Co-reporter:Ling-Xia Zuo, Wen-Jing Wang, Rong-Bin Song, Jing-Jing Lv, Li-Ping Jiang, and Jun-Jie Zhu
ACS Sustainable Chemistry & Engineering November 6, 2017 Volume 5(Issue 11) pp:10275-10275
Publication Date(Web):September 27, 2017
DOI:10.1021/acssuschemeng.7b02291
The demand on the highly efficient and low-cost cathodic electrocatalysts for commercialization of fuel cells is rapidly increasing. One smart route for obtaining these ideal electrocatalysts is extracting active carbon materials from natural and cheap biomass waste. Here, we prepared a novel nitrogen self-doped porous graphitic carbon nanosheets (NPGCNs-NaCl) derived from a nitrogen-rich pruning of Lycium barbarum L. using NaCl crystal as intercalation agent. The as-obtained NPGCNs-NaCl possessed porous structure, large surface area, increased content of nitrogen and high graphitic carbon, and thus making it with high electrocatalytic activity for oxygen reduction reaction (ORR). Most importantly, significantly enhanced stability and tolerance against methanol were observed compared with commercial Pt/C catalyst in alkaline solution. This work is believed to open a new avenue for manufacturing advanced and low-cost ORR electrocatalysts in fuel cells from biomass waste.Keywords: NaCl crystal intercalation; Nitrogen self-doped porous graphitic carbon nanosheets; Oxygen reduction reaction; Pruning of Lycium barbarum L.;
Co-reporter:Ling-Xia Zuo, Li-Ping Jiang, E.S. Abdel-Halim, Jun-Jie Zhu
Ultrasonics Sonochemistry 2017 Volume 35(Part A) pp:219-225
Publication Date(Web):March 2017
DOI:10.1016/j.ultsonch.2016.09.021
Porous MnO2 as a non-noble metal oxygen reduction reaction (ORR) electrocatalyst was prepared by a simple sonochemical route. The as-prepared porous MnO2 exhibited higher electrocatalytic activity, superior stability and better methanol tolerance than commercial Pt/C catalyst in alkaline media. Furthermore, the ORR proceeded via a nearly four-electron pathway. Cyclic voltammetry (CV) and rotating-disk electrode (RDE) measurements verified that the ORR enhancement was attributed to the porous structure and good dispersity, which facilitated sufficient transport of ions, electrons, O2 and other reactants in the process of ORR. The results indicated that a facile and feasible sonochemical route could be used to prepare highly active porous MnO2 electrocatalyst for ORR, which might be promising for direct methanol fuel cells.
Co-reporter:Ling-Xia Zuo, Li-Ping Jiang, Jun-Jie Zhu
Ultrasonics Sonochemistry 2017 Volume 35(Part B) pp:681-688
Publication Date(Web):March 2017
DOI:10.1016/j.ultsonch.2016.02.006
For the alkaline fuel cell cathode reaction, it is very essential to develop novel catalysts with superior catalytic properties. Here, we report the synthesis of highly active and stable MoS2/Pd composites for the oxygen reduction reaction (ORR), via a simple, eco-friendly sonochemical method. The bulk MoS2 was first transformed into single and few layers MoS2 nanosheets through ultrasonic exfoliation. Then the exfoliated MoS2 nanosheets served as supporting materials for the nucleation and further in-situ growth of Pd nanoparticles to form MoS2/Pd composites via ultrasonic irradiation. Cyclic voltammetry and rotating disk voltammetry measurements demonstrate that as-prepared MoS2/Pd composites which provides a direct four-electron pathway for the ORR, have better electrocatalytic activity, long-term operation stability than commercial Pt/C catalyst. We expect that the present work would provide a promising strategy for the development of efficient oxygen reduction electrocatalyst. In addition, this study can also be extended to the preparation of other hybrid with desirable morphologies and functions.
Co-reporter:Fei Zhou, Tingting Zheng, E. S. Abdel-Halim, Liping Jiang and Jun-Jie Zhu
Journal of Materials Chemistry A 2016 vol. 4(Issue 17) pp:2887-2894
Publication Date(Web):29 Mar 2016
DOI:10.1039/C6TB00438E
A novel multifunctional nanoplatform was designed based on the combination of silver nanoparticles (AgNPs) with nucleolin-targeted and doxorubicin (Dox)-loaded manganese dioxide (MnO2) nanosheets to induce enhanced cancer cell apoptosis. MnO2 nanosheets fabricated on the surface of AgNPs served as efficient fluorescence quenchers of Dox. After being internalized into cancer cells, the fluorescence of Dox could be turned on gradually by intracellular glutathione (GSH) which reduces MnO2 into Mn2+ to release Dox. The synergetic effects of AgNP-induced apoptosis and subsequent Dox delivery resulted in enhanced cancer cell apoptosis. Annexin V-FITC/PI double staining, mitochondrial membrane potential (MMP) detection and reactive oxygen species (ROS) detection demonstrated the specific enhanced apoptosis of cancer cells. In this way, the novel nanoprobes can be used as promising theranostic agents for specific cancer therapy.
Co-reporter:Ying Zhou, Jie Ding, Tingxizi Liang, E. S. Abdel-Halim, Liping Jiang, and Jun-Jie Zhu
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 10) pp:6423
Publication Date(Web):February 24, 2016
DOI:10.1021/acsami.6b01031
Fluorescent nanosensors have been widely applied in recognition and imaging of bioactive small molecules; however, the complicated surface modification process and background interference limit their applications in practical biological samples. Here, a simple, universal method was developed for ratiometric fluorescent determination of general small molecules. Taking superoxide anion (O2•–) as an example, the designed sensor was composed of three main moieties: probe carrier, rattle-type silica colloidal particles (mSiO2@hmSiO2 NPs); reference fluorophore doped into the core of NPs, fluorescein isothiocyanate (FITC); fluorescent probe for superoxide anion, hydroethidine (HE). In the absence of O2•–, the sensor just emitted green fluorescence of FITC at 518 nm. When released HE was oxidized by O2•–, the oxidation product exhibited red fluorescence at 570 nm and the intensity was linearly associated with the concentration of O2•–, while that of reference element remained constant. Accordingly, ratiometric determination of O2•– was sensitively and selectively achieved with a linear range of 0.2–20 μM, and the detection limit was calculated as low as 80 nM. Besides, the technique was also successfully applied for dual-emission imaging of O2•– in live cells and realized visual recognition with obvious fluorescence color change in normal conditions or under oxidative stress. As long as appropriate reference dyes and sensing probes are selected, ratiometric biosensing and imaging of bioactive small molecules would be achieved. Therefore, the design could provide a simple, accurate, universal platform for biological applications.Keywords: bioactive small molecules; FITC@mSiO2@hmSiO2; hydroethidine; ratiometric fluorescent sensor; superoxide anion
Co-reporter:Shanhu Liu, Ziyi Zhang, Shiwei Zhou, Li-Ping Jiang and Jun-Jie Zhu
Analyst 2016 vol. 141(Issue 2) pp:567-569
Publication Date(Web):19 Oct 2015
DOI:10.1039/C5AN01780G
An electrochemical-TUNEL method was developed for a cell sensor. A 3-D bio-interface based on CNT@PDA–FA was employed in the cytosensor, which significantly improved the cell capture. By coupling with a QD-based nanoprobe and electrochemical stripping analysis, the cytosensor exhibited attractive performance for detection of apoptotic cells.
Co-reporter:Tingting Zheng, Jiaju Fu, Liping Jiang, Jun-Jie Zhu
Journal of Electroanalytical Chemistry 2016 Volume 781() pp:418-422
Publication Date(Web):15 November 2016
DOI:10.1016/j.jelechem.2016.10.044
•A robust competitive electrochemical and colorimetric cytosensing platform was developed for detection of acute leukemia cells.•The dual mode sensing strategy allows for ultrasensitive acute leukemia cytosensing with a detection limit as low as ~ 4 cells and a wide linear response range from 102 to 107 cells per mL.•This electrochemical and colorimetric cytosensing approach holds great promise as a new point-of-care diagnostic tool for early detection of human acute leukemia.•This cytosensing platform may be readily expanded to multiplex cytosensing of other cancer cells.Selective and reliable method is of vital importance for acute leukemia detection. In this work, a robust competitive electrochemical and colorimetric cytosensing platform for detection of acute leukemia cells was developed with high sensitivity, selectivity, acceptable rapidity and excellent extensibility. The joint effects of the high catalytic activity of horseradish peroxidase (HRP)-mimiking DNAzyme toward H2O2 reduction and the excellent competing reaction contributed to the greatly enhanced sensitivity. Such a dual mode sensing strategy allows for ultrasensitive acute leukemia cytosensing with a detection limit as low as ~ 4 cells and a wide linear response range from 102 to 107 cells per mL. This electrochemical and colorimetric cytosensing approach holds great promise as a new point-of-care diagnostic tool for early detection of human acute leukemia and may be readily expanded to multiplex cytosensing of other cancer cells.
Co-reporter:Qianhao Min, Siyuan Li, Xueqin Chen, E. S. Abdel-Halim, Li-Ping Jiang, and Jun-Jie Zhu
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 18) pp:9563
Publication Date(Web):March 25, 2015
DOI:10.1021/acsami.5b01006
Global characterization and in-depth understanding of phosphoproteome based on mass spectrometry (MS) desperately needs a highly efficient affinity probe during sample preparation. In this work, a ternary nanocomposite of magnetite/ceria-codecorated titanoniobate nanosheet (MC-TiNbNS) was synthesized by the electrostatic assembly of Fe3O4 nanospheres and in situ growth of CeO 2 nanoparticles on pre-exfoliated titanoniobate and eventually utilized as the probe and catalyst for the enrichment and dephosphorylation of phosphopeptides. The two-dimensional (2D) structured titanoniobate nanosheet not only promoted the efficacy of capturing phosphopeptides with enlarged surface area, but also functioned as a substrate for embracing the magnetic anchor Fe3O4 to enable magnetic separation and mimic phosphatase CeO2 to produce identifying signatures of phosphopeptides. Compared to single-component TiNbNS or CeO2 nanoparticles, the ternary nanocomposite provided direct evidence of the number of phosphorylation sites while maintaining the enrichment efficiency. Moreover, by altering the on-sheet CeO2 coverage, the dephosphorylation activity could be fine-tuned, generating continuously adjustable signal intensities of both phosphopeptides and their dephosphorylated tags. Exhaustive detection of both mono- and multiphosphorylated peptides with precise counting of their phosphorylation sites was achieved in the primary mass spectra in the cases of digests of standard phosphoprotein and skim milk, as well as a more complex biological sample, human serum. With the resulting highly informative mass spectra, this multifunctional probe can be used as a promising tool for the fast and comprehensive characterization of phosphopeptides in MS-based phosphoproteomics.Keywords: 2D nanosheet; dephosphorylation; enrichment; phosphopeptide; ternary nanocomposite;
Co-reporter:Fang-Fang Cheng, Ting-Ting He, Hai-Tiao Miao, Jian-Jun Shi, Li-Ping Jiang, and Jun-Jie Zhu
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 4) pp:2979
Publication Date(Web):January 14, 2015
DOI:10.1021/am508690x
MicroRNAs (miRNAs) have emerged as new candidates as diagnostic and prognostic biomarkers for the detection of a wide variety of cancers; thus, sensitive and selective detection of microRNAs is significant for early-phase cancer diagnosis and disease prevention. A novel and simple electrochemical miRNA biosensor was developed using Cd2+-modified titanium phosphate nanoparticles as signal unit, two DNA as capture probes, and Ru(NH3)63+ as electron transfer mediator. Large quantities of cadmium ions were mounted in titanium phosphate spheres to output the electrochemical signal. Because of the presence of Ru(NH3)63+ molecules that interacted with DNA base-pairs as electron wire, the electrochemical signal significantly increased more than 5 times. This approach achieved a wide dynamic linear range from 1.0 aM to 10.0 pM with an ultralow limit detection of 0.76 aM, exerting a substantial enhancement in sensitivity. Moreover, the proposed biosensor was sufficiently selective to discriminate the target miRNAs from homologous miRNAs and could be used for rapid and direct analysis of miRNAs in human serum. Therefore, this strategy provides a new and ultrasensitive platform for miRNA expression profiling in biomedical research and clinical diagnosis.Keywords: electrochemical biosensor; electron transfer; microRNAs; titanium phosphate
Co-reporter:Hongying Liu, Zhimei He, Li-Ping Jiang, and Jun-Jie Zhu
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 8) pp:4913
Publication Date(Web):February 11, 2015
DOI:10.1021/am508994w
A facile and rapid strategy was developed for the synthesis of ultrabright luminescent carbon nanodots (CDs) with tunable wavelength from 464 to 556 nm by introducing glutaraldehyde into the precursor solution under microwave irradiation. The fluorescence properties, including excitation and emission wavelength, quantum yield, and size of the CDs, were adjusted by changing the amount of glutaraldehyde and poly(ethylenimine). Several methods such as high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and dynamic light scattering, UV–vis, fluorescence, and Fourier transform infrared spectroscopy were employed to study the morphology and the properties of CDs. The luminescence mechanism was also discussed. In addition, confocal microscopy imaging revealed that the as-prepared CDs could be used as effective fluorescent probes in the cell imaging without obvious cytotoxicity. Moreover, a novel sensor for the detection of Co2+ was proposed on the basis of Co2+-induced fluorescence quenching. These superior properties demonstrated the potential application of the CDs in cellular imaging and ion sensing.Keywords: carbon nanodots; Co2+; imaging; microwave; wavelength-tunable
Co-reporter:Qingming Shen, Li Han, Gaochao Fan, Jian-Rong Zhang, Liping Jiang, and Jun-Jie Zhu
Analytical Chemistry 2015 Volume 87(Issue 9) pp:4949
Publication Date(Web):April 14, 2015
DOI:10.1021/acs.analchem.5b00679
A novel “signal-on” photoelectrochemical (PEC) biosensor for sensitive detection of human T-cell lymphotropic virus type II (HTLV-II) DNA was developed on the basis of enzymatic amplification coupled with terminal deoxynucleotidyl transferase (TdT)-mediated extension strategy. The intensity of the photocurrent signal was proportional to the concentration of the HTLV-II DNA-target DNA (tDNA) by dual signal amplification. In this protocol, GR-CdS:Mn/ZnS nanocomposites were used as photoelectric conversion material, while pDNA was used as the tDNA recognizing unit. Moreover, the TdT-mediated extension and the enzymatic signal amplification technique were used to enhance the sensitivity of detection. Using this novel dual signal amplification strategy, the prototype of PEC DNA sensor can detect as low as ∼0.033 fM of HTLV-II DNA with a linear range of 0.1–5000 fM, with excellent differentiation ability even for single-base mismatches. This PEC DNA assay opens a promising platform to detect various DNA targets at ultralow levels for early diagnoses of different diseases.
Co-reporter:Jie Ding, Ying Zhou, Jingjing Li, Liping Jiang, Zhiwei He, and Jun-Jie Zhu
Analytical Chemistry 2015 Volume 87(Issue 24) pp:12290
Publication Date(Web):November 24, 2015
DOI:10.1021/acs.analchem.5b03580
The high-performance and noninvasive screening of heterogeneous tumor subtypes in vivo is particularly desirable for the diagnosis and symptomatic treatment of cancer. Therefore, we report a near-infrared (NIR) fluorescence tracer “smartly identified HER2” (SI-HER2) for rapid, accurate, and highly specific screening of HER2 overexpressed breast cancer. An antibody against HER2 protein receptor, EP1045Y, was conjugated with NIR emitting CdSeTe/CdS/ZnS QDs via polyhistidine-driven self-assembly approach. The further adsorption of black hole quencher 3 on antibody enabled a “turn on” fluorescence response of the fluorescence tracer to HER2 protein receptor. Aside from the capability of differentiating the HER2 overexpressed MCF-7 cells from its counterparts, the fluorescence tracer can also accurately and rapidly identify the HER2 overexpressed breast tumor subtype in two tumors-bearing mouse model, providing a platform for the investigation of advanced pathways to distinguish the different breast cancer subtypes.
Co-reporter:Shiwei Zhou;Yingying Wang;Ming Zhao; Li-Ping Jiang; Jun-Jie Zhu
ChemPhysChem 2015 Volume 16( Issue 13) pp:2826-2835
Publication Date(Web):
DOI:10.1002/cphc.201500489
Abstract
A macroporous TiO2 film (M-TiO2), which was prepared by burning off the polystyrene microsphere (PS) template from a PS/TiO2 composite film, can provide a large active surface, improve electron-transport performance, and increase the photocurrent. Furthermore, core–shell–shell CdSeTe@CdS@ZnS quantum dots (QDs) were introduced to sensitize the M-TiO2 film, which can efficiently broaden the absorption spectra range, separate and transfer charge carriers, reduce recombination loss, and improve photovoltaic response, with a sensitization shell of CdS and a passivation shell of ZnS. A multisignal-amplified photoelectrochemical platform was fabricated by further modifying this film with a combination of biotin–DEVD–peptide (Biotin–Gly–Asp–Gly–Asp–Glu–Val–Asp–Gly–Cys) (which is specifically cleaved by caspase-3) and streptavidin-labeled alkaline phosphatase (SA-ALP). Under the enzymatic catalysis of ALP with the substrate 2-phospho-L-ascorbic acid trisodium salt (AAP), ascorbic acid (AA) was generated as a better electron donor, leading to increased photocurrent output. The activity of caspase-3, which depends on the amount of residual peptide on the electrode, was inversely proportional to the amount of AA. By monitoring the variation of photocurrent caused by AA, caspase-3 activity and the therapeutic effect of nilotinib (a special medicine of chronic myeloid leukemia, CML) were indirectly detected and evaluated. The photoelectrochemical platform can be used as a potential evaluation system for monitoring caspase-3 activity and drug effects.
Co-reporter:Qingming Shen, Li Han, Gaochao Fan, E.S. Abdel-Halim, Liping Jiang, Jun-Jie Zhu
Biosensors and Bioelectronics 2015 Volume 64() pp:449-455
Publication Date(Web):15 February 2015
DOI:10.1016/j.bios.2014.09.044
•This work developed a sensitive photoelectrochemical assay for DNA methyltransferase (MTase) activity.•The assay is based on the combination of the exciton energy transfer effect with site-specific cleavage of restriction endonuclease.•This method showed high sensitivity with detection limit of ~0.0042 U/mL of M.SssI MTase.•The assay could be also used for the screening of the inhibitors of MTase.Highly sensitive DNA methyltransferase (MTase) activity and inhibitor screening photoelectrochemical (PEC) assay was developed based on the exciton energy transfer (EET) effect coupled with site-specific cleavage of restriction endonuclease (HpaII). The assay was designed by integrating the Au nanoparticles (NPs) labeled probe DNA (pDNA-Au) with CdSe quantum dots (QDs). The strong EET effect between Au NPs and CdSe QDs resulted in the dramatic decrease of photocurrent signal. The pDNA carried a sensing region for specifically recognizing target DNA (tDNA) and hybridizing with it to form a DNA duplex. With the site-specific cleavage of HpaII, the DNA duplex could be cleaved and Au NPs would be released, which broke the EET and resulted in the restoration of photocurrent signal. However, when the DNA duplex was methylated by M.SssI MTase, this cleavage of HpaII was blocked, and therefore the unbroken EET effect kept the lower photocurrent signal. That was, the restored photocurrent was inversely proportional to the MTase activity. Based on this strategy, the PEC assay could determine as low as ~0.0042 U/mL of M.SssI MTase with a linear range from 0.01 to 150 U/mL. In addition, the assay could be used for the screening of the inhibitors of MTase. This PEC assay provides a promising platform for monitoring the activity and inhibition of DNA MTase, and thus shows a great potential in cancer diagnostics and anti-cancer drugs discovery.
Co-reporter:Yujie Ding, Hao Zhu, Xiaoxia Zhang, Jiangang Gao, E. S. Abdel-Halim, Liping Jiang and Jun-Jie Zhu
Nanoscale 2014 vol. 6(Issue 24) pp:14792-14798
Publication Date(Web):09 Oct 2014
DOI:10.1039/C4NR04380D
Upconversion nanophosphors (UCNPs) are extremely useful for analytical applications, since they display a high signal-to-noise ratio, and their photobleaching can be ignored. Herein, a novel upconversion nanocomposite composed of β-cyclodextrin (β-CD) derivative modified UCNPs and rhodamine B (RB) was prepared for the detection of cholesterol (Cho). The upconversion luminescence (UCL) emission can serve as a Cho-sensing signal by an effective fluorescence resonance energy transfer (FRET) process, using UCNPs as the donor and RB as the quencher. The sensor for Cho detection in human serum shows excellent sensitivity and selectivity, which has the potential for clinical applications in the analysis of other biological and environmental samples.
Co-reporter:Ying-Di Zhu, Juan Peng, Li-Ping Jiang and Jun-Jie Zhu
Analyst 2014 vol. 139(Issue 3) pp:649-655
Publication Date(Web):07 Nov 2013
DOI:10.1039/C3AN01987J
A novel fluorescent immunosensor was developed based on the use of CuS nanoparticles (CuS NPs) as labels for the highly sensitive detection of human prostate cancer biomarker prostate specific antigen (PSA). In the presence of CuS NPs, the non-fluorescent substrate o-phenylenediamine could be oxidized into the stable fluorescent product 2,3-diamiophenazine at physiological pH. Throughout the reaction, no other oxidizing agents (e.g. hydrogen peroxide) were needed. The relatively mild oxidation conditions made the immunoassay robust, reliable and facile. The proposed immunoassay exhibited high sensitivity and specificity for the detection of PSA. A linear relationship between the fluorescent signals and the concentration of PSA was obtained in the range of 0.5 pg mL−1 to 50 ng mL−1, with a detection limit of 0.1 pg mL−1 (S/N = 3). The proposed fluorescent immunoassay can be used as a promising platform for the detection of a variety of other biomarkers.
Co-reporter:Juan Peng;Ying-Di Zhu;Xing-Hua Li;E. S. Abdel-Halim
Microchimica Acta 2014 Volume 181( Issue 13-14) pp:1505-1512
Publication Date(Web):2014 October
DOI:10.1007/s00604-014-1193-x
We report on a sensitive electrochemical immunoassay for the prostate specific antigen (PSA). An immunoelectrode was fabricated by coating a glassy carbon electrode with multiwalled carbon nanotubes, poly(dimethyldiallylammonium chloride), CeO2 and PSA antibody (in this order) using the layer-by-layer method. The immunosensor is then placed in a sample solution containing PSA and o-phenylenediamine (OPD). It is found that the CeO2 nanoparticles facilitate the electrochemical oxidation of OPD, and this produces a signal for electrochemical detection of PSA that depends on the concentration of PSA. There is a linear relationship between the decrease in current and the concentration of PSA in the 0.01 to 1,000 pg mL−1 concentration range, and the detection limit is 4 fg mL−1. The assay was successfully applied to the detection of PSA in serum samples. This new differential pulse voltammetric immunoassay is sensitive and acceptably precise, and the fabrication of the electrode is well reproducible.
Co-reporter:Zheng-Zhi Yin, Yongjie Li, Li-Ping Jiang, Rohit Kumar Rana, Jun-Jie Zhu
Analytica Chimica Acta 2013 Volume 781() pp:48-53
Publication Date(Web):5 June 2013
DOI:10.1016/j.aca.2013.04.011
•Haemin-modified iron(II, III) oxide (Fe3O4) nanoparticles were rapidly synthesised.•Magnetic Fe3O4/haemin show electrocatalytic activity towards trichloroacetic acid.•The response of sensor was studied via electrically heated electrodes.Haemin-functionalised magnetic iron(II, III) oxide (Fe3O4) nanoparticles (Fe3O4/haemin) were synthesised by changing the acidity of a solution of the two compounds. The nanoparticles were characterised by transmission electron microscopy, UV–vis absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, measurement of magnetisation, and electrochemical techniques. The properties of both haemin and Fe3O4 were retained. Thus, Fe3O4/haemin nanoparticles exhibited pronounced electrocatalytic activity towards trichloroacetic acid (TCA) like haemin itself. Interestingly, electrocatalytic activity towards TCA was affected by detection temperature, which was controlled via electrically heated carbon paste electrodes. The maximal catalytic current was 5.8 times higher at 60 °C than at room temperature (25 °C). This proposed electrochemical sensor for TCA possessed a linear detection range of 5–80 μM and a detection limit of 0.3 μM at 60 °C.
Co-reporter:Li-Min Liu, Li-Ping Jiang, Fang Liu, Guo-Yuan Lu, E. S. Abdel-Halim and Jun-Jie Zhu
Analytical Methods 2013 vol. 5(Issue 14) pp:3565-3571
Publication Date(Web):07 May 2013
DOI:10.1039/C3AY00038A
In this paper, hemoglobin/DNA/layered double hydroxide composites were fabricated by co-intercalating hemoglobin (Hb) and DNA in the interlayer galleries of Ni–Al layered double hydroxides (Ni–Al LDH) via a delamination-reassembly procedure. The presence of DNA not only remarkably facilitated the intercalation of Hb into the interlayers of the Ni–Al LDH, but also improved the bioactivity of the entrapped Hb. By depositing the Hb/DNA/LDH composite film onto a glassy carbon electrode, a mediator-free biosensor was obtained. Because of the synergistic effect between the LDH host and the co-intercalated DNA guest, the Hb/DNA/LDH composites modified electrode exhibited a fast direct electron transfer with a rate constant, ks, of 6.95 ± 3.31 s−1 and a sensitive electrocatalytic response to H2O2 and NO2− in the linear range of 4.85 × 10−7 to 1.94 × 10−4 M and 2.5 × 10−7 to 3.0 × 10−5 M, respectively. Furthermore, with the protective effect provided by the LDH nanosheets, the electrocatalytic response of the intercalated Hb to H2O2 was retained, even at high temperatures (85 °C) or in the presence of an organic solvent (CH3CN).
Co-reporter:Ling-Ling Li;Jing Ji;Rong Fei;Chong-Zhi Wang;Qian Lu;Jian-Rong Zhang;Jun-Jie Zhu
Advanced Functional Materials 2012 Volume 22( Issue 14) pp:2971-2979
Publication Date(Web):
DOI:10.1002/adfm.201200166
Abstract
With the assistance of microwave irradiation, greenish-yellow luminescent graphene quantum dots (gGQDs) with a quantum yield (QY) up to 11.7% are successfully prepared via cleaving graphene oxide (GO) under acid conditions. The cleaving and reduction processes are accomplished simultaneously using microwave treatment without additional reducing agent. When the gGQDs are further reduced with NaBH4, bright blue luminescent graphene quantum dots (bGQDs) are obtained with a QY as high as 22.9%. Both GQDs show well-known excitation-dependent PL behavior, which could be ascribed to the transition from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) with a carbene-like triplet ground state. Electrochemiluminescence (ECL) is observed from the graphene quantum dots for the first time, suggesting promising applications in ECL biosensing and imaging. The ECL mechanism is investigated in detail. Furthermore, a novel sensor for Cd2+ is proposed based on Cd2+ induced ECL quenching with cysteine (Cys) as the masking agent.
Co-reporter:Li-Na Feng, Juan Peng, Ying-Di Zhu, Li-Ping Jiang and Jun-Jie Zhu
Chemical Communications 2012 vol. 48(Issue 37) pp:4474-4476
Publication Date(Web):16 Mar 2012
DOI:10.1039/C2CC31552A
Porous titanium phosphate (TiP) nanoparticles with high water solubility have been synthesized by using the surfactant sodium dodecyl sulfate (SDS) as the structure-directing agent. The TiP nanoparticles can be functionalized with Cd2+ and can be further used as labels for electrochemical detection of proteins due to their excellent ion-exchange property.
Co-reporter:Li-Na Feng, Zhi-Ping Bian, Juan Peng, Fang Jiang, Guo-Hai Yang, Ying-Di Zhu, Di Yang, Li-Ping Jiang, and Jun-Jie Zhu
Analytical Chemistry 2012 Volume 84(Issue 18) pp:7810
Publication Date(Web):August 22, 2012
DOI:10.1021/ac301438v
A novel multianalyte electrochemical immunoassay was developed for ultrasensitive detection of human cardiopathy biomarkers cardiac troponin I (cTnI) and human heart-type fatty-acid-binding protein (FABP) using metal ion functionalized titanium phosphate nanospheres (TiP-metal ion) as labels. The metal ions could be detected directly through square wave voltammetry (SWV) without metal preconcentration, and the distinct voltammetric peaks had a close relationship with each sandwich-type immunoreaction. The position and size of the peaks reflected the identity and level of the corresponding antigen. The large amount of metal ions loading on the TiP nanospheres greatly amplified the detection signals, and the good biocompatibility of graphene nanoribbons (GONRs) retained good stability for the sandwich-type immunoassay. The proposed immunoassay exhibited high sensitivity and selectivity for the detection of cTnI and FABP. The linear relationships between electrochemical signals and the concentrations of cTnI and FABP were obtained in the range of 0.05 pg/mL–50 ng/mL and 0.05 pg/mL–50 ng/mL, respectively. The detection limits of cTnI and HIgG were 1 and 3 fg/mL (S/N = 3), respectively. Moreover, the immunoassay accurately detected the concentrations of cTnI and FABP in human serum samples, which were demonstrated to have excellent correlations with the standard enzyme linked immunosorbent assay (ELISA) method. The results suggested that the electrochemical immunoassay would be promising in the point-of-care diagnostics application of clinical screening of acute myocardial infarction (AMI) biomarkers.
Co-reporter:Qingming Shen, Shiwei Zhou, Xiaomei Zhao, Li-Ping Jiang, Wenhua Hou and Jun-Jie Zhu
Analytical Methods 2012 vol. 4(Issue 3) pp:619-622
Publication Date(Web):14 Feb 2012
DOI:10.1039/C2AY05781F
Anatase TiO2 nanoparticle–graphene nanocomposites with enhanced direct electrochemistry of hemoglobin and biosensing for H2O2 were synthesized via a facile, one-step approach in aqueous solution at room temperature.
Co-reporter:Juan Peng;Li-Na Feng; Kui Zhang;Dr. Xing-Hua Li;Dr. Li-Ping Jiang; Jun-Jie Zhu
Chemistry - A European Journal 2012 Volume 18( Issue 17) pp:5261-5268
Publication Date(Web):
DOI:10.1002/chem.201102876
Abstract
Fluorescent gold nanoclusters (AuNCs) were incorporated into porous calcium carbonate spheres through electrostatic interaction. The resulting CaCO3/AuNCs hybrid material exhibited interesting properties, such as porous structure, excellent biocompatibility, good water solubility, and degradability. These properties make the CaCO3/AuNCs hybrid material a promising template to assemble horseradish peroxidase/antibody conjugates (HRP-Ab2). By using CaCO3/AuNCs/HRP-Ab2 bioconjugates as probes, a versatile immunosensor was developed for fluorescent and electrochemical detection of the cancer biomarker neuron-specific enolase (NSE). The detection limits of the sensor were 2.0 and 0.1 pg mL−1 for fluorescent and electrochemical detection, respectively. The immunosensor shows high sensitivity and offers an alternative strategy for the detection of other proteins and DNA.
Co-reporter:Jie Xuan, Xiang-dong Jia, Li-Ping Jiang, E.S. Abdel-Halim, Jun-Jie Zhu
Bioelectrochemistry 2012 Volume 84() pp:32-37
Publication Date(Web):April 2012
DOI:10.1016/j.bioelechem.2011.10.007
Gold nanoparticle-assembled capsules (GNACs) with controllable size and tunable morphology were fabricated through a simple two-step mixing procedure. Cationic polyelectrolyte was first induced to self-assemble into spherical aggregates in the presence of multivalent anions. Then, the aggregates served as an effective template for the self-assembly of gold nanoparticles to form size-controllable capsules. By adjusting the quantity of gold nanoparticles, capsules with various morphologies could be obtained. Because of their unique nanoporous features, the capsules with intact shells were further used to load hemoglobin (Hb) for the fabrication of a novel H2O2 biosensor. The results of UV–vis spectroscopy and cyclic voltammetry indicated that the capsules provided a suitable matrix for the immobilization of Hb. Additionally, the resulting biosensor showed a high affinity and good catalytic activity to H2O2. With the advantages of the large surface area, good conductivity and biocompatibility, the GNACs can offer a promising platform for the development of biosensors. Moreover, on the basis of the capsule structure, this material may also be expected to apply in some fields such as drug delivery, medical diagnostics and bio-encapsulation.Highlights►Gold nanoparticle-assembled capsules with controllable size and tunable morphology were fabricated. ►The prepared capsules provided a suitable matrix for the immobilization of hemoglobin. ►The prepared nanocomposites were assembled on the surface of the electrode for the fabrication of a novel H2O2 biosensor.
Co-reporter:Jun Geng;LiPing Jiang;JunJie Zhu
Science China Chemistry 2012 Volume 55( Issue 11) pp:2292-2310
Publication Date(Web):2012 November
DOI:10.1007/s11426-012-4732-5
A clear understanding of the nucleation, growth, coarsening, and aggregation processes of nanomaterials is necessary to enable the preparation of highly controlled nanostructures. Among wet chemical synthetic methods, ultrasound-assisted preparation has become an important tool in material science. The formation and crystal growth mechanism under ultrasound is special compared with other wet chemical synthetic routes. In this review, we discussed the chemical and physical effect of ultrasound and summarized the ultrasonic effect on crystallization. The sonolysis of water and the cavitation-induced microjet impact and shockwave are the two key factors in the sonochemical formation of inorganic nanomaterials. The ultrasonic-assisted Ostwald ripening and oriented attachment processes have been reviewed for the possible crystal growth mechanisms in the fabrication of inorganic nanostructures.
Co-reporter:Jing-Jing Zhang, Yan Liu, Li-Hui Hu, Li-Ping Jiang and Jun-Jie Zhu
Chemical Communications 2011 vol. 47(Issue 23) pp:6551-6553
Publication Date(Web):06 May 2011
DOI:10.1039/C1CC11565K
The proof-of-principle of the integration of electrically heated carbon paste electrode with immunoassay as a potential alternative for ultrasensitive detection of cytokines was demonstrated.
Co-reporter:Lin Dai, Li-Ping Jiang, E.S. Abdel-Halim, Jun-Jie Zhu
Electrochemistry Communications 2011 Volume 13(Issue 12) pp:1525-1528
Publication Date(Web):December 2011
DOI:10.1016/j.elecom.2011.10.008
SiO2 opals template was prepared on Au substrate with vertical deposition technique from highly monodispersed SiO2 particles. After that, Pd was electrodeposited on the SiO2 spheres to fabricate the Pd hollow sphere array after the removal of the SiO2 template with HF solution. The prepared Pd array had a highly ordered structure with huge surface area and exhibited excellent electrocatalytic activity, stability and anti-poison capability for ethanol electrooxidation in alkaline media, which showed that the Pd hollow sphere array could be used as effective electrocatalysts for direct alcohol fuel cells.Highlights►Pd hollow sphere array was successfully prepared with sacrificial template method. ►Pd array exhibited excellent electrocatalytic activity for ethanol electrooxidation. ►Pd array might be used as effective electrocatalysts for direct alcohol fuel cells.
Co-reporter:Juan Peng;Li-Na Feng; Kui Zhang;Jing-Jing Li;Dr. Li-Ping Jiang; Jun-Jie Zhu
Chemistry - A European Journal 2011 Volume 17( Issue 39) pp:10916-10923
Publication Date(Web):
DOI:10.1002/chem.201100899
Abstract
Multifunctional manganese carbonate microspheres with superparamagnetic and fluorescent properties were fabricated and used as biological labels. The Fe3O4@MnCO3 microspheres were synthesized by direct co-precipitation without any linker shell. The Fe3O4@MnCO3 microspheres have uniform size distribution and rough surface, which provides a promising template for the assembly of polyelectrolytes (PEs) and CdTe quantum dots (QDs). A luminescent CdTe shell was observed in Fe3O4@MnCO3@PE-CdTe spheres by confocal fluorescence imaging. With excellent solubility in water and rough surfaces, the multifunctional microsphere offers a friendly microenvironment for immobilization of α-fetoprotein (AFP) antibodies (Ab2) to fabricate Fe3O4@MnCO3@PE-CdTe-Ab2 architecture. By using the Fe3O4@MnCO3@PEs-CdTe-Ab2 bioconjugate as a label, a promising and versatile platform for fluorescence imaging and electrochemical immunosensing of cancer biomarker AFP was developed. The prepared electrochemical immunosensor shows high sensitivity and selectivity with a detection limit of 0.3 pg mL−1.
Co-reporter:Zhengzhi Yin, Yan Liu, Li-Ping Jiang, Jun-Jie Zhu
Biosensors and Bioelectronics 2011 Volume 26(Issue 5) pp:1890-1894
Publication Date(Web):15 January 2011
DOI:10.1016/j.bios.2010.03.025
A novel immunosensor for sensitive detection of tumor necrosis factor α was reported. First of all, gold nanoparticles were uniformly assembled on the surface of poly (styrene-acrylic acid) nanospheres, which was used as the matrix to conjugate alkaline phosphatase (ALP). And then, the obtained composite was used as multi-enzyme functionalized label for immunoassay. Biocompatible polyaniline doped with poly (acrylic acid) was electro-polymerized at the glass carbon electrode to construct the matrix for the immobilization of antibody TNF-α. After the sandwich immunoreaction, the labeled ALP was used to hydrolyze α-naphthyl phosphate to produce the electroactive α-naphthol, which could be amperometrically detected. The results showed that the electrochemical signals were proportional to the logarithm of the antigen concentration in the range of 0.02–200.00 ng/mL with the detection limit of 0.01 ng/mL. The developed immunoassay showed high sensitivity, acceptable stability and reproducibility, which might have potentially broad applications in protein diagnostics and bioassay.
Co-reporter:Jie XUAN, Li-Ping JIANG, Jun-Jie ZHU
Chinese Journal of Analytical Chemistry 2010 Volume 38(Issue 4) pp:513-516
Publication Date(Web):April 2010
DOI:10.1016/S1872-2040(09)60036-0
A nonenzymatic electrochemical sensor for the detection of hydrogen peroxide (H2O2) was developed using a three-dimensional ordered macroporous (3DOM) gold film modified electrode, which was prepared using an inverted colloidal-crystal template technique and electrochemical deposition method. The modified electrode was characterized by cyclic voltammetry (CV). Under the optimized conditions, the sensor showed a wide dynamic range for the detection of H2O2, and the catalytic current was linear with the concentration of H2O2 ranging from 1 × 10−6 M to 5.5 × 10−5 M and 8 × 10−5 M to 1.3 × 10−3 M with a detection limit of 3.3 × 10−7 M estimated at a signal-to-noise ratio of 3. In addition, the sensor exhibited good reproducibility and stability and might have potential applications in the fabrication of nonenzymatic sensor.
Co-reporter:Zhengzhi Yin, Rongjing Cui, Yan Liu, Liping Jiang, Jun-Jie Zhu
Biosensors and Bioelectronics 2010 Volume 25(Issue 6) pp:1319-1324
Publication Date(Web):15 February 2010
DOI:10.1016/j.bios.2009.10.021
A simple strategy for sensitive detection of human IgG using cadmium ions-functionalized polymer nanospheres as the label is presented. The polymer nanosphere consisted of hard poly-styrene core and biocompatible poly (acrylic acid) (PAA) shell. The carboxyl groups of hydrophilic shell were used to chelated with the cadmium ions, and then conjugate with antibody (Ab2) to fabricate metal ions marked bioconjugates as the label in immunoassay. For constructing the matrix of the immunosensor, the PAA-functionalized carbon nanotubes were used to modify disposable screen printed electrodes for the immobilization of antibody (Ab1). After sandwich immunoreaction, differential pulse voltammetry was used to oxidize the conjuncted cadmium for the detection of antigen. The obtained results provided a linear response range from 0.1 to 35.0 pg/mL human IgG with a lower detection limit of 0.06 pg/mL, which is prominently improved in comparison with conventional immunoassay. The usage of the chelation reaction offers a simple and convenient route for the preparation of metallo-immunoassay labels, and also avoids the complicated and time-consuming dissolving of metal component for ultrasensitive determination. This approach is expected to have wide applications in protein diagnostics and bioanalysis in the future.
Co-reporter:Xiaojun Chen, Kui Zhang, Jinjun Zhou, Jie Xuan, Wei Yan, Li-Ping Jiang, Jun-Jie Zhu
Biosensors and Bioelectronics 2010 Volume 25(Issue 5) pp:1130-1136
Publication Date(Web):15 January 2010
DOI:10.1016/j.bios.2009.09.038
A novel type of colloidal carbon sphere array (CSA) was developed for the fabrication of disposable electrochemical immunosensor. The CSA was successfully prepared on indium tin oxide (ITO) substrate in a simple manner and the scanning electron micrograph confirmed that a single-layered arrangement of the carbon spheres with its (1 1 1) plane paralleled the substrate's surface. The CSA modified electrode has a higher surface area and exhibits a more sensitive electrochemical response than a normal carbon-based electrode with the same geometric area. An Immunoglobin A (IgA) immunosensor was constructed by the covalent bonding of IgA antibody molecules with the CSA aided by large numbers of carboxyl groups on the surface of carbon spheres. The immunosensor exhibited a wide linear response to IgA ranging from 0.1 to 200 ng mL−1 by electrochemical impedance spectroscopy (EIS) technique. The detection of IgA levels in three sera obtained from hospital samples showed acceptable accuracy.
Co-reporter:Xing-Hua Li;Lin Dai;Yan Liu;Xiao-Jun Chen;Wei Yan;Jun-Jie Zhu
Advanced Functional Materials 2009 Volume 19( Issue 19) pp:3120-3128
Publication Date(Web):
DOI:10.1002/adfm.200901003
Abstract
A 3D ordered macroporous (3DOM) ionic-liquid-doped polyaniline (IL-PANI) inverse opaline film is fabricated with an electropolymerization method and gold nanoparticles (AuNPs) are assembled on the film by electrostatic adsorption, which offers a promising basis for biomolecular immobilization due to its satisfactory chemical stability, good electronic conductivity, and excellent biocompatibility. The AuNP/IL-PANI inverse opaline film could be used to fabricate an electrochemical impedance spectroscopy (EIS) immunosensor for the determination of Hepatitis B surface antigen (HBsAg). The concentration of HBsAg is measured using the EIS technique by monitoring the corresponding specific binding between HBsAg and HBsAb (surface antibody). The increased electron transfer resistance (Ret) values are proportional to the logarithmic value of the concentration of HBsAg. This novel immunoassay displays a linear response range between 0.032 pg mL−1 and 31.6 pg mL−1 with a detection limit of 0.001 pg mL−1. The detection of HBsAg levels in several sera showed satisfactory agreement with those using a commercial turbidimetric method.
Co-reporter:Xing-Hua Li;Lin Dai;Yan Liu;Xiao-Jun Chen;Wei Yan;Jun-Jie Zhu
Advanced Functional Materials 2009 Volume 19( Issue 19) pp:
Publication Date(Web):
DOI:10.1002/adfm.200990089
Co-reporter:Zhengzhi Yin, Jingjing Zhang, Li-Ping Jiang and Jun-Jie Zhu
The Journal of Physical Chemistry C 2009 Volume 113(Issue 36) pp:16104-16109
Publication Date(Web):August 12, 2009
DOI:10.1021/jp903589a
A poly(N-isopropylacrylamide) (PNIPAm) brush has been successfully fabricated on an indium tin oxide (ITO) film via a simple electrochemical route. The polymer thermoresponsive behavior was investigated with an electrically heated ITO electrode. This kind of electrode demonstrated a rapid response to heating up and down, and the results indicated that the polymer modified interface possessed a characteristic lower critical solution temperature (LCST) and showed ON/OFF switch behavior. Furthermore, the model protein of hemoglobin (Hb) was incorporated into the polymer by a thermal “breathing-in” process. The electrochemical experiments revealed that the film could provide a friendly microenvironment for Hb to promote direct electron transfer. A pair of well-defined redox peaks with a formal potential of −204 mV (verses saturated calomel electrode, SCE) was observed. The redox current of Hb gradually lowered when the prepared electrode was immersed into pH 7.0 PBS at 20 °C, indicating that incorporated Hb could be released from the PNIPAm film, which proved that the approach could provide a potential route in the design of responsive biocompatible surfaces.
Co-reporter:Li-Na Feng, Juan Peng, Ying-Di Zhu, Li-Ping Jiang and Jun-Jie Zhu
Chemical Communications 2012 - vol. 48(Issue 37) pp:NaN4476-4476
Publication Date(Web):2012/03/16
DOI:10.1039/C2CC31552A
Porous titanium phosphate (TiP) nanoparticles with high water solubility have been synthesized by using the surfactant sodium dodecyl sulfate (SDS) as the structure-directing agent. The TiP nanoparticles can be functionalized with Cd2+ and can be further used as labels for electrochemical detection of proteins due to their excellent ion-exchange property.
Co-reporter:Fei Zhou, Tingting Zheng, E. S. Abdel-Halim, Liping Jiang and Jun-Jie Zhu
Journal of Materials Chemistry A 2016 - vol. 4(Issue 17) pp:NaN2894-2894
Publication Date(Web):2016/03/29
DOI:10.1039/C6TB00438E
A novel multifunctional nanoplatform was designed based on the combination of silver nanoparticles (AgNPs) with nucleolin-targeted and doxorubicin (Dox)-loaded manganese dioxide (MnO2) nanosheets to induce enhanced cancer cell apoptosis. MnO2 nanosheets fabricated on the surface of AgNPs served as efficient fluorescence quenchers of Dox. After being internalized into cancer cells, the fluorescence of Dox could be turned on gradually by intracellular glutathione (GSH) which reduces MnO2 into Mn2+ to release Dox. The synergetic effects of AgNP-induced apoptosis and subsequent Dox delivery resulted in enhanced cancer cell apoptosis. Annexin V-FITC/PI double staining, mitochondrial membrane potential (MMP) detection and reactive oxygen species (ROS) detection demonstrated the specific enhanced apoptosis of cancer cells. In this way, the novel nanoprobes can be used as promising theranostic agents for specific cancer therapy.
Co-reporter:
Analytical Methods (2009-Present) 2012 - vol. 4(Issue 3) pp:
Publication Date(Web):
DOI:10.1039/C2AY05781F
Anatase TiO2 nanoparticle–graphene nanocomposites with enhanced direct electrochemistry of hemoglobin and biosensing for H2O2 were synthesized via a facile, one-step approach in aqueous solution at room temperature.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 14) pp:
Publication Date(Web):
DOI:10.1039/C3AY00038A
In this paper, hemoglobin/DNA/layered double hydroxide composites were fabricated by co-intercalating hemoglobin (Hb) and DNA in the interlayer galleries of Ni–Al layered double hydroxides (Ni–Al LDH) via a delamination-reassembly procedure. The presence of DNA not only remarkably facilitated the intercalation of Hb into the interlayers of the Ni–Al LDH, but also improved the bioactivity of the entrapped Hb. By depositing the Hb/DNA/LDH composite film onto a glassy carbon electrode, a mediator-free biosensor was obtained. Because of the synergistic effect between the LDH host and the co-intercalated DNA guest, the Hb/DNA/LDH composites modified electrode exhibited a fast direct electron transfer with a rate constant, ks, of 6.95 ± 3.31 s−1 and a sensitive electrocatalytic response to H2O2 and NO2− in the linear range of 4.85 × 10−7 to 1.94 × 10−4 M and 2.5 × 10−7 to 3.0 × 10−5 M, respectively. Furthermore, with the protective effect provided by the LDH nanosheets, the electrocatalytic response of the intercalated Hb to H2O2 was retained, even at high temperatures (85 °C) or in the presence of an organic solvent (CH3CN).
Co-reporter:Jing-Jing Zhang, Yan Liu, Li-Hui Hu, Li-Ping Jiang and Jun-Jie Zhu
Chemical Communications 2011 - vol. 47(Issue 23) pp:NaN6553-6553
Publication Date(Web):2011/05/06
DOI:10.1039/C1CC11565K
The proof-of-principle of the integration of electrically heated carbon paste electrode with immunoassay as a potential alternative for ultrasensitive detection of cytokines was demonstrated.
