjugation. Cell imaging experiments indicated that Apt-Ru(bpy)32+@SiO2 NPs had great tendency to human bone marrow neuroblastoma cells (SK-N-SH cells), since they can express large amount of prion protein on the surface of the cell, while in HeLa cells this phenomenon disappeared for the reason that HeLa cells cannot express prion proteins.
Co-reporter:Lei Zhan;Li Peng;Cheng-Zhi Huang
Science Bulletin 2014 Volume 59( Issue 10) pp:964-970
Publication Date(Web):2014 April
DOI:10.1007/s11434-014-0122-z
Combining the unique optical properties of metal nanoparticles and the specific recognition of aptamer, aptamer–nanoparticle conjugates have been extensively used in a wide range of applications, particularly multifunctional nanoparticles for cell detection and molecular imaging. Conventional conjugates prepared by chemisorption of monothiol-modified oligonucleotides onto nanoparticle surfaces suffer from a lack of stability when exposed to a variety of small molecules. If silver is used in place of gold, then this lack of stability is even more pronounced. In this study, we reported here the effective and facile strategy of preparing stable silver nanoparticle–aptamer conjugates by in situ generation of strong metal affinity capping ligands, dithiocarbamates modified anti-prion protein aptamer. The conjugates produced are stable and can withstand NaCl concentration at 0.25 mol/L. Meanwhile, they could be applied in the cellular prion protein imaging successfully.
Co-reporter:Li Zhang, Ru-Ping Liang, Sai-Jin Xiao, Jian-Mei Bai, Lin-Ling Zheng, Lei Zhan, Xi-Juan Zhao, Jian-Ding Qiu, Cheng-Zhi Huang
Talanta 2014 Volume 118() pp:339-347
Publication Date(Web):15 January 2014
DOI:10.1016/j.talanta.2013.09.021
•We prepare the fluorescent indicator facilely and economically.•We propose a simple, sensitive and specific assay for OH.•We extensively study and reveal the sensing mechanism.•We design the fluorescent probe for intracellular imaging of OH.We have developed a simple, rapid and label-free sensor for the essential biological OH radicals based on the fluorescence quenching of DNA-templated Ag nanoclusters (DNA-Ag NCs). The OH radicals generated from the Fenton reagent attack and cleave the DNA template, which disturbs the microenvironments around Ag NCs, resulting in spontaneous aggregation due to the lack of stabilization and further the quenching of the Ag NCs fluorescence. These changes in fluorescence intensity allow sensing of OH radicals with good sensitivity and selectivity under optimal conditions. The sensor can be also applied for quantifying the radical scavenging action of antioxidants. Various characterizations including absorption spectra, fluorescence lifetimes, light scattering (LS) spectra, transmission electron microscopy (TEM), dark field light scattering imaging, and circular dichroism (CD) spectrometry have been employed to illustrate the proposed sensing mechanism. Further investigations demonstrate that the fluorescent probe could penetrate into intact cell membranes to selectively detect intracellular OH radicals induced by the phorbol myristate acetate (PMA) stimulation. These advantageous characteristics make the fluorescent DNA-Ag NCs potentially useful as a new candidate to monitor OH in broad biosystems.
Co-reporter:Zhu Lian Wu, Pu Zhang, Ming Xuan Gao, Chun Fang Liu, Wei Wang, Fei Leng and Cheng Zhi Huang
Journal of Materials Chemistry A 2013 vol. 1(Issue 22) pp:2868-2873
Publication Date(Web):23 Apr 2013
DOI:10.1039/C3TB20418A
Nitrogen-doped carbon dots (CDs) have attracted great interest due to their extraordinary properties, especially their enhanced emission efficiency, and thus a facile synthesis of nitrogen-doped CDs with high emission efficiency is critical for practical applications. To improve the emission efficiency of CDs, herein we employed Bombyx mori silk, which has high nitrogen content, as a raw material to prepare photoluminescent nitrogen-doped carbon dots through one-pot hydrothermal synthesis, and found that the as-prepared CDs have a photoluminescence (PL) quantum yield of 13.9%, and display amphoteric properties depending on the pH, are highly photostable, have low toxicity and are suitable for bioimaging.
Co-reporter:Peng Fei Gao, Lin Ling Zheng, Li Jiao Liang, Xiao Xi Yang, Yuan Fang Li and Cheng Zhi Huang
Journal of Materials Chemistry A 2013 vol. 1(Issue 25) pp:3202-3208
Publication Date(Web):07 May 2013
DOI:10.1039/C3TB00026E
A new type of coordination polymer sphere prepared by combining 1,1′-(1,4-butanediyl)bis(imidazole) (bbi) and ferrous ions has been demonstrated as a targeted delivery system for in situ encapsulating anticancer drugs. These stable coordination polymer spheres can be fabricated simply by a deposition method. Drugs, doxorubicin hydrochloride (DOX·HCl) for example, can be easily in situ encapsulated by simply mixing the drug with bbi ligand through the deposition method and results in a high drug loading efficiency up to 98% and a drug loading content of nearly 40%, which is remarkably high for not only metal–organic but also other materials. A noticeable feature of the drug loaded coordination polymer spheres is that they show sustainable drug release for several days due to their superior stability, and are sensitive to external pH owing to the coordination bonds. The drug can be released faster in mild acidic conditions in comparison to physiological acidity. By conjugating folic acid to the surface of the coordination polymer spheres, the vehicles can be taken up selectively by cancer cells through cell surface receptor-mediated mechanisms. Cell viability experiments with HeLla cells demonstrated the low toxicity of the delivery vehicles and the good anticancer efficacy of the drug-loaded coordination polymer spheres.
Co-reporter:Yue Liu and Cheng Zhi Huang
Nanoscale 2013 vol. 5(Issue 16) pp:7458-7466
Publication Date(Web):17 Jun 2013
DOI:10.1039/C3NR01952G
Understanding the localized surface plasmon resonance (LSPR) of differently shaped plasmonic nanoparticles benefits screening and designing highly sensitive single nanoparticle sensors. Herein, in the present work, we systematically investigated the shape-dependent scattering light colours and refractive index (RI) sensitivity of Ag nanoparticles (AgNPs) at the single nanoparticle level using conventional dark-field light scattering microscopy and spectroscopy. AgNPs in various shapes and scattering colourful light were synthesized, and the shape effect on the scattering light colour was determined by the colocalization of the same nanoparticles with dark-field microscopy (DFM) and scanning electron microscopy (SEM). The results showed that the AgNPs that scattered blue, cyan, yellow, and red light are spheres, cubes, triangular bipyramids, and rods, respectively, which enable us to directly recognize the shape of AgNPs through dark-field microscopy instead of electron microscopy. Further studies on investigation of the scattering spectral responses of single AgNPs to their surrounding solvents show that the RI sensitivity of AgNPs of different shapes followed the order of rods > cubes > triangular bipyramids > spheres. Among the commonly studied AgNPs, Ag nanorods have the highest RI sensitivity, which increases as the aspect ratio increases. Then, AgNPs of various shapes were used as single nanoparticle sensors for probing the adsorption of small molecules.
Co-reporter:Yan Yu, Yue Liu, Shu Jun Zhen and Cheng Zhi Huang
Chemical Communications 2013 vol. 49(Issue 19) pp:1942-1944
Publication Date(Web):21 Jan 2013
DOI:10.1039/C3CC38129C
Graphene oxide (GO) introduced to enhance the fluorescence anisotropy (FA) of fluorogens was identified to be effective for highly sensitive and selective detection of metal ions through an anisotropy DNAzyme-based strategy.
Co-reporter:Ming Xuan Gao, Chun Fang Liu, Zhu Lian Wu, Qiao Ling Zeng, Xiao Xi Yang, Wen Bi Wu, Yuan Fang Li and Cheng Zhi Huang
Chemical Communications 2013 vol. 49(Issue 73) pp:8015-8017
Publication Date(Web):11 Jul 2013
DOI:10.1039/C3CC44624G
Highly PL carbon quantum dots (CQDs) were successfully prepared from C60 by introducing CTAB and H2O2 in aqueous NaOH under hydrothermal conditions. The CQDs displayed a nanoparticle aggregation-induced emission enhancement (NP-AIEE).
Co-reporter:Yue Liu and Cheng Zhi Huang
Chemical Communications 2013 vol. 49(Issue 74) pp:8262-8264
Publication Date(Web):12 Jul 2013
DOI:10.1039/C3CC43605E
Single gold nanoparticles (AuNPs), whose scattering light intensity was digitized and expressed as digital information through common software, were used as digital recorders for probing molecular binding of avidin to biotin.
Co-reporter:Jian Wang, Yuan Fang Li, Cheng Zhi Huang, Tong Wu
Analytica Chimica Acta 2013 Volume 785() pp:126
Publication Date(Web):27 June 2013
DOI:10.1016/j.aca.2013.05.001
Co-reporter:Ping Ping Hu, Lin Ling Zheng, Lei Zhan, Jing Yun Li, Shu Jun Zhen, Hui Liu, Ling Fei Luo, Geng Fu Xiao, Cheng Zhi Huang
Analytica Chimica Acta 2013 Volume 787() pp:239-245
Publication Date(Web):17 July 2013
DOI:10.1016/j.aca.2013.05.061
•We report a solution-based MEF sensing platform.•Metallic surface-dye distance is controlled by changing the thickness of silica shell.•Dual-aptamer was involved to recognize distinct binding epitopes of the same target.•Ag@Si NPs was used as an excellent probe for darkfield light scattering imaging.Metal-enhanced fluorescence (MEF) as a newly recognized technology is widespread throughout biological research. The use of fluorophore–metal interactions is recognized to be able to alleviate some of fluorophore photophysical constraints, favorably increase both the fluorophore emission intensity and photostability. In this contribution, we developed a novel metal-enhanced fluorescence (MEF) and dual-aptamer-based strategy to achieve the prion detection in solution and intracellular protein imaging simultaneously, which shows high promise for nanostructure-based biosensing. In the presence of prion protein, core–shell Ag@SiO2, which are functionalized covalently by single stranded aptamer (Apt1) of prions and Cyanine 3 (Cy3) decorated the other aptamer (Apt2) were coupled together by the specific interaction between prions and the anti-prion aptamers in solution. By adjusting shell thickness of the pariticles, a dual-aptamer strategy combined MEF can be realized by the excitation and/or emission rates of Cy3. It was found that the enhanced fluorescence intensities followed a linear relationship in the range of 0.05–0.30 nM, which is successfully applied to the detection of PrP in mice brain homogenates.Metal-enhanced fluorescence of core–shell structure of Ag@Si NPs was proposed for the detection and cellular imaging of prion protein with a dual aptamer strategy, which shows high promise for nanostructure-based biosensing.
Co-reporter:Lei Zhan, Li Jiao Liang, Shu Jun Zhen, Chun Mei Li and Cheng Zhi Huang
Analyst 2013 vol. 138(Issue 3) pp:825-830
Publication Date(Web):28 Nov 2012
DOI:10.1039/C2AN36322D
A new spectrofluorometric method for cellular prion protein (PrPC) was developed based on the regulation of N,N′-bis[3,3′-(dimethylamino)propylamine]-3,4,9,10-perylenetetracarboxylic diimide (DAPER) fluorescence. As a perylene derivative, DAPER emits strong fluorescence in the form of free monomer in aqueous medium, but not in the form of aggregates. In this contribution, we found that the aptamer of PrPC could induce the aggregation of DAPER, and the bright fluorescence of DAPER was completely quenched. The quenched fluorescence, however, was recovered if PrPC was further added, which was ascribed to the specific binding of PrPC to its aptamer and the releasing of free DAPER monomers. This signalling mechanism makes it possible to detect PrPC by fluorescence spectroscopy. The assay allows the selective determination of PrPC in aqueous solution with high sensitivity and exhibits a good linear range from 0.4 to 1.6 nmol L−1. Moreover, this probe can be applied to monitor the level of PrPC in human urine samples with satisfactory results.
Co-reporter:Ya Wen Zhou, Chun Mei Li, Yue Liu and Cheng Zhi Huang
Analyst 2013 vol. 138(Issue 3) pp:873-878
Publication Date(Web):19 Nov 2012
DOI:10.1039/C2AN36456E
Silver nanoclusters (AgNCs) have gained considerable attention over a wide range from chemical detection to bioimaging applications. Herein we developed a facile way to synthesize water-soluble, intense fluorescent targetable AgNCs with yellow-emission by using DNA via a chemical reduction method. The sequence of DNA was designed to contain two fragments, one of which is the DNA aptamer fragment which can selectively bind to the target, and the other is rich in cytosine sequence fragments that can result in a high quantum efficiency. The as-prepared targetable AgNCs (Apt-AgNCs) through the reduction of silver ions (Ag+) by NaBH4 have a very strong fluorescence emission, which, was greatly quenched upon specific binding to prion protein (PrPC). As a result, Apt-AgNCs were demonstrated as a novel, effective and sensitive probe for both detection and intracellular fluorescent imaging with high selectivity through the strong binding affinity between the aptamer and its target.
Co-reporter:Wen Liang Fu, Shu Jun Zhen and Cheng Zhi Huang
Analyst 2013 vol. 138(Issue 10) pp:3075-3081
Publication Date(Web):15 Mar 2013
DOI:10.1039/C3AN00018D
In this contribution, graphene oxide/gold nanoparticle (GO/AuNPs) hybrids were in situ fabricated through a green one-pot procedure by using tyrosine as an environment friendly and biocompatible reducing agent, which can be used as highly efficient surface enhanced Raman scattering (SERS) substrates with the enhancement factor at 3.8 × 103. The as-prepared GO/AuNPs hybrids have good biocompatibility, providing the prospect of applications for biomedicine determinations. In addition, taking the advantages of the electromagnetic and chemical enhancement mechanism and the high affinity of GO and AuNPs towards positive dyes, a sensitive, selective and label-free malachite green (MG) detection method was demonstrated. The SERS measurement showed that the minimum detection concentration of MG in water was as low as 2.5 μmol L−1 with a linear response range from 2.5 to 100 μmol L−1 (R2 = 0.996). Moreover, this method can be applied to detect MG in a fishery water sample with satisfactory results.
Co-reporter:Yu Qing Du, Peng Fei Gao, Wei Wang, Ting Ting Wang, Yong Chang, Jian Wang and Cheng Zhi Huang
Analyst 2013 vol. 138(Issue 19) pp:5745-5750
Publication Date(Web):08 Jul 2013
DOI:10.1039/C3AN00763D
Polymerase chain reaction (PCR) has been widely used for detecting long chain DNA or RNA of viruses, bacteria and cytokines, but it is difficult to detect DNA or RNA with short length sequences. In this work, we developed a simple and rapid detection method for short length DNA sequences in complicated matrices based on ligation-mediated PCR. Two probes, both designed as 52 bases and respectively partly complementary to the half-sequence of target DNA, could simultaneously hybridize to the target DNA, then to be ligated by T4 DNA ligase to form a long chain as PCR template for amplification. With the specific hybridization of the two probes and target DNA, and the PCR going on, a target with 16 bases was selectively detected with content as low as 200 fM, and the linear range spanned over five orders of magnitude. This method was successfully applied to the detection of target DNA in complicated biological samples such as cell lysate with satisfactory results.
Co-reporter:Xi Juan Zhao, Rong Xing He, Ming Li, Ning Wei Zhao, Yuan Fang Li and Cheng Zhi Huang
RSC Advances 2013 vol. 3(Issue 1) pp:111-116
Publication Date(Web):30 Oct 2012
DOI:10.1039/C2RA21918B
Iron is known to be indispensable for life since its levels are related to biochemical, pharmacological and toxicological functions in the organisms. Herein, we demonstrate a very simple visual detection method of iron(II) cations (Fe2+) with high specificity based on its etching effects on the blue fluorescent ribbon aggregates of 4′,4′′′′-(1,4-phenylene) bis(2,2′:6′,2′′-terpyridine) (PBTPy). PBTPy, a terpyridine attached molecule, is observed to form blue fluorescent ribbon aggregates in a pH-modulated solvent of DMSO/H2O. Owing to the complexing of two terpyridine functional groups with Fe2+, the aggregates of PBTPy are gradually “etched” by Fe2+, giving new absorption bands at around 576 nm, 582 nm and 610 nm with a color change from purple to blue and then to cyan, depending on the content of Fe2+. This response is highly specific for Fe2+ over many other metal ions, including Fe3+, and thus successfully applied to the detection of Fe2+ released from the ferritin.
Co-reporter:Yi Wang, Pu Zhang, Chun Fang Liu and Cheng Zhi Huang
RSC Advances 2013 vol. 3(Issue 24) pp:9240-9246
Publication Date(Web):08 Apr 2013
DOI:10.1039/C3RA22687E
The self-assembly of two-dimensional (2D) graphene sheets into three-dimensional (3D) structures is an effective approach to fabricate graphene-based hierarchical architectures for practical applications. Here we report an easy and environmentally friendly method to fabricate a graphene-based multifunctional hydrogel using a biocompatible polysaccharide as both a stabilizer and a physical cross-linking agent. The as-prepared hydrogel is highly stable in a variety of harsh conditions such as strong acid, strong alkali, high ion strength solution, and organic solvent. Moreover, it shows excellent dye adsorption and antibacterial capability, and has been successfully used for miniature-scale water purification. The present work provides a new insight for the self-assembly of functionalized graphene with biomolecules, offering an alternative way to fabricate multifunctional materials for a wide range of applications.
Co-reporter:Hong Lin Zhuang, Shu Jun Zhen, Jian Wang and Cheng Zhi Huang
Analytical Methods 2013 vol. 5(Issue 1) pp:208-212
Publication Date(Web):06 Nov 2012
DOI:10.1039/C2AY26156A
The traditional molecular aptamer beacon (MAB) is designed by combining an aptamer to a molecular beacon, and its two terminals are labelled with a fluorescent moiety (donor) and quenching moiety (acceptor), respectively. However, it usually has a high background because of the low energy transfer efficiency between the donor and the acceptor. In order to overcome these drawbacks, we have developed a novel MAB with just one fluorescently labelled end, which acts as the donor, and graphene oxide (GO) introduced as the acceptor for target detection by employing long range resonance energy transfer (LrRET) as the signal-transduction mechanism from GO to MAB. To test the validity of the designed MAB system, cellular prion protein (PrPC) has been used as the model target. It was found that the fluorescence of the designed MAB is completely quenched by GO, supplying a very low background. Conversely, the quenched fluorescence is recovered significantly with the addition of PrPC, so that PrPC can be detected over a wide range of 10.2–78.8 μg mL−1 with a detection limit as low as 0.309 μg mL−1 and with high selectivity. This GO-based MAB approach is a successful application of LrRET for the detection of PrPC, with advantages such as low costs, high quenching efficiency and good specificity, and it opens up new opportunities for the sensitive detection of biorecognition events.
Co-reporter:Ming Xuan Gao, Jia Li Xu, Yuan Fang Li and Cheng Zhi Huang
Analytical Methods 2013 vol. 5(Issue 3) pp:673-677
Publication Date(Web):19 Nov 2012
DOI:10.1039/C2AY25971K
Developing new detection methods for drugs is compulsory in terms of pharmacological investigation and quality control. In this contribution, we developed a new spectrofluorometric method for 6-mercaptopurine (6-MP), an anticancer drug, by using CdTe quantum dots (QDs). It was found that the fluorescence of surface-carboxyl CdTe QDs could be effectively quenched by Cu2+ due to aggregation, but restored in the presence of 6-MP, due to the reduction of copper ions into cuprous ions by the disulfide of 6-MP. The restored fluorescence intensity had a linear relationship with the concentration of 6-MP in the range of 0.20–3.20 μmol L−1. With that, a new rapid sensitive spectrofluorometric method for 6-MP was developed.
Co-reporter:Wei Wang, Lei Zhan, Yu Qing Du, Fei Leng, Yong Chang, Ming Xuan Gao and Cheng Zhi Huang
Analytical Methods 2013 vol. 5(Issue 20) pp:5555-5559
Publication Date(Web):12 Aug 2013
DOI:10.1039/C3AY41146J
In this paper, a new approach for respiratory syncytial virus (RSV) gene sequence detection was described based on the fluorescence resonance energy transfer (FRET) from oligonucleotide-templated silver nanoclusters (DNA–AgNCs) to multi-walled carbon nanotubes (MWCNTs). The specific DNA scaffold combines two fragments: one is enriched with a cytosine sequence fragment (C12) that can result in DNA–AgNCs with a high quantum yield via a chemical reduction method, and the other is the probe fragment (5′-AAA AAT GGG GCA AAT A-3′) which can selectively bind to the gene for RSV. Thus, the as-prepared AgNCs can exhibit enhanced fluorescence when binding to the target DNA sequence and forming a double helix. Because of the introduction of MWCNTs, which can quench the fluorescence of the DNA–AgNCs with an extraordinarily high quenching efficiency (85.8%), a relatively high signal-to-background ratio was achieved. The fluorescence ratio of the DNA–AgNCs was enhanced in a linearly proportional manner to the concentration of the target in the range of 31.25 nM to 2.00 μM with a detection limit (3σ) of 24.00 nM.
Co-reporter:Yong Chang, Pu Zhang, Yan Yu, Yu Qing Du, Wei Wang and Cheng Zhi Huang
Analytical Methods 2013 vol. 5(Issue 21) pp:6200-6204
Publication Date(Web):09 Sep 2013
DOI:10.1039/C3AY41219A
Noble metal nanoclusters, which have molecule-like properties and offer the missing understanding link between metal atoms and nanoparticles, have become a hot research topic due to their amazing properties. Herein, we develop a label-free, low-cost and sensitive fluorescence turn-off strategy for the detection of bleomycin (BLM) with strong fluorescent silver nanoclusters, wherein BLM coordinated with Fe2+ could highly oxidize the core of fluorescent silver nanoclusters. Under the optimal conditions, this strategy could be applied to the detection of BLM in the range of 100 to 400 nM with a detection limit of 54 nM.
Co-reporter:Shu Jun Zhen, Hong Lin Zhuang, Jian Wang and Cheng Zhi Huang
Analytical Methods 2013 vol. 5(Issue 24) pp:6904-6907
Publication Date(Web):09 Oct 2013
DOI:10.1039/C3AY41335G
We developed a new dual-aptamer based strategy to detect cellular prion protein through the fluorescence resonance energy transfer between quantum dots and graphene oxide, in which the distance between the energy donor and the acceptor ranges from 14 to 27 nm.
Co-reporter:Dr. Jian Wang;Dr. Kwame Sefah;Dr. Meghan B. Altman;Tao Chen;Dr. Mingxu You;Dr. Zilong Zhao; Cheng Zhi Huang; Weihong Tan
Chemistry – An Asian Journal 2013 Volume 8( Issue 10) pp:2417-2422
Publication Date(Web):
DOI:10.1002/asia.201300375
Abstract
Prostate cancer results in about 30 000 deaths annually in the United States, making it the second leading cause of cancer mortality in men in the Western world. Therefore, it is of great significance to capture and kill prostate cancer cells. It is well known that cancer stem cells are responsible for the maintenance and metastasis of tumors. This concept offers the possibility of developing a selective therapeutic approach in which cancer stem cells are directly targeted and killed. In this work, aptamers selected against DU145 prostate cancer cells (aptamer CSC1) and their subpopulation of cancer stem cells (aptamer CSC13) were linked to the surfaces of gold nanorods (AuNRs), and the resulting conjugates were successfully used to target and kill both cancer cells and cancer stem cells by near-infrared (NIR) laser irradiation. Even though cancer stem cells represent only a small population among all cancer cells, the entire cell viability was very low after laser irradiation, suggesting that tumorigenesis could be successfully controlled by this aptamer-based method, thus paving the way for early diagnosis and targeted therapy.
Co-reporter:Chun Mei Li, Shu Jun Zhen, Jian Wang, Yuan Fang Li, Cheng Zhi Huang
Biosensors and Bioelectronics 2013 Volume 43() pp:366-371
Publication Date(Web):15 May 2013
DOI:10.1016/j.bios.2012.12.015
In this report, a simple and label-free colorimetric assay was developed for detecting alkaline phosphatase (ALP). Based on the conjugated gold nanoparticle/adenosine triphosphate (AuNP/ATP) sensing system, this assay is highly sensitive and selective. In this system, ATP induces the aggregation of cetyltrimethylammonium bromide (CTAB)-capped AuNPs and ALP stimulates the disaggregation of AuNPs by converting ATP into adenosine through an enzymatic dephosphorylation reaction. Hence, the presence of ALP can be visually observed (gray-to-red color change) and monitored by the shift of the surface plasmon resonance (SPR) absorption band of AuNPs. Furthermore, the dynamic range of the method can be varied by addition of different metal ions (e.g. 100–600 unit/L to 5.0–100 unit/L and 0.2–20 unit/L in the presence of Ca2+ and Pb2+, respectively). The feasibility of this sensitive and specific assay with a tunable dynamic range was demonstrated to be consistent even in human serum samples.Highlights► Gold nanoparticle-based colorimetric assay was developed for alkaline phosphatase (ALP) detection. ► Tunable dynamic range over several orders of magnitude for ALP could be achieved by adding different metal ions. ► Feasibility of this method was demonstrated to be consistent even in human serum samples.
Co-reporter:Pu Zhang, Yi Wang, Yong Chang, Zu Hong Xiong, Cheng Zhi Huang
Biosensors and Bioelectronics 2013 Volume 49() pp:433-437
Publication Date(Web):15 November 2013
DOI:10.1016/j.bios.2013.05.056
•This method is simple, rapid, and highly selective for the detection of ppGpp.•The “off–on” fluorescent mode improves signal-to-background ratio and sensitivity.•Avoid the synthesis of complicated organic ligands for recognition of ppGpp.•Identified that functionalized-Ag NCs can be engineered as optical sensors.In this study, a facile strategy for highly selective and sensitive detection of bacterial alarmone, ppGpp, which is generated when bacteria face stress circumstances such as nutritional deprivation, has been established by developing an off–on fluorescent probe of Cu2+-mediated silver nanoclusters (Ag NCs). This work not only achieves highly selective detection of ppGpp in a broad range concentration of 2–200 μM, but also improves our understanding of the specific recognitions among DNA–Ag NCs, Cu2+, and ppGpp. The present strategy, together with other reports on the Ag NCs-related analytical methods, has also identified that Ag NCs functionalized with different molecules on their surfaces can be engineered fluorescent probes for a wide range of applications such as biosensing and bioimaging.
Co-reporter:Yue Liu;ChengZhi Huang
Science Bulletin 2013 Volume 58( Issue 17) pp:1969-1979
Publication Date(Web):2013 June
DOI:10.1007/s11434-013-5707-4
Single scattering particles, especially noble metal (plasmonic) nanoparticles, based analytical techniques are attractive recently and becoming the research focus of the light scattering analytical techniques. In this mini review, we summarize the single scattering particles based analytical techniques in the past decade including single scattering particles counting, single plasmonic nanoparticles sensing, and single plasmonic nanoparticles tracking/imaging. We emphasize the discussion on the single plasmonic nanoparticles sensing that combines with dark-field microscopy and resonant Rayleigh scattering spectroscopy.
Co-reporter:BoZhou Zou;Yue Liu;XiaoLi Yan;ChengZhi Huang
Science Bulletin 2013 Volume 58( Issue 17) pp:2027-2031
Publication Date(Web):2013 June
DOI:10.1007/s11434-013-5708-3
In this contribution, we developed a novel digital color analysis of gold nanoparticles (AuNPs) for pharmaceutical detection by choosing quinidine as an example. It was found that the color of AuNPs colloid solution changed from red to blue in the presence of different concentrations of quinidine, and the color information of each solution could be digitalized with tricolor (RGB) system. Under the optimum conditions, the R value of the solution was found to be linear with the natural logarithm of concentration of quinidine in the range of 112–384 nmol/L. This method has the advantages of rapid, economical and simple, and can serve as a potential alternative to traditional spectrophotometry for practical use.
Co-reporter:Li Jiao Liang, Cheng Zhi Huang
Talanta 2013 Volume 104() pp:198-203
Publication Date(Web):30 January 2013
DOI:10.1016/j.talanta.2012.11.010
Binding effect of guanosine triphosphate (GTP) with metal ions is involved in many biologically important processes, and so its investigation has been one interesting research focus for many chemical and biochemical research groups. In this contribution, we presented the unique fluorescence recovery and enhancement of GTP induced by Zn(II) based on the spectrofluorometric method. When excited at 280 nm, GTP is hardly fluorescent at the alkaline condition. However, the presence of Zn(II) caused an obvious fluorescence emission of GTP at 346 nm, and the binding molar ratio between GTP and Zn(II) had been proved to be 1. The investigations of binding property of various nucleotides with metal ions demonstrated that this fluorescence recovery and enhancement of GTP with Zn(II) was highly specific, which could successfully discriminate GTP from other structurally similar nucleotides including GDP and GMP. Furthermore, similar fluorescence response of the bacterial alarmone ppGpp to Zn(II) had also been identified.Highlights► The fluorescence response of GTP with Zn(II) was specific. ► Selectively fluorescent recognition of GTP could be established based on Zn(II). ► It was simplicity, rapid response and easy performance. ► It showed definite potential of zinc ions used for fluorescence sensing of ppGpp.
Co-reporter:Zhong De Liu, Hai Yan Zhu, Heng Xin Zhao, Cheng Zhi Huang
Talanta 2013 Volume 106() pp:255-260
Publication Date(Web):15 March 2013
DOI:10.1016/j.talanta.2012.10.079
The selective adsorption of single-stranded oligonucleotides (ssDNA) on gold nanoparticles (AuNPs) is well known for stabilizing the AuNPs against aggregation even at high salt concentrations. Our investigation shows that the non-crosslinking aggregation of arbitrary ssDNA-capped AuNPs occurs due to their interaction with the cationic polyamine, spermine (Spm), even without any addition of NaCl. The non-crosslinking aggregation mechanism is that the Spm, served as multivalent counterions, plays the dual roles of charge shielding and ion bridging among the ssDNA-capped AuNPs, which jointly result in the aggregation of the ssDNA-capped AuNPs. Therefore, a sensitive and highly selective colorimetric method for the detection of Spm was developed. To the best of our knowledge, it is the first successful case as to the efforts towards the development of optical assays for cationic polyamine, showing neither natural UV absorption nor fluorescence. Compared with the traditional methods of chromatography and capillary electrophoresis, the approach described here would provide a convenient alternative and new train of thought for the specific detection of Spm in both biological fluid and fermented products.Highlights► The aggregation of arbitrary ssDNA-capped AuNPs occurs when spermine was introduced. ► A highly selective colorimetric method for the detection of spermine was developed. ► It is the first successful case as to the efforts towards optical assay for spermine.
Co-reporter:Pu Zhang, Yi Wang, Fei Leng, Zu Hong Xiong, Cheng Zhi Huang
Talanta 2013 Volume 112() pp:117-122
Publication Date(Web):15 August 2013
DOI:10.1016/j.talanta.2013.03.013
► A simple and versatile approach for detecting organic small molecules.► Detection of coralyne with high sensitivity and selectivity.► Strong ability for analyzing coralyne in complicated matrix.In this contribution, an organic small molecule (OSM)-participating interaction between its aptamer and graphene oxide (GO) is investigated by taking coralyne as an example. Based on their interactions, a simple, rapid, highly sensitive and selective fluorometric method for the detection of coralyne is developed. GO can effectively quench the fluorescence of dye-labeled aptamer, while stronger binding of the aptamer and its target can make the fluorescence be recovered, which have been well demonstrated by the studies of the fluorescence spectra, fluorescence anisotropy, and circular dichroism spectra. In this case, the coralyne can be quantificationally detected by the variation of the fluorescence intensity, where GO acts as an efficient signal-to-background enhancer. With the increase of the coralyne, the fluorescence intensity increases gradually and linearly proportional to the concentration of the coralyne in the range of 10–700 nmol L−1. This method is reliable, and has been successfully applied for the detection of coralyne in complicated matrixes.
Co-reporter:Yue Liu and Cheng Zhi Huang
ACS Nano 2013 Volume 7(Issue 12) pp:11026
Publication Date(Web):November 26, 2013
DOI:10.1021/nn404694e
A comprehensive understanding of the growth mechanism of nanoalloys is beneficial in designing and synthesizing nanoalloys with precisely tailored properties to extend their applications. Herein, we present the investigation in this aspect by real-time monitoring of the in situ growth of single Ag@Hg nanoalloys, through direct amalgamation of Ag nanoparticles with elemental mercury, by dark-field scattering microscopy. Four typically shaped Ag nanoparticles, such as rods, triangular bipyramids, cubes, and spheres, were used as seeds for studying the growth of Ag@Hg nanoalloys. The scattered light of Ag nanoparticles of different shapes, on exposure to the growth solution, exhibited a noticeable blue-shift followed by a red-shift, suggesting the growth of Ag@Hg nanoalloys. The formation of Ag@Hg nanoalloys was confirmed by scanning electron microscopy, high-resolution transmit electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and elemental mapping and line scanning. Further analysis of the time-dependent spectral data and morphological change of single nanoparticles during the growth led to the visual identification of the growth mechanism of single Ag@Hg nanoalloys. Three important steps were involved: first, rapid adsorption of Hg atoms onto Ag nanoparticles; second, initial diffusion of Hg atoms into Ag nanoparticles, rounding or shortening the particles; third, further diffusion of Hg atoms leading to the formation of spherical Ag@Hg nanoalloys. On the basis of these results, Ag@Hg nanoalloys with given optical properties can be synthesized. Moreover, dark-field scattering microscopy is expected to be a powerful tool used for real-time monitoring of the in situ growth of other metal nanoparticles.Keywords: Ag@Hg nanoalloys; growth mechanism; light scattering; real-time monitoring; single nanoparticles
Co-reporter:Dong Mei Wang, Ming Xuan Gao, Peng Fei Gao, Hui Yang, and Cheng Zhi Huang
The Journal of Physical Chemistry C 2013 Volume 117(Issue 37) pp:19219-19225
Publication Date(Web):August 21, 2013
DOI:10.1021/jp404973b
The catalyzed luminol chemiluminescence (CL) in a strongly alkaline environment has been rarely induced by singlet oxygen (1O2). This paper reports that cetyltrimethyl ammonium bromide passivated carbon nanodots (CTAB-CDs), prepared by the hydrothermal treatment of fullerene in the presence of CTAB, can be used as excellent catalysts to dramatically enhance the CL intensity of the luminol–H2O2 system in NaOH medium owing to their unique surface property. More importantly, this CL enhancement takes place mainly through the intermediate of 1O2, which follows a different mechanism from traditional reports. The CL spectra, UV–vis spectra, electron paramagnetic resonance (EPR) spectra, transmission electron microscopy (TEM) images before and after the CL reaction, and the effects of various free radical scavengers on the CL intensity were conducted to identify the possible 1O2-participating CL enhancement mechanism. It was demonstrated that the CL enhancement by CTAB-CDs originated from the processes of the catalysis of CDs on the electron-transfer and the breakdown of H2O2. Both processes produced a great amount of 1O2 on the surface of CTAB-CDs, and then the reaction of 1O2 with luminol resulted in an unstable endoperoxide, which could rapidly decompose into the excited state 3-aminophthalate anions (3-APA*), leading to the enhanced CL at 440 nm. The important features of this CDs-catalyzed CL will not only enrich traditional luminol CL mechanism in strongly alkaline conditions but also open up a new route to study this novel carbon nanomaterial, which may broaden the applications in a large variety of fields.
Co-reporter:Wei Wang;Chun Liu;Jian Ling;ChengZhi Huang
Science China Chemistry 2013 Volume 56( Issue 6) pp:806-812
Publication Date(Web):2013 June
DOI:10.1007/s11426-012-4819-z
With the development of nanosciences, both localized surface plasmon resonance light scattering (LSPR-LS) and dynamic light scattering (DLS) techniques have been widely used for quantitative purposes with high sensitivity. In this contribution, we make a comparison of the two light scattering techniques by employing gold nanoparticles (AuNPs) aggregation induced by mercuric ions. It was found that citrate-stabilized AuNPs got aggregated in aqueous medium in the presence of mercuric ions through a chelation process, resulting in greatly enhanced LSPR-LS signals and increased hydrodynamic diameter. The enhanced LSPR-LS intensity (ΔI) is proportional to the concentration of mercuric ions in the range of 0.4–2.5 μM following the linear regression equation of ΔI = −84.7+516.4c, with the correlation coefficient of 0.983 (n = 6) and the limit of determination (3σ) about 0.10 μM. On the other hand, the increased hydrodynamic diameter can be identified by the DLS signals only with a concentration of Hg2+ in the range of 1.0–2.5 μM, and a linear relationship between the average hydrodynamic diameters of the resulted aggregates and the concentration of Hg2+ can be expressed as d = −6.16 + 45.9c with the correlation coefficient of 0.994. In such case, LSPR-LS signals were further applied to the selective determination of mercuric ions in lake water samples with high sensitivity and simple operation.
Co-reporter:XiJuan Zhao;JingMei Fang;YuanFang Li;ChengZhi Huang
Science China Chemistry 2013 Volume 56( Issue 11) pp:1651-1657
Publication Date(Web):2013 November
DOI:10.1007/s11426-013-4905-x
Selective recognition of adenosine 5′-triphosphate (ATP) is of great significance owing to its indispensable functions to organisms. Also, it is a challenging task because other nucleosides triphosphate hold the same triphosphate group and structurally planar bases as ATP. It is known that metal-organic frameworks (MOFs) are a new type of sensing material. In this work, highly selective recognition of ATP against other nucleosides triphosphate is successfully achieved with a luminescent MOF of [Zn(BDC)(H2O)2]n (BDC2− = 1,4-benzenedicarboxylate). [Zn(BDC)(H2O)2]n dispersed in water shows a remarkable redshift of the emission wavelength upon addition of ATP, while cytidine 5′-triphosphate (CTP), uridine 5′-triphosphate (UTP), and guanosine 5′-triphosphate (GTP), as well as some inorganic anions such as P2O74− or PO43− can’t induce such spectral change as ATP. 1H NMR, 31P NMR and Raman spectra indicate that both π-π stacking interactions and the coordination of Zn(II) with adenine and the phosphate group are involved in the interaction of [Zn(BDC)(H2O)2]n with ATP. In addition, the experimental results showed that the redshift extent of the emission wavelength of [Zn(BDC)(H2O)2]n has the linear relationship with the concentration of ATP in the range of 0.3–1.8 mmol/L. Based on this, the detection of ATP content in the sample of ATP injection was made with satisfactory results. This system pioneers the application of MOFs in the recognition of nucleotides, and testifies that the participation of base in the recognition process can improve the selectivity against the other nucleotides.
Co-reporter:ShuJun Zhen;FengLing Guo;YuanFang Li;ChengZhi Huang
Science China Chemistry 2013 Volume 56( Issue 3) pp:387-392
Publication Date(Web):2013 March
DOI:10.1007/s11426-012-4772-x
A biocompatible water-soluble dextran has been used for controllable one-dimensional assembly of gold nanoparticles via a one-pot method. Long gold nanoparticle chains with good dispersion in water could be easily obtained after adding dextran into the mixture of HAuCl4 and sodium citrate. The measurements of scanning electron microscopy (SEM) and dynamic light scattering (DLS) confirmed the formation of gold nanoparticle chains. The morphology and dispersion properties of gold nanoparticle chains could be tuned by adjustment of the reagent ratio, stirring speed, and reaction time.
Co-reporter:Li Qiang Chen, Sai Jin Xiao, Ping Ping Hu, Li Peng, Jun Ma, Ling Fei Luo, Yuan Fang Li, and Cheng Zhi Huang
Analytical Chemistry 2012 Volume 84(Issue 7) pp:3099
Publication Date(Web):February 27, 2012
DOI:10.1021/ac202810b
Although nanoparticles have been widely used as optical contrasts for cell imaging, the complicated prefunctionalized steps and low labeling efficiency of nanoprobes greatly inhibit their applications in cellular protein imaging. In this study, we developed a novel and general strategy that employs an aptamer not only as a recognizer for protein recognition but also as a linker for nanoreporter targeting to specifically label membrane proteins of interest and track their endocytic pathway. With this strategy, three kinds of nanoparticles, including gold nanoparticles, silver nanoparticles, and quantum dots (QDs), have been successfully targeted to the membrane proteins of interest, such as nucleolin or prion protein (PrPC). The following investigations on the subcellular distribution with fluorescent immunocolocalization assay indicated that PrPC–aptamer–QD complexes most likely internalized into cytoplasm through a classical clathrin-dependent/receptor-mediated pathway. Further single-particle tracking and trajectory analysis demonstrated that PrPC–aptamer–QD complexes exhibited a complex dynamic process, which involved three types of movements, including membrane diffusion, vesicle transportation, and confined diffusion, and all types of these movements were associated with distinct phases of PrPC endocytosis. Compared with traditional multilayer methods, our proposed aptamer-mediated strategy is simple in procedure, avoiding any complicated probe premodification and purification. In particular, the new double-color labeling strategy is unique and significant due to its superior advantages of targeting two signal reporters simultaneously in a single protein using only one aptamer. What is more important, we have constructed a general and versatile aptamer-mediated protein labeling nanoplatform that has shown great promise for future biomedical labeling and intracellular protein dynamic analysis.
Co-reporter:Jian Wang, Qing Zhang, Zhong De Liu and Cheng Zhi Huang
Analyst 2012 vol. 137(Issue 23) pp:5565-5570
Publication Date(Web):14 Sep 2012
DOI:10.1039/C2AN35952A
It is a challenge to detect molecules lacking a chromophore, such as polyamines, by optical methods since they are insensitive to light. In order to detect the optical signals, it is compulsory to derive these molecules with optical labels, which, however, is complicated, time-consuming and may be expensive. In this work, a highly specific strategy for spermine detection is developed on the basis of the iodide-induced conformational change of polythiophene. By using the triplex complex of negatively charged double-stranded calf thymus DNA (ctDNA)-stabilized cationic polythiophene as a fluorescent probe, the highly specific detection of spermine could be realized since polythiophene, which will be released from the triplex complex owing to the condensation and aggregation of ctDNA with spermine, undergoes a conformational change from the random-coiled non-planar state to the highly conjugated planar form in the presence of iodide, resulting in a yellow-to-red color conversion and fluorescence quenching. The quenched fluorescence was found to be proportional to the spermine concentrations in the range of 1.2–50 μM with the limit of detection (LOD) being 0.5 μM (3σ/k).
Co-reporter:Yue Liu and Cheng Zhi Huang
Analyst 2012 vol. 137(Issue 15) pp:3434-3436
Publication Date(Web):03 May 2012
DOI:10.1039/C2AN35167F
DNA–silver nanoparticle (AgNP) conjugates were facilely prepared through a one-step method, and then used for the quantitative detection of HIV DNA with a sandwich strategy based on their strong plasmon resonance scattering signals.
Co-reporter:Lei Zhan, Li Peng, Yan Yu, Shu Jun Zhen and Cheng Zhi Huang
Analyst 2012 vol. 137(Issue 21) pp:4968-4973
Publication Date(Web):28 Aug 2012
DOI:10.1039/C2AN35924C
The very simple and general spectrofluorometry of cellular prion protein (PrPC) is reported in this contribution based on the on–off noncovalent interaction of fluorescent dye-labelled PrPC DNA aptamers with multi-walled carbon nanotubes (MWCNTs). Due to the π–π stacking interaction between the DNA bases of the aptamer and the carbon nanotubes, the fluorescent dye and the MWCNTs are brought into close proximity, which leads to fluorescence quenching with a ratio of up to 87%. However, further addition of PrPC, which disturbs the π–π interaction owing to the strong and specific binding of the aptamer to PrPC, driving the aptamer away from the surface of the MWCNTs, restored the quenched fluorescence. This recovered fluorescence intensity was found to be in linear proportion to the PrPC concentration in the range of 8.2 to 81.7 nM, which builds the basis of the spectrofluorometry of the cellular prion protein.
Co-reporter:Li Jiao Liang, Shu Jun Zhen, Xi Juan Zhao and Cheng Zhi Huang
Analyst 2012 vol. 137(Issue 22) pp:5291-5296
Publication Date(Web):07 Sep 2012
DOI:10.1039/C2AN35743G
As one vital member among the family of phosphates, guanosine triphosphate (GTP) not only plays a very important role in many critical biological processes but also closely associates with definite pathological states. Based on the ratiometric fluorescence response of the zinc complex of 1,4-bis(imidazol-1-ylmethyl) benzene (bix) in this contribution, a highly selective recognition of GTP has been successfully developed. The fluorescence of bix–Zn(II) at 289 nm decreased in the presence of GTP with the appearance of one new emission band at 341 nm, resulting in ratiometric fluorescence changes with the concentration of GTP. With that, ratiometric fluorescence recognition for GTP could be effectively established, and so GTP could be successfully discriminated from other structurally similar anions, including ATP and PPi. Furthermore, bix–Zn(II) also has a ratiometric fluorescence response to DNA sequences containing guanine.
Co-reporter:Li Jiao Liang, Xi Juan Zhao and Cheng Zhi Huang
Analyst 2012 vol. 137(Issue 4) pp:953-958
Publication Date(Web):20 Dec 2011
DOI:10.1039/C2AN15845K
Pyrophosphate ion (PPi) is crucial in varieties of biological processes and industrial applications, and thus it is very important how to recognize it with high selectivity. In this contribution, one terpyridine (tpy)-based fluorescent molecule, 4-(methylphenyl)-2,2′:6′,2′′-terpyridine (mptpy), has been reported to display a highly selective recognition for PPi in the presence of Zn(II). After exposure toward the Zn(II) ion, the characteristic emission of mptpy at 376 nm red-shifted to 406 nm with a strong enhancement upon an excitation at 280 nm, and then blue-shifted to 388 nm with the further addition of PPi. Absorption and fluorescence measurements showed that other phosphates including phosphate (Pi) as well as nucleotide triphosphates could not induce the spectral changes similar to PPi, demonstrating the unique binding effect between mptpy-Zn(II) and PPi. This process could also discriminate PPi from other inorganic anions. Therefore, a tpy-based fluorescence method for the highly selective recognition of PPi could be developed.
Co-reporter:Yi Wang, Pu Zhang, Chun Fang Liu, Lei Zhan, Yuan Fang Li and Cheng Zhi Huang
RSC Advances 2012 vol. 2(Issue 6) pp:2322-2328
Publication Date(Web):26 Jan 2012
DOI:10.1039/C2RA00841F
An environmental friendly method for the preparation of functionalized reduced graphene oxide (rGO) in aqueous solution is developed with great easiness, using heparin as both a reducing agent and an effective stabilizer. Structural and morphological studies have demonstrated that part of the oxygen functionalities in the graphene oxide can be removed by this method, and heparin can be functionalized on the resulting rGO sheets through hydrophobic and hydrogen bonding interactions. The functionalized rGO shows good stability in aqueous solution, owing to the strong electrostatic and steric repulsions of the heparin which adsorb on the surfaces of rGO sheets. Moreover, the rGO exhibits excellent biocompatibility and anticoagulant activity, making it a promising candidate for widespread use in the biomedical field.
Co-reporter:Wen Dan Pu, Li Zhang and Cheng Zhi Huang
Analytical Methods 2012 vol. 4(Issue 6) pp:1662-1666
Publication Date(Web):28 Mar 2012
DOI:10.1039/C2AY25166C
Because of its rich π electrons, graphene oxide (GO) can bind with single-stranded DNA (ssDNA) through π-π stacking, but it cannot bind with double-stranded DNA (dsDNA). This different binding ability of GO with DNA has found many applications. By combining this ability with aptamer chemistry, we have developed a highly selective method for the detection of adenosine triphosphate (ATP). The hybrid of ATP aptamer with fluorescein (FAM)-labelled complementary DNA (FAM-DNA) demonstrates a weak affinity for GO and strong fluorescence of FAM-DNA. If ATP is present the strong fluorescence of FAM-DNA is quenched, because the binding of ATP with its aptamer greatly inhibits hybridization of the aptamer with FAM-DNA, and the unhybridized FAM-DNA is adsorbed on to the surface of GO. The quenched fluorescence intensity was found to be in proportion to the concentration of ATP in the range 3–320 μM with a detection limit of 0.45 μM. This method of ATP detection is highly selective and the existence of GTP, CTP and UTP have scarcely effect the determination.
Co-reporter:Sai Jin Xiao, Ping Ping Hu, Geng Fu Xiao, Yi Wang, Yue Liu, and Cheng Zhi Huang
The Journal of Physical Chemistry B 2012 Volume 116(Issue 32) pp:9565-9569
Publication Date(Web):July 23, 2012
DOI:10.1021/jp302522b
Though rapid tests were developed for mass screening of prion diseases in the last century, bovine spongiform encephalopathy (BSE) was still epidemic in some European countries. The main reason is that the sensitivity of such tests is insufficient for detecting animals that are incubating with prion diseases at the presymptomatic stage. Driven by this, in this contribution, we developed a novel sensitive label-free method taking advantage of DNA aptamer for prion proteins (PrP) detection through the formation of T-Hg2+-T configuration. In the presence of Hg2+ ions, double-strand structures formed due to the strong binding affinity of Hg2+ ions to the T bases of DNA aptamer, which dramatically enhanced the fluorescence of Syber Green I, a double-strand indicator. With the addition of prion protein, however, the specific interaction between prion protein and its aptamer forced the destruction of the double-strand structures, and thus the fluorescence of Syber Green I decreased. It was found that there is a linear relationship between the decreased fluorescence intensities and prion protein concentration ranging from 13.0 to 156.0 nmol/L. Compared with other methods, the method presented here holds the advantages of being label-free, rapid, highly sensitive, and selective, which shows great promise for clinical application.
Co-reporter:Dong Mei Wang, Yan Zhang, Lin Ling Zheng, Xiao Xi Yang, Yi Wang, and Cheng Zhi Huang
The Journal of Physical Chemistry C 2012 Volume 116(Issue 40) pp:21622-21628
Publication Date(Web):September 17, 2012
DOI:10.1021/jp306061u
Singlet oxygen (1O2) in the chemiluminescence (CL) of luminol has been rarely involved. In this work, graphene oxide (GO) was prepared and at first found to enhance the CL of luminol-H2O2 system in a weakly alkaline medium mainly through the intermediate of 1O2, which was greatly different from the traditional catalyst in such CL system that occurred in a strongly basic medium through the intermediates such as superoxide anion radical (O2·–) and hydroxyl radical (OH·). With the aid of CL spectral, UV–visible absorption spectral, and electron spin resonance (ESR) spectral measurements and investigations on the effects of various free radical scavengers on the GO-enhanced luminol CL, we identified the acceleration role of GO played in the electron-transfer processes and efficient catalysis on the decomposition of H2O2, generating a high yield of 1O2 on the surface of GO. The resulted 1O2 then reacted with luminol, producing an endoperoxide, which decomposed to the excited-state 3-aminophthalate anions (3-APA*), giving rise to light emission with the maximum wavelength at 440 nm. As a result, this 1O2-induced luminol CL, owing to the catalysis by GO, could have six-fold enhancement compared with that in the absence of GO. These investigations could be further extended to the use of GO as an amplified label for the CL determinations of H2O2 and glucose. The significant features of this GO-catalyzed luminol CL may open up new opportunities for its potential applications in a wide range of fields.
Co-reporter:Jian Wang, Guizhi Zhu, Mingxu You, Erqun Song, Mohammed Ibrahim Shukoor, Kejing Zhang, Meghan B. Altman, Yan Chen, Zhi Zhu, Cheng Zhi Huang, and Weihong Tan
ACS Nano 2012 Volume 6(Issue 6) pp:5070
Publication Date(Web):May 25, 2012
DOI:10.1021/nn300694v
An aptamer switch probe (ASP) linking chlorin e6 (Ce6), a photosensitizer molecule, to the surface of gold nanorods (AuNRs) was used to target cancer cells for photodynamic therapy (PDT) and photothermal therapy (PTT). In the presence of target cancer cells, the ASP changes conformation to drive Ce6 away from the gold surface, thereby producing singlet oxygen for PDT upon light irradiation. Since each AuNR is modified with many ASP-Ce6 molecules, the AuNR-ASP-Ce6 conjugate yields enhanced binding and therapeutic effect by the added ability to carry many photosensitizers. In addition, absorption of radiation by the gold nanorods enables further cell destruction by the photothermal effect. Consequently, this multimodal AuNR-ASP-Ce6 conjugate offers a remarkably improved and synergistic therapeutic effect compared to PTT or PDT alone, providing high specificity and therapeutic efficiency, which can be generalized to other types of cancer therapies.Keywords: aptamer switch probe; cancer therapy; gold nanorods; photosensitizer
Co-reporter:Jian Wang, Pu Zhang, Chun Mei Li, Yuan Fang Li, Cheng Zhi Huang
Biosensors and Bioelectronics 2012 Volume 34(Issue 1) pp:197-201
Publication Date(Web):15 April 2012
DOI:10.1016/j.bios.2012.02.001
In this contribution, a simple, rapid, colorimeteric and selective assay for lysine was achieved by a controllable end-to-end assembly of gold nanorods (AuNRs) in the presence of Eu3+ and lysine. This one-pot end-to-end assembly of 11-mercaptoundecanoic acid (MUA) modified AuNRs was occurred in Britton–Robinson buffer of pH 6.0, which involves the coordination binding between Eu3+ and COO− groups as well as the electrostatic interaction of the COO− groups of MUA with the NH3+ group of lysine. As monitored by absorption spectra, scanning electron microscopic (SEM) images and dynamic light scattering (DLS) measurement, the end-to-end chain assembly results in large red-shift in the longitudinal plasmon resonance absorption (LPRA), giving red-to-blue color change of AuNRs. Importantly, it was found that the red-shift of LPRA is linearly proportional to the concentrations of lysine in the range of 5.0 × 10−6–1.0 × 10−3 M with the limit of detection (LOD) being 1.6 × 10−6 M (3σ/k). This red-shift of LPRA is highly selective, making it possible to develop a rapid, selective and visual assay for lysine in food samples.Highlights► An end-to-end assembly of gold nanorods was made. ► The assembly involves coordination and electrostatic interaction. ► The red-shift in longitudinal absorption of AuNRs is highly selective for lysine.
Co-reporter:Xi Juan Zhao, Lin He, Cheng Zhi Huang
Talanta 2012 Volume 101() pp:59-63
Publication Date(Web):15 November 2012
DOI:10.1016/j.talanta.2012.08.046
Pyrophosphate (PPi), as a biologically related phosphate anion, plays very important roles in organisms. Here, a highly selective visual method for distinction of PPi was made with commercial available 4-[(5-chloro-2-pyridyl)azo]-1,3-diaminobenzene (5-Cl-PADAB) in the presence of copper(II). The yellow solution of 5-Cl-PADAB exhibits strong absorption at 450.5 nm, and addition of Cu(II) results in a red solution with a new absorption band at 506.0 nm. Upon titration with PPi, the absorption band at 506.0 nm decreases with blueshift, while another new absorption band in the region from 562.0 nm to 750.0 nm appears which gradually splits into two peaks, and the color accordingly changes from red to cyan. Further addition of PPi, the new absorption peaks gradually disappear, and the mixture shows the absorption of 5-Cl-PADAB and recovers to yellow from cyan. This process is highly selective for PPi since other phosphate anions such as nucleotides cannot induce such spectral and color changes. With this method, the detection of PPi concentration in human urine was made with satisfactory results.Highlights► This method needs no complicated modification and organic synthesis. ► This recognition process for PPi has a dramatic color change from red to cyan. ► We can visually detect PPi with naked eyes. ► This method has good selectivity for PPi against other anions such as nucleotides.
Co-reporter:Shu Jun Zhen, Feng Ling Guo, Li Qiang Chen, Yuan Fang Li, Qing Zhang and Cheng Zhi Huang
Chemical Communications 2011 vol. 47(Issue 9) pp:2562-2564
Publication Date(Web):04 Jan 2011
DOI:10.1039/C0CC03205K
A novel type of leaf-like poly (p-phenylenediamine) (PpPD) microcrystal was prepared under mild conditions, which was successfully applied to the visual detection of Co2+in vitro and in tissue based on the extinction and light scattering features owing to the special etching effect of Co2+ on the surface of the leaf-like microcrystal.
Co-reporter:Heng Xin Zhao, Li Qin Liu, Zhong De Liu, Yi Wang, Xi Juan Zhao and Cheng Zhi Huang
Chemical Communications 2011 vol. 47(Issue 9) pp:2604-2606
Publication Date(Web):13 Jan 2011
DOI:10.1039/C0CC04399K
A simple method for phosphate (Pi) detection is established by developing an off–on fluorescence probe of europium-adjusted carbon dots (CDs), which has been successfully applied to the detection of Pi in very complicated matrixes such as artificial wetlands system.
Co-reporter:Yue Liu, Jian Ling and Cheng Zhi Huang
Chemical Communications 2011 vol. 47(Issue 28) pp:8121-8123
Publication Date(Web):20 Jun 2011
DOI:10.1039/C1CC11503K
Colors of scattering light of single gold nanoparticles (AuNPs) were coded with the tricolor (RGB) system by assigning digital values to R, G and B and then this was applied to binding studies of thiols to AuNPs through RGB analysis.
Co-reporter:Yan Zhang, Yue Liu, Shu Jun Zhen and Cheng Zhi Huang
Chemical Communications 2011 vol. 47(Issue 42) pp:11718-11720
Publication Date(Web):27 Sep 2011
DOI:10.1039/C1CC14491J
A long range resonance energy transfer (LrRET) strategy for label-free and sensitive DNA detection is outlined by introducing graphene oxide (GO) as an efficient signal-to-background enhancer, giving a limit of determination (3σ) of 0.31 nM.
Co-reporter:Yi Juan Long, Yuan Fang Li, Yue Liu, Jia Jia Zheng, Jie Tang and Cheng Zhi Huang
Chemical Communications 2011 vol. 47(Issue 43) pp:11939-11941
Publication Date(Web):05 Oct 2011
DOI:10.1039/C1CC14294A
Mercury-stimulated peroxidase mimetic activity of gold nanoparticles was presented, with which a sensitive label-free colorimetric method for Hg2+ was developed.
Co-reporter:Zhong De Liu, Ping Ping Hu, Heng Xin Zhao, Yuan Fang Li, Cheng Zhi Huang
Analytica Chimica Acta 2011 Volume 706(Issue 1) pp:171-175
Publication Date(Web):7 November 2011
DOI:10.1016/j.aca.2011.08.032
Carbon nanotubes (CNTs) can efficiently quench the fluorescence of the adsorbed fluorophores and nonconvalently interact with soft single-stranded DNA (ssDNA). Upon disruption of CNTs–fluorescent oligonucleotides hybrid by nuclease S1, fluorescence turn-on was observed. Using this strategy, a platform based on fluorescence signal for monitoring the activity of nuclease with advantages of high sensitivity and commonality was established, and a linear relationship between initial cleavage reaction rate and nuclease S1 concentration is found in the range of 0.6–8.0 U mL−1 with a detection limit of 0.08 U mL−1. Furthermore, by taking pyrophosphate as an example, we use the assay to evaluate the prohibition effect on nuclease, and the extent of fluorescence recovery decreased linearly with increasing the concentration of pyrophosphate in the range of 0.2–1.4 mM, implying that the cleavage reaction by nuclease S1 was prohibited, and therefore this fluorescence assay can also be conveniently utilized for inhibitor screening of nuclease.Graphical abstractA versatile platform for monitoring the activity of nuclease and screening of its inhibitor with a fluorescence off–on–off strategy.Highlights► A self-assembled energy transfer-based quenching system was constructed. ► It can be utilized for activity monitoring and inhibitor screening of nuclease. ► The strategy has the advantages of high sensitivity and commonality.
Co-reporter:Yi Wang ; Shu Jun Zhen ; Yan Zhang ; Yuan Fang Li
The Journal of Physical Chemistry C 2011 Volume 115(Issue 26) pp:12815-12821
Publication Date(Web):June 2, 2011
DOI:10.1021/jp202886q
With unique structure and extraordinary properties, graphene has attracted tremendous attention in a wide range of fields recently. In terms of its biomedical applications, graphene has been used to be biosensors and drug carriers, including in vitro and in vivo studies. Therefore, how to clarify the behaviors of graphene in organism is a significant and long-term challenge. For that purpose, fabricating graphene-based materials which can give off some measurable signals become a fascinating topic. In this study, we report a facile noncovalent strategy to fabricate metal nanoparticle/graphene oxide (MNP/GO) hybrids, which can be used to directly illuminate graphene for optical imaging by employing the strong localized surface plasmon resonance (LSPR) light scattering of MNPs as an effective signal reporter, and thus the profiles of graphene can be observed with a dark-field microscope. The formation of MNP/GO hybrids has been confirmed successfully, and these new nanocomposites assembled from individual building blocks can be promising candidates for the applied purposes of biological imaging, drug delivery, and cancer therapy owing to their collective properties.
Co-reporter:Jian Wang, Qing Zhang, Ke Jun Tan, Yun Fei Long, Jian Ling, and Cheng Zhi Huang
The Journal of Physical Chemistry B 2011 Volume 115(Issue 7) pp:1693-1697
Publication Date(Web):February 2, 2011
DOI:10.1021/jp107099z
Investigation on compaction and decompaction of polymers is very important since it is a fundamental problem in polymer physics. With the aids of atomic force microscope (AFM) and dynamic light scattering (DLS) measurements in this contribution, the temperature-dependent compaction/decompaction transition process of water-soluble cationic polythiophene (PT) was investigated in the presence of KI. The above process is characterized by the red-to-yellow color change and fluorescence recovery and is reversible during the heating−cooling cycles in the range from 25 to 55 °C, indicating that the compaction and decompaction of polymer can be employed as a temperature indicator.
Co-reporter:Xi Juan Zhao, Cheng Zhi Huang
Biosensors and Bioelectronics 2011 30(1) pp: 282-286
Publication Date(Web):
DOI:10.1016/j.bios.2011.09.028
Co-reporter:LiQin Liu;YuanFang Li;Lei Zhan;Yue Liu;ChengZhi Huang
Science China Chemistry 2011 Volume 54( Issue 8) pp:
Publication Date(Web):2011 August
DOI:10.1007/s11426-011-4351-6
Carbon dots (CDs) with average diameter of 3.1 ± 0.5 nm were facilely synthesized with candle soot through hydrothermal reaction in sodium hydroxide aqueous solution. The as-prepared CDs were covered with a lot of hydroxyls, possessed properties of good water-solubility, anti-photobleaching, salt tolerance, and low cytotoxicity, and had a fluorescence quantum yield (QY) of about 5.5%. The fluorescence of the hydroxyls-coated CDs could be selectively quenched by metal ions such as Cr3+, Al3+ and Fe3+, which is because these metals can easily combine with the hydroxyl groups on the surface of CDs and induce aggregation of hydroxyls-coated CDs. Experiments showed that the quenching of Cr3+ had a Sterm-Volmer constant of 1.03 × 107 M−1 with a liner range of 1.0–25.0 μM and detection limit of 60 nM (3 σ).
Co-reporter:Yi Wang, Yuan Fang Li, Jian Wang, You Sang and Cheng Zhi Huang
Chemical Communications 2010 vol. 46(Issue 8) pp:1332-1334
Publication Date(Web):06 Jan 2010
DOI:10.1039/B921464J
We report a novel, simple, highly selective and versatile approach for the end-to-end assembly of gold nanorods (GNRs) by means of the specific molecular recognition between thymine-rich (T-rich) oligonucleotides and mercury(II).
Co-reporter:Li Zhang, Shu Jun Zhen, You Sang, Jing Yun Li, Yi Wang, Lei Zhan, Li Peng, Jian Wang, Yuan Fang Li and Cheng Zhi Huang
Chemical Communications 2010 vol. 46(Issue 24) pp:4303-4305
Publication Date(Web):06 May 2010
DOI:10.1039/C0CC00231C
We report a novel strategy to fabricate metal nanoparticle/carbon nanotube hybrids with unique plasmon properties as well as biocompatibility and further apply them as efficient dark field light scattering agents for cancer cell imaging.
Co-reporter:Wen Jing Qi, Di Wu, Jian Ling and Cheng Zhi Huang
Chemical Communications 2010 vol. 46(Issue 27) pp:4893-4895
Publication Date(Web):11 Jun 2010
DOI:10.1039/C0CC00886A
Melamine can be sensitively detected in aqueous medium through its selective interaction with polythymine (polyTn) modified gold nanoparticles (AuNPs) by forming triple H-bonds, which results in aggregation of the polyTn-stabilized AuNPs, displaying variations of localized plasmon resonance features such as colour change from red to purple and enhanced localized surface plasmon resonance light scattering (LSPR-LS) signals.
Co-reporter:Ping Ping Hu, Li Qiang Chen, Chun Liu, Shu Jun Zhen, Sai Jin Xiao, Li Peng, Yuan Fang Li and Cheng Zhi Huang
Chemical Communications 2010 vol. 46(Issue 43) pp:8285-8287
Publication Date(Web):30 Sep 2010
DOI:10.1039/C0CC02600J
An ultra-sensitive detection strategy for prion protein is proposed based on the long range resonance energy transfer (LrRET) from quantum dots (QDs) to the surface of gold nanoparticles (AuNPs), in which process energy donor–acceptor separation distance ranges from 9 to 22 nm.
Co-reporter:Sai Jin Xiao, Ping Ping Hu, Xiao Dong Wu, Yan Li Zou, Li Qiang Chen, Li Peng, Jian Ling, Shu Jun Zhen, Lei Zhan, Yuan Fang Li, and Cheng Zhi Huang
Analytical Chemistry 2010 Volume 82(Issue 23) pp:9736
Publication Date(Web):November 1, 2010
DOI:10.1021/ac101865s
The major challenge of prion disease diagnosis at the presymptomatic stage is how to sensitively or selectively discriminate and detect the minute quantity of disease-associated prion protein isoform (PrPRes) in complex biological systems such as serum and brain homogenate. In this contribution, we developed a dual-aptamer strategy by taking the advantages of aptamers, the excellent separation ability of magnetic microparticles (MMPs), and the high fluorescence emission features of quantum dots (QDs). Two aptamers (Apt1 and Apt2), which can recognize their two corresponding distinct epitopes of prion proteins (PrP), were coupled to the surfaces of MMPs and QDs, respectively, to make MMPs-Apt1 and QDs-Apt2 ready at first, which then could be coassociated together through the specific recognitions of the two aptamers with their two corresponding distinct epitopes of PrP, forming a sandwich structure of MMPs-Apt1-PrP-Apt2-QDs and displaying the strong fluorescence of QDs. Owing to the different binding affinities of the two aptamers with PrPRes and cellular prion protein (PrPC), both of which have distinct denaturing detergent resistance, our dual-aptamer strategy could be applied to discriminate PrPRes and PrPC successfully in serum. Further identifications showed that the present dual-aptamer assay could be successfully applied to the detection of PrP in 0.01% brain homogenate, about 1000-fold lower than that of commonly applied antibody-mediated assays, which can detect PrP just in 10% brain homogenate, indicating that the present designed dual-aptamer assay is highly sensitive and adequate for clinical diagnosis without isolation of target protein prior to assay.
Co-reporter:Shu Jun Zhen, Li Qiang Chen, Sai Jin Xiao, Yuan Fang Li, Ping Ping Hu, Lei Zhan, Li Peng, Er Qun Song, and Cheng Zhi Huang
Analytical Chemistry 2010 Volume 82(Issue 20) pp:8432
Publication Date(Web):September 20, 2010
DOI:10.1021/ac100709s
Although holding the advantages of both an aptamer and a molecular beacon (MB), a molecular aptamer beacon (MAB) needs complicated and expensive modifications at both of its ends and usually has a high background signal because of the low energy transfer efficiency between the donor and the acceptor. To overcome these shortcomings, in this study, we develop a long-range resonance energy transfer (LrRET) system by separating the donor from the acceptor, wherein only one end of the MAB is fluorescently labeled and acts as the energy donor and multiwalled carbon nanotubes (MWCNTs) are introduced as the energy acceptor. To test the feasibility of the newly designed MAB system, adenosine triphosphate (ATP) has been employed as a proof-of-concept target. It is found that the fluorescence of the designed MAB is completely quenched by MWCNTs, supplying a very low background signal. Then the quenched fluorescence is recovered significantly with the addition of ATP, so that ATP can be detected in the range of 0.8−80 μM with a limit of detection of 0.5 μM (3σ). Compared with the conventional fluorescence resonance energy transfer, the efficiency of LrRET between the dye and MWCNTs is much higher. Since only one end of the MAB needs the modification, the present strategy is simple and cost-effective. Furthermore, the use of MWCNTs can greatly reduce the fluorescence background of the MAB and supply a high sensitivity, showing its generality for detection of a variety of targets.
Co-reporter:You Sang, Li Zhang, Yuan Fang Li, Li Qiang Chen, Jia Li Xu, Cheng Zhi Huang
Analytica Chimica Acta 2010 Volume 659(1–2) pp:224-228
Publication Date(Web):5 February 2010
DOI:10.1016/j.aca.2009.11.031
Nowadays, hydrogen peroxide (H2O2) has attracted more and more attentions in biochemical fields owing to its important role in biological systems. In this contribution, we propose a novel assay for the detection of H2O2 based on the cleavage of ssDNA on gold nanoparticles (AuNPs). It was known that AuNPs could be stable in the presence of single-stranded DNA (ssDNA) which prevents the salt-induced aggregation of AuNPs in solution owing to the electrostatic repulsion. However, hydroxyl radical (HO) generated from Fenton reaction could cleave the ssDNA and induce the aggregation of AuNPs. Therefore, color change from red to blue owing to the plasmon resonance absorption (PRA) of AuNPs can be observed by the naked eyes and enhancement of plasmon resonance light scattering could be measured with a common spectrofluorometer. The values of A650/A520 of the PRA band were found to be linearly proportional to the concentration of H2O2 in the range of 2.0 × 10−7 to 8.0 × 10−6 mol L−1 with the limit of determination (LOD) being 40 nmol L−1 (S/N = 3), and thus the content of H2O2 in rat encephalon extraction could be successfully detected with the recovery in the range of 98–103%.
Co-reporter:Xijuan Zhao and Cheng Zhi Huang
Analyst 2010 vol. 135(Issue 11) pp:2853-2857
Publication Date(Web):28 Sep 2010
DOI:10.1039/C0AN00431F
Pyrophosphate (PPi) participates in many biological and chemical processes such as energy transduction so that investigations on its role and detection have become very significant. In this contribution, we have developed a molecular logic gate for the recognition of PPi with a fluorescent hypocrellin A-zinc(II) complex (HA-Zn2+), and the outputs of which correspond to the fluorescence emission ratio at 604 nm and wavelength shift relative to 629 nm. The emission at 604 nm is the intrinsic fluorescence of HA, which can be effectively quenched by Zn2+ with a new emission at 629 nm owing to the formation of the HA-Zn2+ complex. It was found, however, that the new emission at 629 nm is highly selectively quenched with the addition of PPi, recovering the emission at 604 nm, and the recovery ratio is linearly correlated with PPi in the range of 1.8 × 10−5 mol L−1 to 2.4 × 10−4 mol L−1. ATP, UTP, CTP, GTP, GDP and GMP cannot demonstrate the same spectral actions as PPi. Since the inputs of PPi and the phosphate anions obtain different logical outputs, the designed logic gates have good selectivity and can distinguish PPi from the other anions.
Co-reporter:Jian Ling and Cheng Zhi Huang
Analytical Methods 2010 vol. 2(Issue 10) pp:1439-1447
Publication Date(Web):17 Sep 2010
DOI:10.1039/C0AY00452A
Gold nanoparticles (AuNPs) are the most interesting nanomaterials for analytical purposes owing to their unique optical and electrochemical properties resulting from the localized surface plasmon resonance (LSPR) of the electrons, displaying strong absorption and scattering of light from visible to near-infrared region by tuning the particles sizes and shapes. In fluorescence resonance energy transfer (FRET) process, AuNPs have been identified to act as excellent acceptors to replace traditional organic quenchers. Starting from quenching advantages of AuNPs in FRET system and energy transfer mechanism of donor to AuNPs, herein we try to summarize and discuss typical AuNPs based FRET methods in terms of DNA hybridizations, immunoreactions, specific molecular bindings or adsorptions, and provide their analytical applications in biochemical and pharmaceutical analysis.
Co-reporter:Yi Wang, Lei Zhan and Cheng Zhi Huang
Analytical Methods 2010 vol. 2(Issue 12) pp:1982-1988
Publication Date(Web):13 Oct 2010
DOI:10.1039/C0AY00470G
We present a room-temperature strategy for the preparation of dextran-capped gold nanoparticles (AuNPs) in this contribution by employing dextran, which acts as both a reducing agent and a stabilizer, and thus well dispersed, uniform and biocompatible AuNPs could be successfully prepared in one pot. The investigations, including toxicological effect on cells and the capability of resisting aggregation in high ion medium, have demonstrated that the as-prepared AuNPs are biocompatible and stable even if in a medium of high ionic strength. In order to identify the practicability of the dextran-capped AuNPs, colorimetric detection of dihydralazine sulfate (DHZS) in uric samples based on the localized surface plasmon resonance (LSPR) of the AuNPs is made with the recovery in the range of 98.3–102.5%.
Co-reporter:Li Qiang Chen, Sai Jin Xiao, Li Peng, Tong Wu, Jian Ling, Yuan Fang Li and Cheng Zhi Huang
The Journal of Physical Chemistry B 2010 Volume 114(Issue 10) pp:3655-3659
Publication Date(Web):January 29, 2010
DOI:10.1021/jp9104618
Aptamer-adapted silver nanoparticles (Apt-AgNPs) were developed as a novel optical probe for simultaneous intracellular protein imaging and single nanoparticle spectral analysis, wherein AgNPs act as an illuminophore and the aptamer as a biomolecule specific recognition unit, respectively. It was found that streptavidin-conjugated and aptamer-functionalized AgNPs show satisfactory biocompatibility and stability in cell culture medium, and thus not only can act as a high contrast imaging agent for both dark-field light scattering microscope and TEM imaging but also can inspire supersensitive single nanoparticle spectra for potential intercellular microenvironment analysis. Further investigations showed that caveolae-related endocytosis is likely a necessary pathway for Apt-AgNPs labeled PrPc internalization in human bone marrow neuroblastoma cells (SK-N-SH cells). The integrated capability of Apt-AgNPs to be used as light scattering and TEM imaging agents, along with their potential use for single nanoparticle spectral analysis, makes them a great promise for future biomedical imaging and disease diagnosis.
Co-reporter:Wen Jing Qi, Cheng Zhi Huang, Li Qiang Chen
Talanta 2010 Volume 80(Issue 3) pp:1400-1405
Publication Date(Web):January 2010
DOI:10.1016/j.talanta.2009.09.042
A facile solution-phase synthesis route of highly uniform Cu2O nanospheres (Cu2O NPs) with the size of 57.7 ± 4.7 nm was developed, and then the nanoparticles were applied to live cell imaging under a common dark-field microscope. Starting from copper(II) salts, the synthesis of Cu2O NPs was made in the presence of cetyltrimethylammonium bromide (CTAB) by reducing the copper(II) with sodium borohydride (NaBH4) in aqueous medium and by aging process in the air. Monitoring of morphology evolution process of Cu2O NPs with scanning electron microscopy (SEM) and measuring of the UV–visible spectra showed that the synthesis of Cu2O NPs follows the reduction–oxidation coupled process of Cu2+ into Cu0 species at first and then the resulted Cu0 species into Cu2O NPs in the air. Light scattering (LS) features have been measured with a common spectrofluorometer and a common dark-field microscope, and it was found that the as-prepared Cu2O NPs display strong blue scattering light and can be applied for cell imaging. If incubated with human bone marrow neuroblastoma, transferrin-conjugated Cu2O NPs can get into the cells and show strong pure blue light in cytoplasm. Further investigations showed that the Cu2O NPs could be applied for probes for conformation of proteins.
Co-reporter:Chun Mei Li, Yuan Fang Li, Jian Wang, Cheng Zhi Huang
Talanta 2010 Volume 81(4–5) pp:1339-1345
Publication Date(Web):15 June 2010
DOI:10.1016/j.talanta.2010.02.032
With the aids of localized plasmon resonance absorption and light-scattering measurements in this contribution, we investigated the aggregation of cetyltrimethylammonium bromide (CTAB) capped gold nanoparticles (AuNPs) in the presence of adenosine triphosphate (ATP). It was found that gradual aggregation of AuNPs occurs under physiological conditions with increasing ATP concentration from 200.0 to 400.0 μM, but the aggregates get dispersed again with much more increase of ATP concentration than 800.0 μM, corresponding with the color change from red to blue and to red again. Mechanism investigations showed that the aggregation of the AuNPs is likely induced by two interaction modes. One is the electrostatic interaction between the phosphate anions associated with the ATP and AuNPs owing to the cationic surfactant on the surfaces of AuNPs, and the other is the interaction between gold atom and nitrogen-containing bases. Further investigations showed that this aggregation mechanism could extend to the interactions between positively charged AuNPs with other analogs of ATP, such as guanosine triphosphate (GTP) and cytidine triphosphate (CTP).
Co-reporter:PingPing Hu;Li Peng;ShuJun Zhen;LiQiang Chen;SaiJin Xiao
Science China Chemistry 2010 Volume 53( Issue 4) pp:792-796
Publication Date(Web):2010 April
DOI:10.1007/s11426-010-0128-6
Homochirality in life has always been a driving force in scientific research and natural exploration. It has not been satisfactorily explained, and systematic investigations are necessary. This paper reported a homochiral expression of proteins dependent on the stirring direction of growing media. By controlling the stirring direction clockwise (CW) and anticlockwise (ACW) of the culture medium, proteins with distinct secondary structures were obtained, and D-amino acid may be included in the protein cultured with the stirring direction of ACW. Considering the effect of force fields, which might affect the process of folding and refolding of cellular protein in this report, the control of force fields might be a good way to prepare asymmetric drugs, and the rotational direction of the earth is possibly related to the chirality in primitive life molecules.
Co-reporter:Jian Ling, Yuan Fang Li and Cheng Zhi Huang
Analytical Chemistry 2009 Volume 81(Issue 4) pp:1707
Publication Date(Web):January 27, 2009
DOI:10.1021/ac802152b
In this contribution, we established a sandwich immunoassay system with a common spectrofluorometer to collect the plasmon resonance scattering (PRS) signals from silver nanoparticles (AgNPs) immunotargeted on glass slides. By taking the immunoreactions of goat antihuman IgG (Fc fragment specific) antibody (GAH-IgG), human immunoglobulin (H-IgG), and rabbit antihuman IgG (Fab fragment specific) antibody (RAH-IgG) as an example, we found that if a primary antibody (GAH-IgG) was first immobilized on the surface of glass slides and applied to capture target antigen (H-IgG), AgNPs-labeled secondary antibody (RAH-IgG) could be employed to detect the target antigen (H-IgG) by forming a sandwich immune complex on the surface of the glass slide. It was found that the PRS signals resulting from the AgNPs immunotargeted on the glass slides could be applied to the quantitative detection of H-IgG target antigen in the range of 10−1000 ng/mL with the limit of determination of 1.46 ng/mL (3σ) under optimal conditions, which is sensitive and comparable with reported chemiluminescence immunoassays. With a dark-field microscope coupled with a spectral system, we measured the PRS features of single AgNPs immunotargeted on the glass slides, showing that the PRS of single nanoparticles might have potential applications in analytical chemistry. Further findings showed that the strong PRS signals from the AgNPs immunotargeted on the glass slides can be clearly seen and distinguished by naked eyes under the excitation of a common white light-emitting diode (LED) torch. Therefore, a visual PRS immunoassay system can be established easily with common glass slides and an LED torch.
Co-reporter:Zhong De Liu, Yuan Fang Li, Jian Ling and Cheng Zhi Huang
Environmental Science & Technology 2009 Volume 43(Issue 13) pp:5022
Publication Date(Web):May 21, 2009
DOI:10.1021/es9001983
It is known that localized surface plasmon resonance (LSPR) is responsible for the surface-enhanced spectroscopic processes of metallic nanoparticles and thus LSPR spectroscopy has become a powerful technique for chemical and biological purposes. In this contribution, we present a simple homogeneous Hg2+ assay by measuring enhanced LSPR scattering signals resulted from Hg2+−DNA complex induced aggregation of gold nanoparticles (AuNPs). In a medium of pH 7.4 tris-HCl buffer containing 0.05 M NaCl, single-stranded oligonucletides with the sequence of 5′-d(T6)-3′ (poly-T6 ssDNA), can be selectively adsorbed onto the surface of gold colloids, stabilizing the AuNPs against aggregation. If Hg2+−DNA complex via Hg2+-mediated thymine-Hg2+-thymine (T-Hg2+-T) is formed, however, the adsorption of poly-T6 ssDNA onto the surface of gold colloids gets reduced, and then aggregation of the AuNPs occurs owing to the decrease of the electrostatic repulsion between AuNPs. Consequently, strong LSPR scattering signals resulting from the aggregates of AuNPs could be visually observed under a dark field microscope and easily be measured with a common spectrofluorometer. The LSPR scattering intensities characterized at 556.0 nm were found to be proportional to the concentration of Hg2+ ions in the range of 4.0 × 10−8 to 6.0 × 10−7 M with the limit of determination (3σ) of 1.0 nM. Compared with reported colorimetric methods, our present approaches display the advantages of higher sensitivity.
Co-reporter:Li Zhang, Cheng Zhi Huang, Yuan Fang Li and Qing Li
Crystal Growth & Design 2009 Volume 9(Issue 7) pp:3211
Publication Date(Web):June 2, 2009
DOI:10.1021/cg801265y
In this contribution, a general one-step route to synthesize Au crystals with the shape of twinned tabular crystals, single-crystalline nanoplates, and multitwinned decahedra is proposed. By employing HAuCl4 in an aqueous medium as the oxidizing reagent, tetracycline hydrochloride as the reducing agent, and cetyltrimethylammonium bromide (CTAB) as the capping agent, we found it is very easy to get the three types of Au crystals by modulating the molar ratio of CTAB with HAuCl4. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high-resolution TEM (HRTEM) have been employed to characterize the three types of symmetric morphologies. Further investigations involve side-face analysis and growth mechanism of Au twinned tabular crystals, and the optical properties of the obtained crystals. Absorption and dark field light scattering images demonstrate their potential applications in cancer cell diagnostics and photothermal therapy. Moreover, a tentative explanation for the growth mechanism of Au crystals with different morphologies has been made.
Co-reporter:Tong Wu, Yuan Fang Li, Cheng Zhi Huang
Chinese Chemical Letters 2009 Volume 20(Issue 5) pp:611-614
Publication Date(Web):May 2009
DOI:10.1016/j.cclet.2009.01.024
Triangular silver nanoprisms were prepared and applied to make colorimetric detection of cysteine based on our findings that cysteine could lead to the blue shift of the dipole plasmon resonance absorption, but other 19 kinds of natural amino acids could not. Cysteine with a concentration 160 nmol/L can result in a color change that can be discerned with naked eyes.
Co-reporter:Chun Mei Li, Yuan Fang Li, Cheng Zhi Huang, Yun Fei Long
Talanta 2009 Volume 78(Issue 3) pp:1173-1176
Publication Date(Web):15 May 2009
DOI:10.1016/j.talanta.2009.01.041
A visual test paper by taking common filter paper as solid support for extremely strong concentrated acidity has been developed in this contribution with a new synthesized isoindole compound starting from p-phenylenediamine and the coupled fluorogenic reagent of o-phthaldialdehyde-β-mercaptoethanol. It was very easy for semiquantitative detection of acidity in the range of 0.2–18 M ([H+]) in extreme acidic solution based on the color changes of the solution or the visual test paper prepared by immerging filter paper slides into the solution of the new synthesized reagent. Quantitative detection of concentrated strong acids could be successfully constructed through the linear relationship exists between the absorbance of the chromogenic reagent at 510 nm and the acid concentrations.
Co-reporter:Sai Jin Xiao, Ping Ping Hu, Yuan Fang Li, Cheng Zhi Huang, Tao Huang, Geng Fu Xiao
Talanta 2009 Volume 79(Issue 5) pp:1283-1286
Publication Date(Web):15 October 2009
DOI:10.1016/j.talanta.2009.05.040
An aptamer-participated haprin structure was designed by employing cellular prion protein (PrPC) as a model protein, and thus an aptamer-mediated turn-on fluorescence assay for proteins was developed in this contribution. The designed aptamer-participated haprin structure consists of three segments. Namely, an aptamer sequence located in the loop, three guanine bases at 3′-terminal, and a fluophor modified at 5′-terminal. It was found that the guanine bases at the 3′-terminal could quench the fluorescence of the fluophor such as tetramethyl-6-carboxyrhodamine (TAMRA) at the 5′-terminal about 76.6% via electron transfer if the guanine bases are close enough to the fluophor, and the quenched fluorescence could get restored when the target protein is present since the interaction, which could be confirmed by measuring fluorescence lifetime, between TAMRA-aptamer and the target protein forces the guanines away from TAMRA so that TAMRA-modified aptamer changes into turn-on state. A linear relationship was then constructed between the turn-on fluorescence intensity and the concentration of PrPC in the range from 1.1 to 44.7 μg/mL with a limit of detection of 0.3 μg/mL (3σ).
Co-reporter:Yi Wang, Yuan Fang Li and Cheng Zhi Huang
The Journal of Physical Chemistry C 2009 Volume 113(Issue 11) pp:4315-4320
Publication Date(Web):2017-2-22
DOI:10.1021/jp809708q
With our newly prepared novel chitosan−ninhydrin (CHIT-NH) bioconjugate in this contribution, we made one-dimensional (1-D) assemblies of gold nanoparticles (NPs) at physiological temperature. This 1-D assembly method is simple, one-pot, and totally green wherein multiplex functional groups of the CHIT-NH conjugate make the nonuniform spatial distribution of stabilizers to form organized 1-D assemblies. UV−vis and infrared spectroscopy have been employed for identifying the molecular structure of CHIT-NH conjugate, while scanning electron microscopy (SEM), transmission electron microscopy (TEM) for confirming the 1-D morphology of gold NP assemblies. Mechanism investigations on the basis of the measurements of dynamic light scattering (DLS), time-dependent optical spectra, visible observation on the change of solution color and SEM imaging showed that the CHIT-NH conjugate, a novel environmentally benign and excellently biocompatible material, serves not only as a reducing agent but also as a stabilizer for the growth and 1-D assembly of gold NPs.
Co-reporter:Feng Ling Guo;Yuan Fang Li
Luminescence 2009 Volume 24( Issue 3) pp:150-154
Publication Date(Web):
DOI:10.1002/bio.1081
Abstract
The interactions of cobalt(II)–4-[(5-chloro-2-pyridyl)azo]-1,3-diaminobenzene (5-Cl-PADAB) complex with different kinds of homopolymer oligonucleotides in basic medium were investigated based on the measurements of resonance light scattering, UV–vis, circular dichroism spectra and dark field light-scattering imaging. Experiments showed that only thymidine homopolymer (poly T) oligonucleotides with the length in the range of poly T6 to poly T18 could interact with the Co(II)–5-Cl-PADAB complex in alkaline conditions and cause evident color and spectral change. Thus, the binary complex of Co(II)–5-Cl-PADAB could be employed as a visual probe for selectively recognizing the poly T oligonucleotides. Copyright © 2009 John Wiley & Sons, Ltd.
Co-reporter:Yue Liu;Jian Ling;YuanFang Li;ChengZhi Huang
Science China Chemistry 2009 Volume 52( Issue 5) pp:639-643
Publication Date(Web):2009 May
DOI:10.1007/s11426-009-0046-7
Silver nanoparticles (AgNPs), owing to the property of plasmon resonance light scattering (PRLS), can be used as a light scattering spectral probe for visually tracing and detecting target molecules. In this study, we investigated the adsorption features of proteins immobilized on glass slides for AgNPs, and found that the scattering light of AgNPs adsorbed on the surface of glass slides could be seen by naked eyes under the irradiation of a common white light-emitting diode (LED) torch. Hereby, we established a method for visually determining the least complete quantity of immobilization of proteins on glass slides.
Co-reporter:Jian Wang;Hao Wu;ChengZhi Huang
Science China Chemistry 2009 Volume 52( Issue 2) pp:188-195
Publication Date(Web):2009 February
DOI:10.1007/s11426-008-0127-z
The morphological transformation process of gold nanorods (Au-NRs) resulting from the reaction between tetracycline and iodine was monitored by the plasmon resonance absorption (PRA) spectra and the scanning electron microscope (SEM) images. It was found that iodine could fuse Au-NRs into sphericity with the lower aspect ratio and blue shift of the longitudinal PRA band. It was found, however, that the presence of tetracycline, since it can react with I2, decreases the effective concentration of I2 and its fusion effect on Au-NRs. As a result, the longitudinal PRA of Au-NRs shifts to longer wavelength linearly with increasing the concentration of tetracycline. With that, tetracycline can be detected in the range of 5.0×10∮5- 5.0×10−4 mol·L−1, with a limit of determination (LOD) of 2.4×10−6 mol·L−1 (3σ). Most foreign substances in the samples did not interfere in the detection, and tetracycline in the synthetic samples could be detected with the recovery in the range of 92.8%–107.2%, and RSD lower than 4.3%. The concentration of tetracycline in milk detected with standard addition method was so low that it accorded with the safety regulation.
Co-reporter:Wei He, Cheng Zhi Huang, Yuan Fang Li, Jian Ping Xie, Rong Ge Yang, Pei Fu Zhou and Jian Wang
Analytical Chemistry 2008 Volume 80(Issue 22) pp:8424
Publication Date(Web):October 20, 2008
DOI:10.1021/ac801005d
A one-step label-free optical genosensing method has been developed in this contribution by taking short DNA target with its sequence related to the human immunodeficiency virus type 1 (HIV-1) as an example. By employing anisotropic nonspherical and positively charged gold nanorods (Au-NRs) as the recognition platform, which show high stability against aggregation under high ionic strength conditions without any additional stable reagent, we found that the addition of target DNA to the mixture of nonmodified Au-NRs suspension and label-free probe DNA in high ionic strength buffer leads to a color change from red to light purple in less than 5 min, displaying strong plasmon resonance light scattering (PRLS) signals. Mechanism investigations showed that the strong PRLS signals should be ascribed to the aggregation of Au-NRs induced by the formed double-stranded oligonucleotides (dsDNA) from the hybridization of target DNA with probe DNA. With the PRLS signals, we monitored the hybridization process of a 21-mer single-stranded oligonucleotide (ssDNA) from the HIV-1 U5 long terminal repeat (LTR) sequence with its complementary oligonucleotide and detected the effect of single-base-pair mismatches. Two polymerase chain reaction (PCR) amplicon artificial samples derived from Mycobacterium tuberculosis glmS and genes encoding for Bacillus glucanase and an HIV-1 LTR sample isolated from HIV-1-positive blood were detected with satisfactory results, showing that the present method has simplicity, sensitivity, specificity, and reliability for sequence-specific DNA detection related to the HIV gene.
Co-reporter:Jian Wang, Yuan Fang Li, Cheng Zhi Huang, Tong Wu
Analytica Chimica Acta 2008 Volume 626(Issue 1) pp:37-43
Publication Date(Web):19 September 2008
DOI:10.1016/j.aca.2008.07.037
A detection method of cysteine is reported in this contribution with water-soluble positively charged gold nanoparticles (Au-NPs) that were prepared by seed-mediated method and capped with cetyltrimethylammonium bromide (CTAB). In aqueous medium of pH 4.2, the CTAB-capped Au-NPs display greatly different features from those of generally prepared citrate-coated Au-NPs. It was found that in a medium of high salt concentration, the presence of cysteine could induce aggregation of CTAB-capped Au-NPs, while citrate-coated Au-NPs could get aggregation soon even if without the presence of cysteine. The cysteine-induced aggregates of CTAB-capped Au-NPs display strong plasmon resonance light scattering (PRLS) signals characterized at 566.0 nm when excited by a light beam, and the PRLS intensities of the aggregates are in proportion to the concentration of cysteine in the range of 0.01–0.40 μg mL−1 with the limit of detection (3σ) being 2.9 ng mL−1. No amino acids in the samples interfere with the detection, and cysteine in artificial samples could be detected with the recovery between 95.3% and 105.9%, and R.S.D. is less than 3.6%.
Co-reporter:Yun Fei Long, Cheng Zhi Huang, Rong Xing He, Yuan Fang Li
Analytica Chimica Acta 2008 Volume 624(Issue 1) pp:128-132
Publication Date(Web):22 August 2008
DOI:10.1016/j.aca.2008.06.031
Light scattering (LS) signals have been applied for analytical detections, but the selectivity is poor. In order to improve the selectivity, pre-separation or new machines are generally considered. Differing from these methods, we synthesized a highly selective oxamide ligand, N′,N′-bis (2-aminophenyl) oxamide (NAPO). It was found that the LS signals of NAPO, measured with a common spectrofluorometer, could be selectively enhanced by copper ion in neutral medium. Thus, a new highly selective detection method for copper ion could be developed over the range of 0.9–31.0 μM with the limit of determination of 97.6 nM (3σ). Foreign ions including Cd(II), Al(III) could be allowed even if present at the level of 7-fold more than that of Cu2+, avoiding pre-separation procedures from complicated samples such as real wastewater samples. Mechanism studies showed that the reaction between NAPO and copper ion could form some kinds of clusters and induce the enhanced LS signals.
Co-reporter:Qing Zhang, Cheng Zhi Huang, Jian Ling and Yuan Fang Li
The Journal of Physical Chemistry B 2008 Volume 112(Issue 51) pp:16990-16994
Publication Date(Web):December 4, 2008
DOI:10.1021/jp8081535
The ability to construct size- and shape-controllable architectures is essential for the exploration of nanoparticle-structured properties, and it is a good strategy of employing metal nanoparticles embedded in a polymer matrix in order to prepare new materials with particular properties. Herein, we found that adenosine-5′-triphosphate (ATP) could be applied to adjust and control the formation of silver nanocubes (Ag-NCs) on Nafion film. Nafion could be saturated with [Ag(NH3)2]+ when incubated in silver ammonia solution, and it was found that the Nafion film saturated with [Ag(NH3)2]+ becomes yellow after immerged in a mixture containing NaOH, ATP, and formaldehyde, resulting in monodisperse Ag-NCs on the film. Thus, ATP as a molecular mediator and Nafion film as a polymer matrix are employed toward the preparation of size-controllable and monodisperse Ag-NCs, and a novel visual method for formaldehyde is further developed on the basis of the color change of the Nafion film, which gives sensitive detection of formaldehyde with a limit of determination of 60 ppb (3σ).
Co-reporter:Li Zhang, Cheng Zhi Huang, Yuan Fang Li, Sai Jin Xiao and Jian Ping Xie
The Journal of Physical Chemistry B 2008 Volume 112(Issue 23) pp:7120-7122
Publication Date(Web):May 20, 2008
DOI:10.1021/jp800092r
A detection method for DNA sequence-specificity in a homogeneous medium is presented with multiwalled carbon nanotubes (MWCNTs) as optical probes on the basis of the measurements of light scattering signals. ssDNA can prevent MWCNTs from coagulation in electrolyte solution while dsDNA cannot, displaying different light scattering signals. With the light scattering signals, target DNA in the range of 8.6–86.4 nM could be detected and one base pair mismatch could be discriminated. The sequence specificity for the present method has been identified with PCR products.
Co-reporter:Jian Wang ; Yuan Fang Li
The Journal of Physical Chemistry C 2008 Volume 112(Issue 31) pp:11691-11695
Publication Date(Web):July 16, 2008
DOI:10.1021/jp801993n
The morphological transformation process resulting from the reaction between Au nanorods (NRs) and iodine in situ produced from the redox between potassium iodide and copper chloride was monitored by virtue of the transmission electron microscope (TEM) images and the plasmon resonance absorption (PRA) spectra. It was found that the presence of copper chloride or potassium iodide could make the longitudinal PRA band of Au-NRs shift without any change of morphological transformation owing to the change of the refractive index of the medium. Different from that, iodine, which was in situ produced from the redox of potassium iodide and copper chloride, could fuse Au-NRs in the side-by-side mode, resulting in morphological transformation of Au-NRs to sphericity with the characteristics of the decrease of aspect ratio, blue-shift of the longitudinal PAR band, red-shift of transverse PRA band, and broadening of both longitudinal and transverse PRA bands of Au-NRs. The blue-shifted wavelength of the longitudinal PRA band was found to be in proportion to the concentration of copper chloride or potassium iodide when potassium iodide or copper chloride is sufficient, supplying the possibility to detect copper and iodine element in samples with spectrophotometry.
Co-reporter:Cheng Zhi Huang and Shao Fen Chen
The Journal of Physical Chemistry B 2008 Volume 112(Issue 37) pp:11785-11793
Publication Date(Web):August 26, 2008
DOI:10.1021/jp802895b
By simultaneously scanning both the excitation and emission monochromators of a common spectrofluorometer with same starting excitation and emission wavelength (namely, Δλ = 0), we obtained synchronous light scattering (SLS) signals that related to Rayleigh and Mie scatterings. It was found that the SLS signals could be applied for quantitation and differentiation of model bioparticles such as Saccharomyces cerevisiae, Schizosaccharomyces pombe, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Bacillus thuringiensis and Bacillus megaterium. In PBS buffer, these model bioparticles could form colloidal suspensions or dispersions of sizes ranging from hundreds of nanometers to tens of micrometers, giving SLS signals with the intensity being proportional to the amount of bioparticles in the range from 1.7 × 105 to 1.7 × 109 CFU/mL. A further finding is that polarized synchronous light scattering (PSLS) signals of I0°−30° against I0°−0°, which could be obtained by introducing polarizing sheets accessory of the spectrofluorometer, and the derivative synchronous light scattering (DrSLS) signals, which could be obtained directly with the extension function of the spectrofluorometer, offer differentiation information of bioparticles connected with their size, shape, refractive indexes, and inner structure. Refractive indexes of spherical bacteria were then calculated based on light scattering signals.
Co-reporter:Shu Jun Zhen, Yuan Fang Li, Cheng Zhi Huang, Yun Fei Long
Talanta 2008 Volume 76(Issue 1) pp:230-232
Publication Date(Web):30 June 2008
DOI:10.1016/j.talanta.2008.02.030
By designing and coupling a functional peptide, Gly-Leu-Ala-Cys-Ser-Gly-Phe-Pro-Arg-Gly-Arg-Trp, which could be cleaved by thrombin at the site of Arg-Gly (R-G), to the surface of gold nanoparticles (Au-NPs), we propose a simple spectrofluorometry for thrombin (TRB) in this contribution. Experiments showed that the peptide coupled to the surface of Au-NPs in a Tris–HCl buffer at 37 °C could be cleaved, leaving the fluorescent fragment of Gly-Arg-Trp in the Au-NPs suspension. By centrifuging the suspension and measuring the fluorescence signals resulting from the Trp residue of Gly-Arg-Trp fragment in the supernatant, we found that the fluorescence intensity is proportional to thrombin concentrations in the range of 1–100 nM with the limit of the detection of 0.1 nM. Since there are a lot of enzymes that can hydrolyze peptide with special sequence, and novel nanomaterials that can bind with the tryptophan-contained peptide and understand centrifugation, this spectrofluorometric method is general and it is possible to develop a variety of detection method for target enzymes.
Co-reporter:Qin Zhang, Yuan Fang Li, Cheng Zhi Huang
Talanta 2008 Volume 76(Issue 1) pp:44-48
Publication Date(Web):30 June 2008
DOI:10.1016/j.talanta.2008.01.066
Quality control (QC) is of great importance since the pharmaceutical quality not only directly affects the curative effect of the drugs, but also relates to human health and safety closely. Capillary electrophoresis (CE) has recently become a good alternative for pharmaceutical analysis and a complementary technique to high-performance liquid chromatography since it possesses many unique advantages. In this contribution, we propose a simple and reliable capillary zone electrophoretic method for the detection of piperaquine (PQ) in pharmaceutical formulations in terms of quality control, which might be of use to those working on similar compounds. The influence of buffer type, buffer pH, buffer concentration, buffer additive, applied voltage, capillary temperature and injection amount was systemically investigated and the proposed method was then successfully applied to the quality control of piperaquine in its pharmaceutical formulations. With quinine (QN) as an internal standard to improve precision, this method was suitably validated with respect to the linearity, limit of detection and quantification, accuracy, precision, specificity and stability.
Co-reporter:Cheng Zhi Huang, Qie Gen Liao, Yuan Fang Li
Talanta 2008 Volume 75(Issue 1) pp:163-166
Publication Date(Web):15 March 2008
DOI:10.1016/j.talanta.2007.10.049
With water-soluble anionic tetra (p-carboxyphenyl) porphyrin (TCPP) to solubilize multi-walled carbon nanotubes (MCNTs), we obtained a suspension that could be stable more than 1 week. With this TCPP/MCNTs suspension, we propose a spectrofluorometric method of DNA hybridization in this contribution. Our basic finding for this work is that the fluorescence from a dye-tagged single stranded DNA (ssDNA), which was directly added to the TCPP/MCNTs suspension, gets quenched, and the fluorescence could be remained if the dye-tagged single stranded DNA is first to be hybridized with its complementary target DNA to form a double stranded DNA (dsDNA) hybrid and added into the TCPP/MCNTs suspension. Mechanism investigations showed that the reason for the former is due to the adsorption of ssDNA on the surfaces of MCNTs, and that for the latter is due to the strong electrostatic repulsion force between the negative charge TCPP/MCNTs complexes and dsDNA. Thus, target DNA in a DNA sample and single-base mismatch in DNA sequences could be easily detected.
Co-reporter:Po Hu;ChengZhi Huang;Li Zhang
Science China Chemistry 2008 Volume 51( Issue 9) pp:866-871
Publication Date(Web):2008 September
DOI:10.1007/s11426-008-0090-8
It was found that multi-walled carbon nanotubes (MWNTs) could catalyze the redox reaction between chlorauric acid (HAuCl4) and reductive drugs such as tetracycline hydrochloride (TC), producing gold nanoparticles (Au NPs). By measuring the plasmon resonance light scattering (PRLS) signals of the resulting Au NPs, tetracycline hydrochloride can be detected simply and rapidly with a linear range of 4–26 μmol/L, a correlated coefficient (r) of 0.9955, and a limit of detection (3σ) of 6.0 nmol/L. This method has been successfully applied to the detection of tetracycline hydrochloride tablets in clinic with the recovery of 101.9% and that of fresh urine samples with the recovery of 98.3%–102.0%.
Co-reporter:Hui Ying Wang, Cheng Zhi Huang
Analytica Chimica Acta 2007 Volume 587(Issue 1) pp:142-148
Publication Date(Web):21 March 2007
DOI:10.1016/j.aca.2007.01.003
It is known that Raman scattering signals are one of main interference sources leading up to determination errors in spectrofluorometry, and thus the signals can be easily detected with a common spectrofluorometer. In this contribution, we propose a quantitative method based on the inner filter effect (IFE) of reagents on the Raman scattering signals of solvent by taking the complexation of divalent cobalt ion with 4-[(5-chloro-2-pyridyl)azo]-1,3-diaminobenzene (5-Cl-PADAB) as a model system. By adjusting the excitation wavelength of the spectrofluorometer, we could easily detect the Raman scattering signals of water at 424 nm where the maximum absorption of 5-Cl-PADAB reagent is located. In a solution of 5-Cl-PADAB, the Raman scattering signals of water are decreased owing to the IFE of 5-Cl-PADAB. If Co(II), which could form the binary complex of Co(II)/5-Cl-PADAB and consumes the 5-Cl-PADAB reagent, is present in such a case for a given amount of 5-Cl-PADAB solution, recovered Raman scattering signals could be observed and measured with a spectrofluorometer. It was found that the intensity of the enhanced Raman scattering signals is proportional to the Co(II) concentration over the range from 2.0 × 10−7 mol L−1 to 1.0 × 10−5 mol L−1, and the detection limit could reach 1.2 × 10−7 mol L−1. With that, Co(II) in samples could be detected with R.S.D. values lower than 2.6% and recoveries over the range of 97.2–104.7%.
Co-reporter:Zhong De Liu, Shao Fen Chen, Cheng Zhi Huang, Shu Jun Zhen, Qie Gen Liao
Analytica Chimica Acta 2007 Volume 599(Issue 2) pp:279-286
Publication Date(Web):19 September 2007
DOI:10.1016/j.aca.2007.07.075
In this contribution, we report a rapid optical detection method of pathogens using Staphylococcus aureus (S. aureus) as the model analyte based on the molecular recognition of immunoglobulin with cell wall-associated Protein A (SpA). It was found that the molecular recognition of human immunoglobulin (IgG) with protein A on the cell wall of S. aureus on glass slide sensing area could result in strong surface enhanced light scattering (SELS) signals, and the SELS intensity (ΔI) increases proportionally with the concentration of S. aureus over the range of 2.5 × 105–1.0 × 108 CFU mL−1 with right angle light scattering (RALS) signals detection mode. In order to identify the solid support based molecular recognition between IgG with SpA, we also employed water-soluble CdS quantum dots (CdS-QDs) as a fluorescent marker for IgG by immobilizing the IgG onto the surfaces of CdS-QDs through covalent binding in order to generate recognition probes for SpA on the cell wall of S. aureus. Consequently, the fluorescent method also showed that the detection for pathogens with solid supports is reliable based on the molecular recognition of IgG with SpA.
Co-reporter:Cheng Zhi Huang, Qie Gen Liao, Li Hua Gan, Feng Ling Guo, Yuan Fang Li
Analytica Chimica Acta 2007 Volume 604(Issue 2) pp:165-169
Publication Date(Web):5 December 2007
DOI:10.1016/j.aca.2007.10.016
It has been reported that adsorption of uncoiled DNA (u-DNA) on the surface of gold nanoparticles (Au-NPs) can prevent the nanoparticle suspensions from aggregation even if in salt medium. Herein we report that quadruplex DNA (q-DNA), which is formed from uncoiled telomere DNA, via intramolecular hydrogen bonds in the presence of potassium ion, cannot keep Au-NPs stable, and the q-DNA/Au-NPs coexisting suspensions display aggregation tendency, giving plasmon resonance light scattering (PRLS) signals of Au-NPs. Mechanism investigations through a single point energy calculation on u- and q-structures of telomere DNA showed that q-DNA, compared with u-DNA, has a much higher surface negative charge density, symmetrical charge distribution and well self-structural stabilization, could not be adsorbed on the surface of Au-NPs.
Co-reporter:XiaoHui Zhao;ChengZhi Huang
Science Bulletin 2007 Volume 52( Issue 4) pp:456-460
Publication Date(Web):2007 February
DOI:10.1007/s11434-007-0092-5
In acid buffer solution, proteins with positive charge can react with anion surfactant and result in a great enhancement of synchronous light scattering (SLS) signals. In this contribution, the correlative experiment was made to compare the interaction of human serum albumin (HSA) and immunoglobulin G (IgG) with sodium dodecyl sulfonate (SDS). Based on the measurements of the polarization light scattering signals, a new method of scattering polarization was constituted to distinguish these two interaction systems with molecular weight difference (HSA 66 kDa; IgG 150 kDa). The results were consistent with the data measured by dynamic light scattering (DLS) technique.
Co-reporter:Qie Gen Liao, Yuan Fang Li, Cheng Zhi Huang
Talanta 2007 Volume 71(Issue 2) pp:567-572
Publication Date(Web):15 February 2007
DOI:10.1016/j.talanta.2006.04.035
Any signals, if their intensities have simple functional relationship with analyte concentration, can be applied to analytical purposes. Rayleigh light scattering signals and fluorescence signals are twins in flurospectroscopy, so the light scattering signals are the major interference when the Stokes shift is small. Herein, we propose a light scattering and fluorescence emission (LS–FL) coupled ratiometry using CdS quantum dots (QDs) as a fluorescence probe to detect aminoglycoside antibiotics (AGs). As model analytes, AGs, when attached to the surface of CdS-QDs via electrostatic interaction in aqueous medium, result in strong enhanced light scattering (LS) emission characterized at 376 nm and fluorescence quenching of CdS-QDs at 500 nm. Thus, a ratiometry using the coexistent light scattering and fluorescent emission signals has been proposed. Based on the linear relationship between logarithm of light scattering and fluorescence emission ratio (R) and logarithm of AGs concentration, a novel assay of AGs is established with the limits of detection (3σ) being 58–190 nmol l−1, and applied successfully to detect AGs injection and serum samples.
Co-reporter:Yun Fei Long, Cheng Zhi Huang
Talanta 2007 Volume 71(Issue 5) pp:1939-1943
Publication Date(Web):30 March 2007
DOI:10.1016/j.talanta.2006.08.036
The interaction of Amido black 10B (AB) with DNA in basic medium was studied in the presence of cetyltrimethylammonium bromide (CTMAB) based on the measurements of resonance light scattering (RLS), UV–vis, CD spectra, and RLS imaging. The interaction has been proved to give a ternary complex of CTMAB–DNA–AB in Britton–Robinson buffer of pH 11.55, which exhibits strong negative Cotton effect at 233.3 nm and 642.8 nm, and strong RLS signals characterized at 469 nm. Experiments showed that the enhanced RLS intensities (ΔIRLS) against the mixture of AB and CTMAB are proportional to the concentration of fish sperm DNA (fsDNA) and calf thymus DNA (ctDNA), respectively over the range of 0.03–1.0 and 0.05–1.5 μg ml−1, with the limits of determination (3σ) of 7.3 ng ml−1 for fsDNA and 7.0 ng ml−1 for ctDNA.
Co-reporter:Hui Ying Wang, Yuan Fang Li, Cheng Zhi Huang
Talanta 2007 Volume 72(Issue 5) pp:1698-1703
Publication Date(Web):31 July 2007
DOI:10.1016/j.talanta.2007.02.028
Co-reporter:Zhong De Liu, Cheng Zhi Huang, Yuan Fang Li, Yun Fei Long
Analytica Chimica Acta 2006 Volume 577(Issue 2) pp:244-249
Publication Date(Web):8 September 2006
DOI:10.1016/j.aca.2006.06.059
Gold nanoparticles are known for their plasmon resonance absorption (PRA) depending on their size. Our this investigation shows that plasma resonance light scattering (PRLS) signals in the corresponding PRA region could be measured using a common spectrofluorometer, and be enhanced when aggregation of gold nanoparticles occurs due to their interaction with organic small molecules (OSMs). Using captopril (Cap) as an example, we investigated the interactions of gold nanoparticles with OSMs in order to propose a general method of OSMs such as typical clinic organic drugs. In aqueous medium of pH 2.09, there are about 2.2 × 103 Cap molecules covalently binding to the surface of a 10-nm diameter gold nanoparticle through the thiol functional group of Cap, and thus forms a core-shell assembly of [(Au)31000]@[(Cap)2200], displaying strong enhanced PRLS signals in the PRA region of gold colloid. The PRLS intensities characterized at 553.0 nm were found to be proportional to the concentration of Cap over the range of 0.1–1.7 mg L−1 with the determination limit (3σ) of 32.0 μg L−1. With that, Cap in pharmaceutical preparations could be determined with the recovery of 97.0–104.5% and R.S.D. of less than 2.4%.
Co-reporter:Hua Wen Zhao, Cheng Zhi Huang, Yuan Fang Li
Analytica Chimica Acta 2006 Volume 564(Issue 2) pp:166-172
Publication Date(Web):6 April 2006
DOI:10.1016/j.aca.2006.01.096
An optical immunosensor based on measuring the surface enhanced light scattering (SELS) signals is developed by simultaneously scanning the excitation and the emission monochromators of a common spectrofluorometer. The formation of silanization on solid surface of glass slides and the binding of antibody with antigen in series have been confirmed by measuring the SELS signals. When 100 μg ml−1 goat anti-human IgG, goat anti-rabbit IgG and rabbit anti-human IgG are immobilized on the solid surface, human IgG and rabbit IgG in the range of 0.1–100 μg ml−1 and human IgG in the range of 0.1–10 μg ml−1 could be detected, and the lowest detectable concentration could, respectively, reach 10, 50 and 10 ng ml−1. This label-free assay is more rapid and simpler than those conventional immunoassay methods. Under optimal experimental conditions, the sensor based on SELS has a high specificity with corresponding antigen (Ag), and other co-existing proteins in solution, for example, such as bovine serum albumin (BSA) and human serum albumin (HSA) do not show interference effect. Regenerated simply by rinsing in carbamide solution, the sensor could achieve three assay cycles without great loss of sensitivity.
Co-reporter:Jian Ling, Cheng Zhi Huang, Yuan Fang Li
Analytica Chimica Acta 2006 Volume 567(Issue 2) pp:143-151
Publication Date(Web):17 May 2006
DOI:10.1016/j.aca.2006.03.059
Investigations of inorganic oligomers are important in both chemistry and physiology. In this contribution, we propose a laser induced light scattering imaging (LSI) and a total internal reflected light scattering imaging (TIR-LSI) technique, and apply them to characterize the interactions of inorganic oligomers with biopolymer in aqueous phase and at liquid/liquid interface, respectively. In aqueous medium, synthetic chromium(III) hydrolytic oligomers (CrHO) react with DNA, and the resultant binary could be extracted into the H2O/CCl4 interface in the presence of triocyctyl phosphine oxide (TOPO), forming a DNA–CrHO–TOPO ternary amphipathic complex at the interface with the associate constant of 1.32 × 103 mol−1 dm4 for a given 1.0 × 10−4 mol l−1 TOPO. Under the excitation of a 441-nm He–Cd laser light beam, the resultant light scattering and total internal reflected light scattering (TIR-LS) signals of the formed binary in aqueous phase and ternary at liquid/liquid interface could be easily captured using a common microscope coupled with a CCD camera. By digitally analyzing the CCD captures, we demonstrate that aggregations of the CrHO–DNA binary in aqueous phase and DNA–CrHO–TOPO ternary at liquid/liquid interface have occurred, respectively.
Co-reporter:Hua Wen Zhao, Cheng Zhi Huang, Yuan Fang Li
Talanta 2006 Volume 70(Issue 3) pp:609-614
Publication Date(Web):15 October 2006
DOI:10.1016/j.talanta.2006.01.019
A sensitive, highly specific immunoassay method has been developed by measuring the enhanced resonance light scattering (RLS) signals of immunoreactions with simultaneously scanning both the excitation and the emission monochromators of a common spectrofluorometer. For a given content of antibody (Ab), the RLS signals of an immunoreaction follow Gaussian distribution with antigen (Ag) concentration. The central position of the Gaussian curve represents the concentration of given Ab, and the half bandwidth has proved to be a characteristic constant of a given Ab–Ag immunoreaction. With the RLS signals, the limit of detection for human immunoglobulin G (HIgG) in serum samples could reach 10 ng ml−1, and the concentration of HIgG in blood serum samples could be detected with the recovery of 90.2–107.7% and R.S.D. of 0.8–2.7%. The results of determination for three human serum samples are identical to those obtained by immunoturbidimetry.
Co-reporter:Cheng Zhi Huang, Xiao Bing Pang, Yuan Fang Li, Yi Juan Long
Talanta 2006 Volume 69(Issue 1) pp:180-186
Publication Date(Web):15 March 2006
DOI:10.1016/j.talanta.2005.09.022
Resonance light scattering (RLS) technique is a creative application of light scattering signals detected by using a common spectrofluorometer, but it has drawbacks such as the fluctuation of signals caused by poorly quantified or variable factors. Herein we develop a RLS ratiometry to overcome the drawbacks of the technique and apply to measure the binding nature of organic small molecules (OSM) with biopolymer using the binding of cation porphyrins with heparin (HP) as an example. In near neutral solution, cationic porphyrins meso-tetrakis [(trimethylammoniumyl) phenyl] porphyrin (TAPP) and meso-tetra (4-methylpyridy) porphyrin (TMPyP-4) interact with heparin, resulting in hypochromatic effect, and enhanced RLS signals. Linear relationship could be established between the ratio of enhanced RLS signals at two wavelengths, where the maximum and minimum are available in the ratio curve of UV–vis spectrum of porphyrin to that of heparin–porphyrin complex, and the logarithm of heparin concentration, and thus a wide dynamic range detection method of biopolymers could be developed. In comparison with RLS method, this RLS ratiometric one is less affected by environmental conditions such as pH, ionic strength. The mechanism of these interactions was investigated based on the charge density distribution of the two porphyrin molecules and it could be concluded that the enhanced RLS intensity is proportionally promoted by the charge capacity of components in the complex. Additionally, the binding number and binding constant were measured scientifically by Scatchard plot.
Co-reporter:Chun Mei Li, Lin Ling Zheng, Xiao Xi Yang, Xiao Yan Wan, Wen Bi Wu, Shu Jun Zhen, Yuan Fang Li, Ling Fei Luo, Cheng Zhi Huang
Biomaterials (January 2016) Volume 77() pp:216-226
Publication Date(Web):January 2016
DOI:10.1016/j.biomaterials.2015.11.008
Viral infections have caused numerous diseases and deaths worldwide. Due to the emergence of new viruses and frequent virus variation, conventional antiviral strategies that directly target viral or cellular proteins are limited because of the specificity, drug resistance and rapid clearance from the human body. Therefore, developing safe and potent antiviral agents with activity against viral infection at multiple points in the viral life cycle remains a major challenge. In this report, we propose a new modality to inhibit viral infection by fabricating DNA conjugated gold nanoparticle (DNA-AuNP) networks on cell membranes as a protective barrier. The DNA-AuNPs networks were found, via a plaque formation assay and viral titers, to have potent antiviral ability and protect host cells from human respiratory syncytial virus (RSV). Confocal immunofluorescence image analysis showed 80 ± 3.8% of viral attachment, 91.1 ± 0.9% of viral entry and 87.9 ± 2.8% of viral budding were inhibited by the DNA-AuNP networks, which were further confirmed by real-time fluorescence imaging of the RSV infection process. The antiviral activity of the networks may be attributed to steric effects, the disruption of membrane glycoproteins and limited fusion of cell membrane bilayers, all of which play important roles in viral infection. Therefore, our results suggest that the DNA-AuNP networks have not only prophylactic effects to inhibit virus attachment and entry, but also therapeutic effects to inhibit viral budding and cell-to-cell spread. More importantly, this proof-of-principle study provides a pathway for the development of a universal, broad-spectrum antiviral therapy.
Co-reporter:Chun Mei Li, Lin Ling Zheng, Xiao Xi Yang, Xiao Yan Wan, Wen Bi Wu, Shu Jun Zhen, Yuan Fang Li, Ling Fei Luo, Cheng Zhi Huang
Biomaterials (January 2016) Volume 77() pp:216-226
Publication Date(Web):January 2016
DOI:10.1016/j.biomaterials.2015.11.008
Co-reporter:Shujun Zhen, Xiaoyan Wan, Linling Zheng, Chunmei Li, Chengzhi Huang
Science Bulletin (April 2016) Volume 61(Issue 8) pp:639-644
Publication Date(Web):1 April 2016
DOI:10.1007/s11434-016-1049-3
A novel sensitive semi-quantitative virus detection technique was developed using the respiratory syncytial virus (RSV) as an example, through dark-field light scattering imaging of the surface state of the virus-invaded host cells. In this method, anti-RSV-antibody modified gold nanoparticles (AuNPs) could bind with the invading virus on the cell membrane of the infected host cells through the specific antibody-antigen binding. Then, the host cells could be imaged by the localized surface plasmon resonance light scattering properties of AuNPs under a dark-field light scattering microscopy, which could be further used to semi-quantify the invading virus.
Co-reporter:Chun Hong Li, Xue Xiao, Jing Tao, Dong Mei Wang, Cheng Zhi Huang, Shu Jun Zhen
Biosensors and Bioelectronics (15 May 2017) Volume 91() pp:
Publication Date(Web):15 May 2017
DOI:10.1016/j.bios.2016.12.010
•A novel fluorescent aptasensor for ricin detection was developed.•A low background reduced by graphene oxide was achieved.•An enhanced detection signal based on isothermal strand-displacement polymerase reaction was obtained.•Both the ricin B-chain and entire ricin toxin in real sample was successfully detected.•The aptasensor could be widely extended to the detection of other toxins.The toxic plant protein ricin is a potential agent for criminal or bioterrorist attacks due to the wide availability and relative ease of preparation. Herein, we developed a novel strategy for the detection of ricin B-chain (RTB) based on isothermal strand-displacement polymerase reaction (ISDPR) by using aptamer as a recognition element and graphene oxide (GO) as a low background platform. In this method, ricin-binding aptamer (RBA) hybridized with a short blocker firstly, and then was immobilized on the surface of streptavidin-coated magnetic beads (MBs). The addition of RTB could release the blocker, which could hybridize with the dye-modified hairpin probe and trigger the ISDPR, resulting in high fluorescence intensity. In the absence of RTB, however, the fluorescence of the dye could be quenched strongly by GO, resulting in the extremely low background signal. Thus, RTB could be sensitively detected by the significantly increased fluorescence signal. The linear range of the current analytical system was from 0.75 μg/mL to 100 μg/mL and the limit of detection (3σ) was 0.6 μg/mL. This method has been successfully utilized for the detection of both the RTB and the entire ricin toxin in real samples, and it could be generalized to any kind of target detection based on an appropriate aptamer.
Co-reporter:Lei Zhan, Wen Bi Wu, Lin Yang, Cheng Zhi Huang
Analytica Chimica Acta (15 April 2017) Volume 962() pp:
Publication Date(Web):15 April 2017
DOI:10.1016/j.aca.2017.01.023
•Signal amplification was achieved by integrating the high loading capacity of MBs with the stimulation effect of Zn2+.•The reverse plasmonic ELISA utilizing enzyme to disperse the aggregates could reduce the risk of false positive signals.•The amplified plasmonic immunoassay can be easily adapted for the detection of other pathogens.The timely detection of infectious pathogen is critical in clinical early diagnosis and treatment of infectious diseases. Plasmonic enzyme-linked immunosorbent assay (ELISA), by means of enzyme-mediated growth or aggregation of AuNPs, has received considerable attention because it allows a naked-eye detection of target in very low numbers. In this work, a dual-signal amplified plasmonic ELISA combined the high loading capacity of magnetic beads with the establishing stimulation effect of zinc ion has been developed to detect RSV as a model pathogen based on alkaline phosphatase-triggered dispersion of aggregated AuNPs. In ideal conditions, the proposed immunoassay can conveniently distinguish the concentration of RSV in a range of 0.1–30 pg/mL. In addition, the limit of detection of RSV of this immunoassay exceeds that of conventional ELISA by about 50 times. The high sensitivity makes this approach a good alternative to existing colorimetric immunoassays for pathogen detection.
Co-reporter:Bin Bin Chen, Rong Sheng Li, Meng Li Liu, Hong Zhi Zhang and Cheng Zhi Huang
Chemical Communications 2017 - vol. 53(Issue 36) pp:NaN4961-4961
Publication Date(Web):2017/03/31
DOI:10.1039/C7CC00546F
The easy fabrication of single-layered graphene quantum dots (s-GQDs) still faces challenge. Herein, we report an efficient route to fabricate s-GQDs within 5 min at room temperature by introducing a simple self-exothermic reaction. The as-prepared s-GQDs can specifically bind with aluminium ions to produce an aggregation-induced emission enhancement effect.
Co-reporter:Hong Yan Zou, Ming Xuan Gao, Tong Yang, Qiao Ling Zeng, Xiao Xi Yang, Feng Liu, Mark T. Swihart, Na Li and Cheng Zhi Huang
Physical Chemistry Chemical Physics 2017 - vol. 19(Issue 10) pp:NaN6968-6968
Publication Date(Web):2017/02/22
DOI:10.1039/C7CP00724H
Nonstoichiometric copper chalcogenides with heavy copper vacancies can be used as an effective photo-activated catalyst for the Huisgen [3+2] cycloaddition reaction as Cu(I) can be released corresponding to holes (Cu-defects) under light irradiation. These strategies expand new possibilities for carrying out prototypical click chemistry in the presence of functional groups.
Co-reporter:Heng Xin Zhao, Li Qin Liu, Zhong De Liu, Yi Wang, Xi Juan Zhao and Cheng Zhi Huang
Chemical Communications 2011 - vol. 47(Issue 9) pp:NaN2606-2606
Publication Date(Web):2011/01/13
DOI:10.1039/C0CC04399K
A simple method for phosphate (Pi) detection is established by developing an off–on fluorescence probe of europium-adjusted carbon dots (CDs), which has been successfully applied to the detection of Pi in very complicated matrixes such as artificial wetlands system.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 11) pp:
Publication Date(Web):
DOI:10.1039/C4AY00206G
A simple and label-free plasmon resonance light scattering (PRLS) assay for glucose was developed based on the formation of gold nanoparticles (AuNPs) from the redox between chlorauric acid (HAuCl4) and hydrogen peroxide (H2O2) in the presence of MES. It was found that the PRLS signals characterized at 550 nm were proportional to the content of H2O2, which could be produced in the process of biocatalytic reaction of glucose oxidase (GOx), and thus a RLS method of glucose was proposed with the linear range of 5.0 × 10−6 M to 1.0 × 10−4 M and the detection limit of 2.7 × 10−6 M.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 1) pp:
Publication Date(Web):
DOI:10.1039/C2AY26156A
The traditional molecular aptamer beacon (MAB) is designed by combining an aptamer to a molecular beacon, and its two terminals are labelled with a fluorescent moiety (donor) and quenching moiety (acceptor), respectively. However, it usually has a high background because of the low energy transfer efficiency between the donor and the acceptor. In order to overcome these drawbacks, we have developed a novel MAB with just one fluorescently labelled end, which acts as the donor, and graphene oxide (GO) introduced as the acceptor for target detection by employing long range resonance energy transfer (LrRET) as the signal-transduction mechanism from GO to MAB. To test the validity of the designed MAB system, cellular prion protein (PrPC) has been used as the model target. It was found that the fluorescence of the designed MAB is completely quenched by GO, supplying a very low background. Conversely, the quenched fluorescence is recovered significantly with the addition of PrPC, so that PrPC can be detected over a wide range of 10.2–78.8 μg mL−1 with a detection limit as low as 0.309 μg mL−1 and with high selectivity. This GO-based MAB approach is a successful application of LrRET for the detection of PrPC, with advantages such as low costs, high quenching efficiency and good specificity, and it opens up new opportunities for the sensitive detection of biorecognition events.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 14) pp:
Publication Date(Web):
DOI:10.1039/C4AY00181H
We report a simple Raman scattering method for the sensitive and selective detection of cobalt(II) ions using the combination of leaf-like poly(p-phenylenediamine) (PpPD) microcrystals and Ag nanoparticles (AgNPs) as the signal provider. The AgNPs provide much greater Raman scattering enhancement to the PpPD microparticles. However, it was found that the PpPD microparticles can be selectively etched and degraded by cobalt(II) ions, resulting in a decrease in Raman signal intensity. Therefore, the combination of PpPD microparticles and AgNPs provides an excellent Raman scattering signal readout platform for sensitive and specific cobalt(II) detection, and the decrease in Raman signal intensity is found to be proportional to the logarithm of cobalt(II) concentration over the range of 0.3–50 μM with a detection limit (3σ) of 20 nM.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 20) pp:
Publication Date(Web):
DOI:10.1039/C3AY41146J
In this paper, a new approach for respiratory syncytial virus (RSV) gene sequence detection was described based on the fluorescence resonance energy transfer (FRET) from oligonucleotide-templated silver nanoclusters (DNA–AgNCs) to multi-walled carbon nanotubes (MWCNTs). The specific DNA scaffold combines two fragments: one is enriched with a cytosine sequence fragment (C12) that can result in DNA–AgNCs with a high quantum yield via a chemical reduction method, and the other is the probe fragment (5′-AAA AAT GGG GCA AAT A-3′) which can selectively bind to the gene for RSV. Thus, the as-prepared AgNCs can exhibit enhanced fluorescence when binding to the target DNA sequence and forming a double helix. Because of the introduction of MWCNTs, which can quench the fluorescence of the DNA–AgNCs with an extraordinarily high quenching efficiency (85.8%), a relatively high signal-to-background ratio was achieved. The fluorescence ratio of the DNA–AgNCs was enhanced in a linearly proportional manner to the concentration of the target in the range of 31.25 nM to 2.00 μM with a detection limit (3σ) of 24.00 nM.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 18) pp:
Publication Date(Web):
DOI:10.1039/C4AY01411A
A simple and highly selective chemiluminescence (CL) detection method for K+ was developed based on a K+-stabilized G-qaudruplex DNAzyme, which catalyzes a luminol-H2O2 reaction system. Herein, a G-quadruplex DNAzyme stemming from a common guanine-rich DNA sequence named PS2.M is introduced as a catalyst. Upon the addition of K+, PS2.M is induced to fold into G-quadruplex as a cofactor binding with hemin, effectively catalyzing the redox reaction of luminol-H2O2. The reaction generates a CL emission and allows the DNAzyme to show a good horseradish peroxidase (HRP) mimicking-enzyme activity. The intensity of CL shows a linear dependence on the concentration of K+ within the range of 2–120 μM with a limit of detection (3σ) of 1.66 μM, giving a vital clue to quantify K+ content in urine samples. This strategy firstly opens up CL as an effective and facile approach to detect K+ with high selectivity.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 24) pp:
Publication Date(Web):
DOI:10.1039/C3AY41335G
We developed a new dual-aptamer based strategy to detect cellular prion protein through the fluorescence resonance energy transfer between quantum dots and graphene oxide, in which the distance between the energy donor and the acceptor ranges from 14 to 27 nm.
Co-reporter:
Analytical Methods (2009-Present) 2012 - vol. 4(Issue 6) pp:
Publication Date(Web):
DOI:10.1039/C2AY25166C
Because of its rich π electrons, graphene oxide (GO) can bind with single-stranded DNA (ssDNA) through π-π stacking, but it cannot bind with double-stranded DNA (dsDNA). This different binding ability of GO with DNA has found many applications. By combining this ability with aptamer chemistry, we have developed a highly selective method for the detection of adenosine triphosphate (ATP). The hybrid of ATP aptamer with fluorescein (FAM)-labelled complementary DNA (FAM-DNA) demonstrates a weak affinity for GO and strong fluorescence of FAM-DNA. If ATP is present the strong fluorescence of FAM-DNA is quenched, because the binding of ATP with its aptamer greatly inhibits hybridization of the aptamer with FAM-DNA, and the unhybridized FAM-DNA is adsorbed on to the surface of GO. The quenched fluorescence intensity was found to be in proportion to the concentration of ATP in the range 3–320 μM with a detection limit of 0.45 μM. This method of ATP detection is highly selective and the existence of GTP, CTP and UTP have scarcely effect the determination.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 3) pp:
Publication Date(Web):
DOI:10.1039/C2AY25971K
Developing new detection methods for drugs is compulsory in terms of pharmacological investigation and quality control. In this contribution, we developed a new spectrofluorometric method for 6-mercaptopurine (6-MP), an anticancer drug, by using CdTe quantum dots (QDs). It was found that the fluorescence of surface-carboxyl CdTe QDs could be effectively quenched by Cu2+ due to aggregation, but restored in the presence of 6-MP, due to the reduction of copper ions into cuprous ions by the disulfide of 6-MP. The restored fluorescence intensity had a linear relationship with the concentration of 6-MP in the range of 0.20–3.20 μmol L−1. With that, a new rapid sensitive spectrofluorometric method for 6-MP was developed.
Co-reporter:Jian Ling and Cheng Zhi Huang
Analytical Methods (2009-Present) 2010 - vol. 2(Issue 10) pp:NaN1447-1447
Publication Date(Web):2010/09/17
DOI:10.1039/C0AY00452A
Gold nanoparticles (AuNPs) are the most interesting nanomaterials for analytical purposes owing to their unique optical and electrochemical properties resulting from the localized surface plasmon resonance (LSPR) of the electrons, displaying strong absorption and scattering of light from visible to near-infrared region by tuning the particles sizes and shapes. In fluorescence resonance energy transfer (FRET) process, AuNPs have been identified to act as excellent acceptors to replace traditional organic quenchers. Starting from quenching advantages of AuNPs in FRET system and energy transfer mechanism of donor to AuNPs, herein we try to summarize and discuss typical AuNPs based FRET methods in terms of DNA hybridizations, immunoreactions, specific molecular bindings or adsorptions, and provide their analytical applications in biochemical and pharmaceutical analysis.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 21) pp:NaN6204-6204
Publication Date(Web):2013/09/09
DOI:10.1039/C3AY41219A
Noble metal nanoclusters, which have molecule-like properties and offer the missing understanding link between metal atoms and nanoparticles, have become a hot research topic due to their amazing properties. Herein, we develop a label-free, low-cost and sensitive fluorescence turn-off strategy for the detection of bleomycin (BLM) with strong fluorescent silver nanoclusters, wherein BLM coordinated with Fe2+ could highly oxidize the core of fluorescent silver nanoclusters. Under the optimal conditions, this strategy could be applied to the detection of BLM in the range of 100 to 400 nM with a detection limit of 54 nM.
Co-reporter:Yi Wang, Lei Zhan and Cheng Zhi Huang
Analytical Methods (2009-Present) 2010 - vol. 2(Issue 12) pp:NaN1988-1988
Publication Date(Web):2010/10/13
DOI:10.1039/C0AY00470G
We present a room-temperature strategy for the preparation of dextran-capped gold nanoparticles (AuNPs) in this contribution by employing dextran, which acts as both a reducing agent and a stabilizer, and thus well dispersed, uniform and biocompatible AuNPs could be successfully prepared in one pot. The investigations, including toxicological effect on cells and the capability of resisting aggregation in high ion medium, have demonstrated that the as-prepared AuNPs are biocompatible and stable even if in a medium of high ionic strength. In order to identify the practicability of the dextran-capped AuNPs, colorimetric detection of dihydralazine sulfate (DHZS) in uric samples based on the localized surface plasmon resonance (LSPR) of the AuNPs is made with the recovery in the range of 98.3–102.5%.
Co-reporter:Ze Xi Liu, Zhu Lian Wu, Ming Xuan Gao, Hui Liu and Cheng Zhi Huang
Chemical Communications 2016 - vol. 52(Issue 10) pp:NaN2066-2066
Publication Date(Web):2015/12/08
DOI:10.1039/C5CC08635C
Photoluminescent carbon dots (CDs), hydrothermally prepared using tannic acid (TA), show visual aggregation induced emission enhancement (AIEE) properties at 455 nm when excited at 350 nm owing to the rotational hindering of the surface groups on CDs such as aromatic rings and phenolic hydroxyl ones, causing exponential decay between the ratio of the photoluminescence intensity in organic solvents to that in water and the permittivity of the solvent, and thus dazzling emissions of the CDs in the presence of solvents with small permittivity, tetrahydrofuran (THF), for instance, could be visually observed.
Co-reporter:Lei Zhan, Chun Mei Li, Wen Bi Wu and Cheng Zhi Huang
Chemical Communications 2014 - vol. 50(Issue 78) pp:NaN11528-11528
Publication Date(Web):2014/08/06
DOI:10.1039/C4CC05155F
A novel colorimetric immunoassay for highly sensitive detection of respiratory syncytial virus (RSV), one of the leading causes of severe lower respiratory tract infections in all age groups, has been proposed based on Hg2+-stimulated peroxidase-like activity of gold nanoparticles–graphene oxide (AuNPs–GO) hybrids. This metal ion-enhanced immunoassay shows high promise in the field of biomedical sciences.
Co-reporter:Yan Yu, Yue Liu, Shu Jun Zhen and Cheng Zhi Huang
Chemical Communications 2013 - vol. 49(Issue 19) pp:NaN1944-1944
Publication Date(Web):2013/01/21
DOI:10.1039/C3CC38129C
Graphene oxide (GO) introduced to enhance the fluorescence anisotropy (FA) of fluorogens was identified to be effective for highly sensitive and selective detection of metal ions through an anisotropy DNAzyme-based strategy.
Co-reporter:Ming Xuan Gao, Chun Fang Liu, Zhu Lian Wu, Qiao Ling Zeng, Xiao Xi Yang, Wen Bi Wu, Yuan Fang Li and Cheng Zhi Huang
Chemical Communications 2013 - vol. 49(Issue 73) pp:NaN8017-8017
Publication Date(Web):2013/07/11
DOI:10.1039/C3CC44624G
Highly PL carbon quantum dots (CQDs) were successfully prepared from C60 by introducing CTAB and H2O2 in aqueous NaOH under hydrothermal conditions. The CQDs displayed a nanoparticle aggregation-induced emission enhancement (NP-AIEE).
Co-reporter:Yue Liu and Cheng Zhi Huang
Chemical Communications 2013 - vol. 49(Issue 74) pp:NaN8264-8264
Publication Date(Web):2013/07/12
DOI:10.1039/C3CC43605E
Single gold nanoparticles (AuNPs), whose scattering light intensity was digitized and expressed as digital information through common software, were used as digital recorders for probing molecular binding of avidin to biotin.
Co-reporter:Lin Ling Zheng, Xiao Xi Yang, Yue Liu, Xiao Yan Wan, Wen Bi Wu, Ting Ting Wang, Qiang Wang, Shu Jun Zhen and Cheng Zhi Huang
Chemical Communications 2014 - vol. 50(Issue 99) pp:NaN15779-15779
Publication Date(Web):2014/10/28
DOI:10.1039/C4CC06264G
An in situ labelling strategy was proposed to produce quantum dot-labelled respiratory syncytial viruses (RSVs) by incorporating the biotinylated membrane protein of the host cells into mature virions, followed by conjugation with streptavidin modified quantum dots (SA-QDs), which has the advantages such as convenience, efficiency and minor influence on viral infectivity and thus could be successfully applied to track the early stage of virus entry.
Co-reporter:Yue Liu, Jian Ling and Cheng Zhi Huang
Chemical Communications 2011 - vol. 47(Issue 28) pp:NaN8123-8123
Publication Date(Web):2011/06/20
DOI:10.1039/C1CC11503K
Colors of scattering light of single gold nanoparticles (AuNPs) were coded with the tricolor (RGB) system by assigning digital values to R, G and B and then this was applied to binding studies of thiols to AuNPs through RGB analysis.
Co-reporter:Shu Jun Zhen, Feng Ling Guo, Li Qiang Chen, Yuan Fang Li, Qing Zhang and Cheng Zhi Huang
Chemical Communications 2011 - vol. 47(Issue 9) pp:NaN2564-2564
Publication Date(Web):2011/01/04
DOI:10.1039/C0CC03205K
A novel type of leaf-like poly (p-phenylenediamine) (PpPD) microcrystal was prepared under mild conditions, which was successfully applied to the visual detection of Co2+in vitro and in tissue based on the extinction and light scattering features owing to the special etching effect of Co2+ on the surface of the leaf-like microcrystal.
Co-reporter:Yan Zhang, Yue Liu, Shu Jun Zhen and Cheng Zhi Huang
Chemical Communications 2011 - vol. 47(Issue 42) pp:NaN11720-11720
Publication Date(Web):2011/09/27
DOI:10.1039/C1CC14491J
A long range resonance energy transfer (LrRET) strategy for label-free and sensitive DNA detection is outlined by introducing graphene oxide (GO) as an efficient signal-to-background enhancer, giving a limit of determination (3σ) of 0.31 nM.
Co-reporter:Yi Juan Long, Yuan Fang Li, Yue Liu, Jia Jia Zheng, Jie Tang and Cheng Zhi Huang
Chemical Communications 2011 - vol. 47(Issue 43) pp:NaN11941-11941
Publication Date(Web):2011/10/05
DOI:10.1039/C1CC14294A
Mercury-stimulated peroxidase mimetic activity of gold nanoparticles was presented, with which a sensitive label-free colorimetric method for Hg2+ was developed.
Co-reporter:Yi Wang, Yuan Fang Li, Jian Wang, You Sang and Cheng Zhi Huang
Chemical Communications 2010 - vol. 46(Issue 8) pp:NaN1334-1334
Publication Date(Web):2010/01/06
DOI:10.1039/B921464J
We report a novel, simple, highly selective and versatile approach for the end-to-end assembly of gold nanorods (GNRs) by means of the specific molecular recognition between thymine-rich (T-rich) oligonucleotides and mercury(II).
Co-reporter:Li Zhang, Shu Jun Zhen, You Sang, Jing Yun Li, Yi Wang, Lei Zhan, Li Peng, Jian Wang, Yuan Fang Li and Cheng Zhi Huang
Chemical Communications 2010 - vol. 46(Issue 24) pp:NaN4305-4305
Publication Date(Web):2010/05/06
DOI:10.1039/C0CC00231C
We report a novel strategy to fabricate metal nanoparticle/carbon nanotube hybrids with unique plasmon properties as well as biocompatibility and further apply them as efficient dark field light scattering agents for cancer cell imaging.
Co-reporter:Wen Jing Qi, Di Wu, Jian Ling and Cheng Zhi Huang
Chemical Communications 2010 - vol. 46(Issue 27) pp:NaN4895-4895
Publication Date(Web):2010/06/11
DOI:10.1039/C0CC00886A
Melamine can be sensitively detected in aqueous medium through its selective interaction with polythymine (polyTn) modified gold nanoparticles (AuNPs) by forming triple H-bonds, which results in aggregation of the polyTn-stabilized AuNPs, displaying variations of localized plasmon resonance features such as colour change from red to purple and enhanced localized surface plasmon resonance light scattering (LSPR-LS) signals.
Co-reporter:Ping Ping Hu, Li Qiang Chen, Chun Liu, Shu Jun Zhen, Sai Jin Xiao, Li Peng, Yuan Fang Li and Cheng Zhi Huang
Chemical Communications 2010 - vol. 46(Issue 43) pp:NaN8287-8287
Publication Date(Web):2010/09/30
DOI:10.1039/C0CC02600J
An ultra-sensitive detection strategy for prion protein is proposed based on the long range resonance energy transfer (LrRET) from quantum dots (QDs) to the surface of gold nanoparticles (AuNPs), in which process energy donor–acceptor separation distance ranges from 9 to 22 nm.
Co-reporter:Peng Fei Gao, Ming Xuan Gao, Hong Yan Zou, Rong Sheng Li, Jun Zhou, Jun Ma, Qiang Wang, Feng Liu, Na Li, Yuan Fang Li and Cheng Zhi Huang
Chemical Science (2010-Present) 2016 - vol. 7(Issue 8) pp:NaN5483-5483
Publication Date(Web):2016/04/25
DOI:10.1039/C6SC01055E
The plasmon-induced light concentration (PILC) effect, which has been supposed to be responsible for lots of linear and nonlinear enhanced optical signals such as Raman and high-harmonic generation, is hard to directly observe. Herein, we developed a scattered light based composite-field microscopy imaging (iCFM) system by coupling the oblique and vertical illumination modes, which were adopted in dark- and bright-field microscopy imaging systems, respectively, and through which iCFM system monochromatic background (MCB) images are available, to directly observe the PILC effect in far-field scattering microscopy imaging. Owing to the PILC effect, the scattering signal gain of plasmonic nanoparticles was found to be larger than that of the background, and the imaging visibility of plasmonic nanoparticles was improved by 2.4-fold for silver nanoparticles (AgNPs) and 1.6-fold for gold nanorods (AuNRs). Successful observation of the PILC effect visually together with application in enhanced visibility in cancer cell imaging by this composite illumination system might open an exciting prospect of light scattering microscopy imaging techniques with largely increased visibility.
Co-reporter:Ting Ting Wang, Jing Lan, Yue Zhang, Zhu Lian Wu, Chun Mei Li, Jian Wang and Cheng Zhi Huang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 30) pp:NaN6384-6384
Publication Date(Web):2015/06/30
DOI:10.1039/C5TB00824G
Synergistic therapy has become a potential treatment in the battle against disease. In this work, we developed a novel versatile folate targeted system for cancer cells with the combination of chemotherapy and phototherapy by using mesoporous silica nanoparticles (MSNs) as a drug loading carrier, in which reduced graphene oxide (rGO) gated the MSNs by pH responsive detachment. That is, rGO herein acts not only for gating control of the drug release but also for near-infrared photothermal therapy. With this drug loading system, high photothermal conversion efficiency and excellent doxorubicin (DOX) loading capacity have been achieved, making the DOX loaded MSN@rGO-FA (DOX@MSN@rGO-FA) nanocomposites able to kill 68% of HEp-2 cells in synergistic therapy, as compared with 54% in photothermal therapy and 33% in chemotherapy, respectively, illustrating that a synergistic therapy strategy using this newly developed versatile drug loading system is much more efficient as evaluated in vitro.
Co-reporter:Wen Long Li, Shao Qing Lie, Yu Qing Du, Xiao Yan Wan, Ting Ting Wang, Jian Wang and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 40) pp:NaN7033-7033
Publication Date(Web):2014/08/20
DOI:10.1039/C4TB01099J
A facile aqueous chemical approach is developed for one-pot synthesis of the nanocomposites of heavily doped semiconductor nanoparticles (Cu2−xSe NPs) and reduced graphene oxide (rGO) at room temperature, wherein the reduction of GO and the in situ growth of Cu2−xSe NPs on rGO sheets occur simultaneously. The as-prepared Cu2−xSe/rGO nanocomposites exhibit a well-defined near-infrared (NIR) localized surface plasmon resonance (LSPR), which arises from free carriers (holes) and could be tuned from 1360 to 1050 nm by varying the reaction time, owing to the increase of the free carrier density in the valence band of Cu2−xSe NPs. This approach not only offers an efficient strategy to synthesize the self-doped Cu2−xSe/rGO nanocomposites with strong and tunable NIR absorption, but also develops new light scattering nanoprobes with good biocompatibility as well as unique optical properties for in vitro cellular dark-field microscopic imaging (iDFM).
Co-reporter:Zhu Lian Wu, Pu Zhang, Ming Xuan Gao, Chun Fang Liu, Wei Wang, Fei Leng and Cheng Zhi Huang
Journal of Materials Chemistry A 2013 - vol. 1(Issue 22) pp:NaN2873-2873
Publication Date(Web):2013/04/23
DOI:10.1039/C3TB20418A
Nitrogen-doped carbon dots (CDs) have attracted great interest due to their extraordinary properties, especially their enhanced emission efficiency, and thus a facile synthesis of nitrogen-doped CDs with high emission efficiency is critical for practical applications. To improve the emission efficiency of CDs, herein we employed Bombyx mori silk, which has high nitrogen content, as a raw material to prepare photoluminescent nitrogen-doped carbon dots through one-pot hydrothermal synthesis, and found that the as-prepared CDs have a photoluminescence (PL) quantum yield of 13.9%, and display amphoteric properties depending on the pH, are highly photostable, have low toxicity and are suitable for bioimaging.
Co-reporter:Jun Wang, Peng Pei Gao, Xiao Xi Yang, Ting Ting Wang, Jian Wang and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 27) pp:NaN4386-4386
Publication Date(Web):2014/04/23
DOI:10.1039/C4TB00221K
In this study, a targeted cancer therapy imaging and sensing system is designed based on doxorubicin (DOX)-loaded green fluorescent mesoporous silica nanoparticles (FMSN) conjugated with folic acid (FA), by linking with α-amine-ω-propionic acid hexaethylene glycol (NH2-PEG-COOH). An in situ formation method is adopted to prepare luminescent MSNs, which then act as the donor for the fluorescence resonance energy transfer (FRET), as their emission at 500 nm overlaps with the absorption of the acceptor DOX at 485 nm. NH2-PEG-COOH is conjugated to the outer surface of the FMSN at one end and modified by folic acid at the other, so that the formed mesoporous silica composite has the merits of fluorescence imaging, mesoporous nanostructure for drug loading, receptor-mediated targeting and real-time monitoring of intracellular drug release. It was found that the FA-grafted and PEGlated nanocomposite has excellent biocompatibility towards Hep2 cells, and that the cytotoxicity of the loaded-DOX nanoparticles, containing the folate targeting units in the folate-receptor-rich Hep2 cancer cells, is higher than that without folate targeting units, under the same conditions. When the resultant nanoparticles enter into the cells, the green fluorescence of FMSN gradually recovers along with the release of DOX, to achieve the purpose of real-time monitoring of intracellular drug release.
Co-reporter:Jian Wang, Ting Ting Wang, Peng Fei Gao and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 48) pp:NaN8465-8465
Publication Date(Web):2014/10/29
DOI:10.1039/C4TB01263A
Biomolecules perform vital functions in biology. These functional biomolecules with diverse modifications hold great promise for further applications in bioanalysis and cancer therapy. However, these functional biomolecules face challenges, especially in the field of drug delivery for cancer therapy. For example, functional biomolecules are typically unstable when taken up by cells, as they are easily digested by enzymes. To address this obstacle, nanomaterials have been employed as drug carriers or vehicles, which are powerful nanoplatforms for imaging and cancer treatment. Multifunctionality of these nanoplatforms offers great advantages over conventional reagents, including targeting to a diseased site to minimize systemic toxicity, and the ability to solubilize hydrophobic or labile drugs to improved pharmacokinetics. In this review, we summarize typical functional biomolecule-conjugated nanomaterials for targeting drug delivery. Under the appropriate conditions, targeted drug delivery can be achieved from a high density of biomolecules that are bound to the surface of nanomaterials, resulting in a high affinity for the targets. The high density of biomolecules then leads to a high local concentration, being able to prevent degradation by enzymes. Furthermore, biomolecule–nanomaterial conjugates have been identified to enter cells more easily than free biomolecules, and controllable drug release can then be obtained by a response to a stimulus, such as redox, pH, light, thermal, enzyme-trigged strategies. Now and in the future, with the development of artificial biomolecules as well as nanomaterials, targeted drug delivery based on elegant biomolecule–nanomaterial conjugation approaches is expected to achieve great versatility, additional functions, and further advances.
Co-reporter:Li Zhang, Sai Jin Xiao, Lin Ling Zheng, Yuan Fang Li and Cheng Zhi Huang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 48) pp:NaN8565-8565
Publication Date(Web):2014/10/06
DOI:10.1039/C4TB01310G
Fluorescent semiconductor quantum dot–graphene oxide (QD–GO) nanocomposites with unique optical properties can be prepared by a facile decoration of aptamer-labelled CdSe@ZnS QDs on GO nanosheets. The formation of such nanocomposites is based on the π–π stacking between the DNA bases on the QD surfaces and the GO. TEM and AFM were used to study the morphologies and distribution of the QDs on the GO surfaces. Steady-state fluorescence spectra, time-resolved fluorescence experiments and fluorescence imaging were employed to study the optical properties of the prepared aptamer-QD–GO nanocomposites. Furthermore, we investigate the potential applications of the nanocomposites in bio-imaging and cell-targeted drug delivery. The QDs decorated on the surfaces of GO could serve as fluorescent labeling probes for tracking the intracellular transport, while the GO combined with the aptamer conjugated on the outside of the nanocomposites facilitates the targeted drug delivery with enhanced loading capability. It is believed that the present aptamer-QD–GO nanocomposite-based nanomedicine would permit the development of more effective means for diagnosing and treating malignancies compared to the currently used methods.
Co-reporter:Peng Fei Gao, Lin Ling Zheng, Li Jiao Liang, Xiao Xi Yang, Yuan Fang Li and Cheng Zhi Huang
Journal of Materials Chemistry A 2013 - vol. 1(Issue 25) pp:NaN3208-3208
Publication Date(Web):2013/05/07
DOI:10.1039/C3TB00026E
A new type of coordination polymer sphere prepared by combining 1,1′-(1,4-butanediyl)bis(imidazole) (bbi) and ferrous ions has been demonstrated as a targeted delivery system for in situ encapsulating anticancer drugs. These stable coordination polymer spheres can be fabricated simply by a deposition method. Drugs, doxorubicin hydrochloride (DOX·HCl) for example, can be easily in situ encapsulated by simply mixing the drug with bbi ligand through the deposition method and results in a high drug loading efficiency up to 98% and a drug loading content of nearly 40%, which is remarkably high for not only metal–organic but also other materials. A noticeable feature of the drug loaded coordination polymer spheres is that they show sustainable drug release for several days due to their superior stability, and are sensitive to external pH owing to the coordination bonds. The drug can be released faster in mild acidic conditions in comparison to physiological acidity. By conjugating folic acid to the surface of the coordination polymer spheres, the vehicles can be taken up selectively by cancer cells through cell surface receptor-mediated mechanisms. Cell viability experiments with HeLla cells demonstrated the low toxicity of the delivery vehicles and the good anticancer efficacy of the drug-loaded coordination polymer spheres.
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![4-([2,2':6',2''-Terpyridin]-4'-yl)benzoic acid](/data/chemimg/104300/158014-74-5.png)
![4-([2,2':6',2''-Terpyridin]-4'-yl)benzoic acid](/data/chemimg/104300/158014-74-5_b.png)
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![Cyclohexanone, 2-[(2,4-dichlorophenyl)methylene]-](http://img.cochemist.com/ccimg/116900/116897-66-6_b.png)
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