Co-reporter:Yan Zhang, Dongxue Xiang, Bo Tang, and Chun-yang Zhang
Analytical Chemistry October 3, 2017 Volume 89(Issue 19) pp:10439-10439
Publication Date(Web):August 28, 2017
DOI:10.1021/acs.analchem.7b02451
Transcription factors (TFs) modulate the process of gene transcription by binding to specific DNA sequences, and their alteration may cause a variety of diseases. Here, we develop a simple and sensitive method to directly detect TF in crude nuclear extracts using target-actuated isothermal amplification-mediated fluorescence enhancement with fluorescent base 2-aminopurine (2-AP) as the fluorophore. In the presence of TF, its specific binding to the probe prevents the digestion of the probe by exonuclease III (Exo III), initiating the extension reaction to produce DNA duplexes which may be subsequently digested by λ exonuclease to release single-stranded DNAs (ssDNAs) and free 2-AP molecules. Although some excess probes may be partially digested by Exo III, the phosphorothioate modification between two binding sites of the probe may generate a hindrance to preserve the rest of TF-binding probes which may hybridize with the released ssDNAs to initiate new cycles of nicking–digestion–hybridization, generating abundant free 2-AP molecules for significant fluorescence enhancement. Different from the reported amplification strategies, all the TF-binding probes take part in the amplification reaction no matter if they bind with TF or not, greatly improving the detection signal. This method can be used for sensitive detection of NF-κBp50 with a detection limit of 4.11 × 10–4 mg/mL and the screening of potential TF inhibitors as well. Importantly, this method is very simple without the involvement of any external quenchers, extra primers, and templates, and it may be extended to selectively detect various DNA-binding proteins by simply changing the binding-site sequences of the probes.
Co-reporter:Sujuan Ye, Xiaoxiao Li, Menglei Wang, and Bo Tang
Analytical Chemistry May 2, 2017 Volume 89(Issue 9) pp:5124-5124
Publication Date(Web):March 30, 2017
DOI:10.1021/acs.analchem.7b00697
The simultaneous imaging and quantification of multiple intracellular microRNAs (miRNAs) are particularly desirable for the early diagnosis of cancers. However, simultaneous direct imaging with absolute quantification of multiple intracellular RNAs remains a great challenge, particularly for miRNAs, which have significantly different expression levels in living cells. We designed dual-signal switchable (DSS) nanoprobes using the fluorescence-Raman signal switch. The intracellular uptake and dynamic behaviors of the probe are monitored by its fluorescence signal. Meanwhile, real-time quantitative detection of multiple miRNAs is made possible by measurements of the surface-enhanced Raman spectroscopy (SERS) ratios. Moreover, the signal 1:n ratio amplification mode only responds to low-abundance miRNA (asymmetric signal amplification mode) for simultaneous visualization and quantitative detection of significantly different levels of miRNAs in living cells. miR-21 and miR-203 were successfully detected in living MCF-7 cells, in agreement with in vitro results from the same batch of cell lysates. The reported dual-spectrum imaging method promises to offer a new strategy for the intracellular imaging and detection of various types of biomolecules.
Co-reporter:Limin Yang, Yuanyuan Chen, Wei Pan, Hongyu Wang, Na Li, and Bo Tang
Analytical Chemistry June 6, 2017 Volume 89(Issue 11) pp:6196-6196
Publication Date(Web):May 11, 2017
DOI:10.1021/acs.analchem.7b01144
Excess alcohol consumption and the associated development of alcoholic liver disease (ALD) are major public health challenges worldwide. Since patients with the severe stages of ALD no longer benefit from clinical therapies, early warning of ALD holds significant promise for increasing the cure rate of ALD. Herein, we develop a bicolor fluorescent nanoprobe for dynamically monitoring the conversion process of alcohol-induced fatty liver to steatohepatitis in vivo through simultaneous imaging of microRNA 155 and osteopontin mRNA, which are related to fatty liver and steatohepatitis, respectively. The fluorescence imaging results indicate that the nanoprobe can effectively differentiate alcohol-induced fatty liver and steatohepatitis. Moreover, the nanoprobe can monitor the transmutation process of alcohol-induced fatty liver to steatohepatitis and assess the remission effects of N-acetyl cysteine for alcohol-induced liver injury. We anticipate the developed nanoprobe and imaging method can provide new ways for early warning, treatments, and prognosis of ALD.
Co-reporter:Fei Ma, Meng Liu, Bo Tang, and Chun-yang Zhang
Analytical Chemistry June 6, 2017 Volume 89(Issue 11) pp:6182-6182
Publication Date(Web):May 11, 2017
DOI:10.1021/acs.analchem.7b01113
Dysregulation of microRNA expression levels is closely associated with a variety of human diseases, and their rapid and sensitive quantification is essential to clinical diagnosis and therapy. Because of their poor sensitivity, conventional quantification methods are unable to detect low-abundance microRNAs. Alternatively, nucleic acid amplification approaches have been introduced to improve the detection sensitivity, but most of them involve complicated probe design and time-consuming procedures. Herein, we report a simple, rapid, and sensitive fluorescent method for label-free detection of low-abundance microRNAs based on isothermal helicase-dependent amplification. In this assay, the target microRNA may specifically hybridize with the 3′-terminus of the linear probe to form a DNA-microRNA heteroduplex, protecting the probes from exonuclease I digestion. The remaining probes may be subsequently amplified by helicase-dependent amplification, generating an ultrahigh fluorescence signal within 30 min. This assay is very sensitive with a low detection limit of 12.8 fM and exhibits a large dynamical range from 100 fM to 10 nM. Moreover, this assay can discriminate different microRNA family members, and it can be used to absolutely quantify endogenous microRNA of total RNA samples extracted from cancer cells, providing a powerful tool for biomedical research and clinical diagnostics.
Co-reporter:Wen Zhang, Xin Wang, Ping Li, Haibin Xiao, Wei Zhang, Hui Wang, and Bo Tang
Analytical Chemistry June 20, 2017 Volume 89(Issue 12) pp:6840-6840
Publication Date(Web):May 15, 2017
DOI:10.1021/acs.analchem.7b01290
Mitochondrial morphology regulated by fusion and fission processes determines mitochondrial function and cell fate. Some studies showed hyperfused mitochondria could induce apoptosis in cancer cells, but the relevant molecular mechanisms remain elusive. Superoxide (O2•–) and pH play vital roles in mitochondrial dysfunction and apoptosis. Therefore, it is worthwhile to explore if there is an intimate relationship between mitochondrial hyperfusion and simultaneous changes in O2•– and pH levels, which will be helpful to uncover relevant detailed mechanism. For this purpose, we have developed a new reversible two-photon fluorescent probe (CFT) to simultaneously monitor O2•– and pH in 4T1 cells and mice using dual-color imaging. With the assistance of probe, we found that inhibition of Dynamin-related protein 1 (Drp1) could transduce a signal through mitochondrial complexes I and II to enhance the O2•– and pH levels and eventually induced mitohyperfusion and apoptosis in breast cancer cells. Together, these data indicate that CFT provides a robust tool for unveiling the roles of O2•– and pH in signals associated with mitochondrial dysfunction in cells and in vivo.
Co-reporter:Na Li, Meimei Wang, Xiaonan Gao, Zhengze Yu, Wei Pan, Hongyu Wang, and Bo Tang
Analytical Chemistry June 20, 2017 Volume 89(Issue 12) pp:6670-6670
Publication Date(Web):May 24, 2017
DOI:10.1021/acs.analchem.7b00889
Multicomponent quantitative detection in living samples is becoming increasingly important; however, the current detection strategy may cause fluorescence self-quenching and reduce the sensitivity of detection. To solve the problem, we develop a DNA tetrahedral nanoprobe to control the dyes distance for simultaneous detection of multiple analytes. Compared to mesoporous silica nanoparticles based nanoprobes, the DNA tetrahedral nanoprobes display enhanced fluorescence intensities due to partially avoiding the fluorescence resonance energy transfer. Confocal fluorescence images show that the nanoprobes are capable of detecting and visualizing pH and O2•– in living cells under a single wavelength excitation. In an inflammation model for mice, the nanoprobes simultaneously image the down-regulation of pH and up-regulation of O2•–. We expect that the current strategy can provide new opportunities in designing probes for multiplexed detection with reduced self-quenching and enhanced sensitivity.
Co-reporter:Jinye Niu, Jilin Fan, Xu Wang, Yongsheng Xiao, Xilei Xie, Xiaoyun Jiao, Chuanzhi Sun, and Bo Tang
Analytical Chemistry July 5, 2017 Volume 89(Issue 13) pp:7210-7210
Publication Date(Web):June 2, 2017
DOI:10.1021/acs.analchem.7b01425
Biological sensors with simultaneous turn-on signals of fluorescence (FL) and chemiluminescence (CL) triggered by one single species are supposed to integrate spatiotemporally resolved FL imaging with dynamic CL sensing into one luminescent assay. Efficiently increased accuracy can be expected based on complementary information simultaneously obtained from two independent modes, which is crucial in disease detection and diagnosis. However, very few examples can be found to date because of the key challenges in the rational design of sensing structures. Herein, aggregation-induced emission (AIE) was employed to develop a novel organic platform TPE-CLA with simultaneous turn-on FL/CL signals specifically modulated by O2•– in cells, which can be attributed to the activation of AIE resulted from the decreasing solubility after recognition. Using imidazopyrazinone (CLA) as the reactive motif and tetraphenylethene (TPE) as FL/CL enhancing skeleton, TPE-CLA is sensitive enough to image native O2•– in Raw264.7 cells and lipopolysaccharide stimulated O2•– in mice. Endogenous O2•– in HL-7702 cells induced by acetaminophen (APAP) was uninterruptedly monitored for 7200 s with CL and the results were further confirmed by FL imaging. Accordingly, TPE-CLA turns out to be a reliable candidate for real-time and continuous monitoring of endogenous O2•– in live cells. The strategy utilizing AIE to accomplish the FL/CL dual detection is expected to extend the application of AIE as reaction-activated biosensors.
Co-reporter:Yan Zhang, Chen-chen Li, Bo Tang, and Chun-yang Zhang
Analytical Chemistry July 18, 2017 Volume 89(Issue 14) pp:7684-7684
Publication Date(Web):June 16, 2017
DOI:10.1021/acs.analchem.7b01655
DNA glycosylases are responsible for recognition and excision of the damaged bases in the base excision repair pathway, and all mammals express multiple DNA glycosylases to maintain genome stability. However, simultaneous detection of multiple DNA glycosylase still remains a great challenge. Here, we develop a rapid and sensitive fluorescent method for simultaneous detection of human 8-oxoG DNA glycosylase 1 (hOGG1) and uracil DNA glycolase (UDG) using exonuclease-assisted recycling signal amplification in combination with fluorescent bases 2-aminopurine (2-AP) and pyrrolo-dC (P-dC) as the fluorophores. We design a bifunctional DNA probe modified with one 8-oxoG and five uracil bases, which can hybridize with the trigger probes to form a sandwiched DNA substrate for hOGG1 and UDG. In addition, we design 2-AP and P-dC signal probes as the hairpin structures with 2-AP and P-dC in the stems. The presence of hOGG1 and UDG may initiate the signal amplification process by the recycling lambda exonuclease digestion and generates distinct fluorescence signals, with 2-AP indicating the presence of hOGG1 and P-dC indicating the presence of UDG. This method can simultaneously detect multiple DNA glycosylases with the detection limits of 0.0035 U/mL for hOGG1 and 0.0025 U/mL for UDG, and it can even measure DNA glycosylases at the single-cell level. Moreover, this method can be applied for the measurement of enzyme kinetic parameters and the screening of DNA glycosylase inhibitors, holding great potential for further applications in biomedical research and clinical diagnosis.
Co-reporter:Juan Hu, Yueying Li, Ying Li, Bo Tang, and Chun-yang Zhang
Analytical Chemistry December 5, 2017 Volume 89(Issue 23) pp:12992-12992
Publication Date(Web):November 8, 2017
DOI:10.1021/acs.analchem.7b04065
Protein glycosylation is a ubiquitous post-translational modification that plays crucial roles in modulating biological recognition events in development and physiology. Human O-GlcNAc transferase (OGT) is an intracellular enzyme responsible for O-linked N-acetylglucosamine (O-GlcNAc) glycosylation, and the deregulation of OGT activity occurs in cancer, diabetes, and neurodegenerative disease. Here we develop a single quantum dot (QD)-based nanosensor for sensitive OGT assay. We design a Cy5/biotin-modified peptide with a serine hydroxyl group for sensing OGT and a protease site adjacent to the glycosylation site for proteinase cleavage, with a universal nonradioactive UDP-GlcNAc as the sugar donor and a Cy5/biotin-modified peptide as the substrate. In the presence of OGT, it catalyzes the glycosylation reaction to generate a glycosylated peptide that is a protease-protection peptide. The resultant glycosylated Cy5/biotin-modified peptides may assemble on the surface of the streptavidin-coated QD to obtain a QD–peptide–Cy5 nanostructure in which the fluorescence resonance energy transfer (FRET) from the QD to Cy5 can occur, leading to the emission of Cy5 which can be quantified by single-molecule detection. This method exhibits high sensitivity with a limit of detection of 3.47 × 10–13 M, and it is very simple and straightforward without the involvement of any enzyme purification, radioisotope-labeled sugar donors, specific antibodies, and the synthesis of fluorescent UDP-GlcNAc analogues. Moreover, this method can be used for enzyme kinetic analysis, quantitative detection of cellular OGT activity, and the screening of OGT inhibitors, holding great potential for further application in drug discovery and clinical diagnosis.
Co-reporter:Yuming Dong, Linggang Kong, Pingping Jiang, Guangli Wang, Na Zhao, Huizhen Zhang, and Bo Tang
ACS Sustainable Chemistry & Engineering August 7, 2017 Volume 5(Issue 8) pp:6845-6845
Publication Date(Web):June 8, 2017
DOI:10.1021/acssuschemeng.7b01079
Presently, precise deposition of transition metal phosphides at the electron outlet of photoactive materials as cocatalysts for hydrogen generation is rarely reported. Demonstrated here is a general photochemical strategy for the preparation of metal phosphides as cocatalysts for hydrogen generation. In this work, NixP was successfully deposited on g-C3N4 using nickel sulfate (NiSO4) and hypophosphite sodium (NaH2PO2) as Ni and P sources, respectively. The NixP/g-C3N4 composite exhibits excellent performance of hydrogen evolution via water splitting (about 8585 μmol g–1 h–1 in a triethanolamine aqueous solution under a 300 W Xe lamp with an AM 1.5G filter). More importantly, due to the intrinsic acid-resistant properties of NixP and g-C3N4, the NixP/g-C3N4 composite demonstrated excellent acid-stable photocatalytic activity for H2 evolution (stable run for 75 h under acidic solution of pH 2). Furthermore, the mechanism for photocatalytic activity of g-C3N4 enhanced by NixP was investigated in detail by steady-state photoluminescence spectra and surface photovoltage spectra, which indicated that separation efficiency of photogenerated carriers from g-C3N4 was effectively enhanced by NixP.Keywords: Hydrogen generation; Metal phosphide; Photocatalysis; Photochemical; Water splitting;
Co-reporter:Limin Yang, Yuanyuan Chen, Zhengze Yu, Wei Pan, Hongyu Wang, Na Li, and Bo Tang
ACS Applied Materials & Interfaces August 23, 2017 Volume 9(Issue 33) pp:27512-27512
Publication Date(Web):August 3, 2017
DOI:10.1021/acsami.7b08223
Autophagy and apoptosis are closely associated with various pathological and physiological processes in cell cycles. Investigating the dynamic changes of intracellular active molecules in autophagy and apoptosis is of great significance for clarifying their inter-relationship and regulating mechanism in many diseases. In this study, we develop a dual-ratiometric fluorescent nanoprobe for quantitatively differentiating the dynamic process of superoxide anion (O2•–) and pH changes in autophagy and apoptosis in HeLa cells. A rhodamine B-loaded mesoporous silica core was used as the reference, and fluorescence probes for pH and O2•– measurement were doped in the outer layer shell of SiO2. Then, chitosan and triphenylphosphonium were modified on the surface of SiO2. The experimental results showed that the nanoprobe is able to simultaneously and precisely visualize the changes of mitochondrial O2•– and pH in HeLa cells. The kinetics data revealed that the changes of pH and O2•– during autophagy and apoptosis in HeLa cells were significantly different. The pH value was decreased at the early stage of apoptosis and autophagy, whereas the O2•– level was enhanced at the early stage of apoptosis and almost unchanged at the initial stage of autophagy. At the late stage of apoptosis and autophagy, the concentration of O2•– was increased, whereas the pH was decreased at the late stage of autophagy and almost unchanged at the late stage of apoptosis. We hope that the present results provide useful information for studying the effects of O2•– and pH in autophagy and apoptosis in various pathological conditions and diseases.Keywords: apoptosis; autophagy; dual-ratiometric; dynamic process; nanoprobe; pH; superoxide anion;
Co-reporter:Yuhui Sun, Wen Gao, Yujie Zhao, Wenhua Cao, Zhenhua Liu, Guanwei Cui, Lili Tong, Fengcai Lei, and Bo Tang
Analytical Chemistry April 18, 2017 Volume 89(Issue 8) pp:4642-4642
Publication Date(Web):March 31, 2017
DOI:10.1021/acs.analchem.7b00221
High concentrations of oxidized low density lipoprotein (oxLDL) induce aberrant apoptosis of vascular smooth muscle cells (VSMCs) in atherosclerotic plaques. This apoptosis cannot be blocked completely by the inhibition of caspase, and it eventually potentiates plaque disruption and risk for cardiovascular disease. Given the important role of apoptosis inducing factor (AIF) in caspase-independent apoptosis, here we develop an AIF-targeting nanosensor by the assembly of graphene oxide (GO) nanosheets and dye-labeled DNA hybrid structures. This nanosensor selectively localizes in the cytosol of VSMCs, where it exhibits a “turn-off” fluorescence signal. Under oxLDL stimuli, the release of AIF from mitochondria into cytosol liberates the DNA hybrid structures from the surface of GO and results in a “turn-on” fluorescence signal. This nanosensor is shown to possess rapid response, high sensitivity, and selectivity for AIF that enables real-time imaging of AIF translocation in VSMCs. Using this novel nanosensor, a better assessment of the apoptotic level of VSMCs and a more accurate evaluation of the extent of atherosclerotic lesions can be obtained. More importantly, the abundant binding between DNA hybrid structures and AIF inhibits the translocation of AIF into the nucleus and subsequent apoptosis in VSMCs. This inhibition may help stabilize plaque and reduce the risk of heart attack and stroke.
Co-reporter:Lu Li, Yuanyuan Fan, Qingling Li, Renjie Sheng, Haibin Si, Juan Fang, Lili Tong, and Bo Tang
Analytical Chemistry April 18, 2017 Volume 89(Issue 8) pp:4559-4559
Publication Date(Web):March 24, 2017
DOI:10.1021/acs.analchem.6b05045
Various intracellular metal ions have closely related functional roles in the nervous system. An excess or deficiency of essential metal ions can contribute to neurodegenerative diseases. Thus, the detection of various metal ions in neurons is important for diagnosing and monitoring these diseases. In particular, single-cell analysis of multiple metal ions allows us to not only understand the cellular heterogeneity and differentiation but also determine the actual relationships among multiple metal ions in each individual cell. Aiming at the low efficient single-cell manipulation and interference of complex biological matrices within cells in the existing method for single-cell metal ion detection, in this manuscript, we present a convenient, sensitive, and reliable method to simultaneously identify and quantify multiple metal ions at the single-cell level using a microfluidic system. Using the combination of on-chip electrophoresis separation and multicolor fluorescence detection, we achieved the simultaneous analysis of Na+, K+, Ca2+, and Mg2+ in single PC-12 cells and studied changes in these four metal ions in Aβ25–35-treated PC-12 cells, which is a model of Alzheimer’s disease (AD). The data showed that metal ions imbalances in neuron-like cells may be associated with AD induced by Aβ25–35. This method paves the way for multiple metal ion detection in single neuron-like cells, and the results provide insights regarding synergistic function of multiple metal ions in regulation of neurological diseases at the single-cell level.
Co-reporter:Pin Hao;Guanwei Cui;Xifeng Shi;Junfeng Xie;Xinyuan Xia;Yuanhua Sang;C. P. Wong;Hong Liu
Chinese Journal of Chemistry 2017 Volume 35(Issue 5) pp:699-706
Publication Date(Web):2017/05/01
DOI:10.1002/cjoc.201600722
Supercapacitor electrodes with porous structure based on renewable, eco-friendly and cost-effective materials have caused extensive concern in energy storage fields. Sliced bread, the common food ingredient, mainly containing glucose polymers, can be a promising candidate to fabricate porous supercapacitor electrodes. Highly porous carbon aerogels by using sliced bread as the raw material were synthesized through a carefully controlled aerogel carbonization-activation process. Interestingly, the specific surface area and the pore size distribution of the porous carbon were controlled by the activation temperature, which result in the varied performance of the carbon aerogel as a supercapacitor. Electrochemical investigation measurements revealed that the hierarchical porous carbon aerogel shows an excellent capacitor behavior for construction of a symmetric supercapacitor, which demonstrated a high specific capacitance of 229 F•g−1 at discharge current of 0.2 A•g−1. In addition, the fabricated supercapacitor displayed excellent capacitance retention of 95.5% over 5000 cycles.
Co-reporter:Mingming Luan;Na Li;Wei Pan;Limin Yang;Zhengze Yu
Chemical Communications 2017 vol. 53(Issue 2) pp:356-359
Publication Date(Web):2016/12/22
DOI:10.1039/C6CC07605J
We develop a multicolor fluorescent nanoprobe for assessing cellular migration and invasion by simultaneously imaging miRNA-221, PTEN mRNA and MMP-9 involved in the PI3K/AKT pathway which can regulate cellular mobility and invasiveness.
Co-reporter:Hongyu Wang;Yanfei Ren;Kaiye Wang;Yunquan Man;Yanan Xiang;Na Li
Chemical Communications 2017 vol. 53(Issue 69) pp:9644-9647
Publication Date(Web):2017/08/24
DOI:10.1039/C7CC04911K
A novel method for concisely synthesizing 1,2,4-triazolines via [3+2] cyclization under visible light is reported. These compounds can be easily converted into 1,2,4-triazoles under basic or photoredox conditions. The application of the 1,2,4-triazoles was also investigated via mild operations.
Co-reporter:Zhenhua Liu;Huimin Ji;Wen Gao;Guangyu Zhu;Lili Tong;Fengcai Lei
Chemical Communications 2017 vol. 53(Issue 46) pp:6259-6262
Publication Date(Web):2017/06/06
DOI:10.1039/C7CC02391J
A copper(I)-mediated carboamination cascade reaction between vinyl azides and aryldiazonium salts is described. Functionally diverse N2-substituted 1,2,3-triazoles were obtained in moderate to good yields through novel difunctionalization of vinyl azides by aryldiazonium salt sources. This method has a wide scope, good functional-group tolerance and insensitivity to an ambient atmosphere.
Co-reporter:Yong Li;Xilei Xie;Xiu’e Yang;Mengmeng Li;Xiaoyun Jiao;Yuhui Sun;Xu Wang
Chemical Science (2010-Present) 2017 vol. 8(Issue 5) pp:4006-4011
Publication Date(Web):2017/05/03
DOI:10.1039/C7SC00303J
Drug-induced injury has attracted increasing attention in public health issues. Among them, hepatotoxicity has been regarded as the leading clinical problem caused by drug toxicity. However, owing to the complexity of the involved pathophysiological mechanisms and the lack of noninvasive, straightforward, and real-time tools, drug-induced hepatotoxicity has rarely been predicted satisfactorily. In this paper, by utilizing the reactive species peroxynitrite (ONOO−) as a biomarker, we present a two-photon fluorescent probe, TP-KA, holding rapid response, high specificity and sensitivity towards ONOO−, to investigate drug (acetaminophen and tolcapone)-related liver injury and the remediate effect of N-acetyl cysteine (NAC). With the support of TP-KA, we obtained direct and visual evidence of the upregulation of ONOO− during drug challenge both in live cells and mice, which was accompanied by liver tissue injury and tyrosine nitration. These findings demonstrate that ONOO− is a good and appropriate biomarker of hepatotoxicity, and nitrosative stress may be necessary for acetaminophen and tolcapone to exert their toxicity. Moreover, TP-KA can be employed as a powerful tool to pre-detect drug-induced organism injury and study the effect of antidotes.
Co-reporter:Haibin Xiao;Chuanchen Wu;Ping Li;Wen Gao;Wen Zhang;Wei Zhang;Lili Tong
Chemical Science (2010-Present) 2017 vol. 8(Issue 10) pp:7025-7030
Publication Date(Web):2017/09/25
DOI:10.1039/C7SC02330H
As one of the complications of diabetes, liver injury results in significant hazards. Therefore, accurately diagnosing diabetes-induced liver injury beforehand is crucial for the warning and treatment of hepatic diseases. Diabetes-induced liver injury can cause changes in the microstructure and morphology of liver tissue, leading to changes in the hydrophilic and hydrophobic domains in the endoplasmic reticulum (ER), which is closely associated with changes in cellular ER polarity. So, differences in the ER polarity can indicate the degree of diabetes-induced liver injury. Herein, we develop a new fluorescent and photoacoustic dual-mode probe, ER-P, for detection of the ER polarity of liver tissue in normal and diabetic mice. Upon excitation with a 633 nm laser, ER-P showed increasing fluorescence intensity at 800 nm accompanying a decline in the polarity. Due to its polarity-sensitivity, ER-P was utilized for confocal fluorescence imaging in live cells, and the results demonstrate that ER-P can exclusively accumulate in the ER and indicate an increase in the polarity during ER stress. Importantly, ER-P displayed different absorbance intensities at 700 nm and 800 nm in different polarity environments because of intramolecular charge transfer. The photoacoustic intensity ratios between 700 nm and 800 nm will enable quantification of polarity to be achieved. The ratiometric photoacoustic imaging data demonstrate that the polarity of the liver tissue of diabetic mice is higher than that of the liver tissue of normal mice. Meanwhile, after treatment with the antidiabetic drug metformin, diabetic mice exhibit a reduced polarity environment in their liver tissue. The proposed study may serve as a new approach for the early diagnosis and therapeutic evaluation of diabetes-induced liver injury.
Co-reporter:Yanhua Li;Yuanyuan Chen;Wei Pan;Zhengze Yu;Limin Yang;Hongyu Wang;Na Li
Nanoscale (2009-Present) 2017 vol. 9(Issue 44) pp:17318-17324
Publication Date(Web):2017/11/16
DOI:10.1039/C7NR06479A
The fabrication of well-behaved drug delivery systems that can transport drugs to specifically treat cancer cells rather than normal cells is still a tremendous challenge. A novel drug delivery system with two types of tumor-related mRNAs as “keys” to open the multiple valves of the nanocarrier to control drug release was developed. Hollow mesoporous silica nanoparticles were employed as the nanocarrier and dual DNAs targeting two intracellular mRNAs were employed as “multi-locks” to lock up the nanocarrier. When the nanocarrier enters the cancer cells, the overexpressed endogenous mRNA keys hybridize with the DNA multi-locks to open the valves and release the drug. Each single mRNA could not trigger the opening of the locks to release the cargo. Therefore, the nanocarrier can be applied for specific chemotherapy against cancer cells with minor side effects to normal cells. The current strategy could provide an important avenue towards advancing the practical applications of drug delivery systems used for cancer therapy.
Co-reporter:Chuanxi Yang;Wenping Dong;Guanwei Cui;Yingqiang Zhao;Xifeng Shi;Xinyuan Xia;Weiliang Wang
RSC Advances (2011-Present) 2017 vol. 7(Issue 38) pp:23699-23708
Publication Date(Web):2017/04/27
DOI:10.1039/C7RA02423A
To enhance the photocatalytic activity of TiO2, poly-2-aminobenzene sulfonic acid (P2ABSA)-modified TiO2 nanocomposites were successfully synthesized using an in situ oxidative polymerization method. The modified nanocomposites were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, and a photocurrent test. The photocatalytic degradation of methylene blue was chosen as a model reaction to evaluate the photocatalytic activities of TiO2 and P2ABSA/TiO2 nanocomposites, with results indicating that P2ABSA/TiO2 exhibited the higher activity. The apparent first-order rate constant, kapp, of P/T(2/1) was 0.0138 min−1, which was six times higher than that of TiO2 (0.0021 min−1). Meanwhile, the P2ABSA/TiO2 nanocomposites showed excellent photocatalytic stability, which was dependent on structural stability. A photocatalytic activity enhanced mechanism has been proposed, accounting for the photosensitization effect and synergetic effect of TiO2 with P2ABSA. Mass spectroscopy analysis showed that there were two possible degradation pathways for MB, via degradation of the chromophoric group or the auxochrome group.
Co-reporter:Wen Gao, Shuangshuang Li, Zhenhua Liu, Yuhui Sun, Wenhua Cao, Lili Tong, Guanwei Cui, Bo Tang
Biomaterials 2017 Volume 139(Volume 139) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.biomaterials.2017.05.037
Attacking the supportive vasculature network of a tumor offers an important new avenue for cancer therapy. Herein, a near-infrared (NIR) laser-activated “nanobomb” was developed as a noninvasive and targeted physical therapeutic strategy to effectively disrupt tumor neovasculature in an accurate and expeditious manner. This “nanobomb” was rationally fabricated via the encapsulation of vinyl azide (VA) into c(RGDfE) peptide-functionalized, hollow copper sulfide (HCuS) nanoparticles. The resulting RGD@HCuS(VA) was selectively internalized into integrin αvβ3-expressing tumor vasculature endothelial cells and dramatically increased the photoacoustic signals from the tumor neovasculature, achieving a maximum signal-to-noise ratio at 4 h post-injection. Upon NIR irradiation, the local temperature increase triggered VA to release N2 bubbles rapidly. Subsequently, these N2 bubbles could instantly explode to destroy the neovasculature and further induce necrosis of the surrounding tumor cells. A single-dose injection of RGD@HCuS(VA) led to complete tumor regression after laser irradiation, with no tumor regrowth for 30 days. More importantly, high-resolution photoacoustic angiography, combined with excellent biodegradability, facilitated the precise destruction of tumor neovasculature by RGD@HCuS(VA) without damaging normal tissues. These results demonstrate the great potential of this “nanobomb” for clinical translation to treat cancer patients with NIR laser-accessible orthotopic tumors.
Co-reporter:Chuanxi Yang, Wenping Dong, Guanwei Cui, Yingqiang Zhao, Xifeng Shi, Xinyuan Xia, Bo Tang, Weiliang Wang
Electrochimica Acta 2017 Volume 247(Volume 247) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.electacta.2017.07.037
•Photocatalytic activity of PANI/TiO2 depended on the contents of PANI.•The photosensitization and synergetic effect of PANI/TiO2 enhanced the catalytic activity.•Photocatalytic activity showed up-down-up-down trend with different contents of PANI.Polyaniline (PANI) modified TiO2 nanocomposites were successfully synthesized via an ‘in situ’ oxidative polymerization method. The modified nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectra, thermogravimetric analysis, cyclic voltammetry, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic degradation of methylene blue was chosen as a model reaction to evaluate the photocatalytic activities of TiO2 and PANI/TiO2. The results indicated that PANI/TiO2 nanocomposites exhibited good photocatalytic activity (apparent first-order rate constants of 0.0021 min−1 for TiO2 and 0.0051 min−1 for P/T(1/5)) and stability (recycled 5 times, 15 hours of operation). The photocatalytic activity of PANI/TiO2 increased as the initial pH increased because of electrostatic adsorption between the photocatalyst and MB as well as the generation of ·OH, whereas it exhibited an earlier increasing (from 0.5 g/L to 1.0 g/L) and later decreasing (from 1.0 g/L to 2.0 g/L) trend as the concentration of the photocatalyst increased owing to the absorption of visible light. The photocatalytic stability of the PANI/TiO2 nanocomposite was dependent on the stability of its structure. The possible photocatalytic mechanism and photocatalytic activity enhanced mechanism has been proposed, taking into account the photosensitization effect and synergetic effect of TiO2 with PANI.A novel PANI/TiO2 nanocomposite was synthesized via an ‘in situ’ oxidative polymerization method. The photocatalytic activity enhanced mechanism has been proposed, taking into account the photosensitization effect and synergetic effect of TiO2 with PANI.Download high-res image (114KB)Download full-size image
Co-reporter:Zhenzhen Chen;Yaxin Niu;Guiying Cheng;Lili Tong;Guanglu Zhang;Feng Cai;Tingting Chen;Bao Liu
Analyst (1876-Present) 2017 vol. 142(Issue 15) pp:2781-2785
Publication Date(Web):2017/07/24
DOI:10.1039/C7AN00595D
The development of fast, sensitive, selective and flexible methods for the detection of iodide is highly demanded and is of great significance. In this work, single-stranded DNA-templated copper nanoparticles (ssDNA-CuNPs) generated by sodium ascorbate reduction of Cu2+ along the single-stranded DNA of poly-T were utilized as a fluorescent probe for the determination of iodide ions (I−). The detection scheme is based on the instant quenching of the fluorescence of ssDNA-CuNPs by iodide ions. I− can be quantified in the concentration range from 0.050 to 40 μM and from 40 to 80 μM, and the limit of detection is as low as 15 nM. This method provides a simple and convenient strategy for the biochemical assay of I−, which is also helpful for early diagnosis of related diseases. The establishment of a low cost and fast detection method would be particularly important in developing countries where medical supplies are lacking.
Co-reporter:Lin Cui;Mengfei Lu;Xiao-yun Yang;Chun-yang Zhang
Analyst (1876-Present) 2017 vol. 142(Issue 9) pp:1562-1568
Publication Date(Web):2017/05/02
DOI:10.1039/C7AN00342K
A simple ratiometric electrochemical biosensor is developed for sensitive detection of target DNA based on DNA four-way junction (DNA-4WJ) formation and enzyme-assisted recycling amplification. This biosensor can be easily fabricated by a one-step assembly of ratiometric probes and simply performed by a one-step incubation procedure. In the presence of target DNA, two unmodified DNA oligonucleotides may cooperatively hybridize with a hairpin probe in the triple-helix molecular beacon (THMB) to form a DNA-4WJ, which may cause conformational transduction and induce the change in the distance between two redox labeling probes and the electrode surface. The subsequent recognition and cleavage of DNA-4WJ quadripartite complexes by RNase HII may result in significant signal amplification. Due to the introduction of DNA-4WJ formation, enzyme-assisted recycling amplification and ratiometric measurement, this biosensor exhibits high sensitivity with a detection limit as low as 0.063 pM and a long dynamic range from 0.1 pM to 100 nM. Moreover, this biosensor demonstrates good performance with excellent selectivity, high reliability and good reproducibility, holding great potential for further applications in biomedical research and clinical diagnostics.
Co-reporter:Huihui Li;Jin Shen;Rongwei Cui;Chongmei Sun;Yanyan Zhao;Xia Wu;Na Li
Analyst (1876-Present) 2017 vol. 142(Issue 22) pp:4240-4246
Publication Date(Web):2017/11/06
DOI:10.1039/C7AN00961E
Highly selective determination of dopamine (DA) over other catecholamines is an urgent need for the precise diagnosis and therapy of DA related diseases. Herein, a new formate-bridged Tb(III)-complex and silver nanoparticles (AgNPs) enhanced fluorescent nanosensor was constructed. HCOO− acted as a co-ligand of Tb(III) and also as a linker between the Tb(III) complex and AgNPs and more readily combined with the primary amine of DA than with epinephrine (EP). The formate-bridged action strengthened AgNPs-based surface enhanced fluorescence of the Tb3+-DA complex and improved the selectivity towards DA. Under neutral buffer conditions, the detection limit for the assay of DA was down to 0.15 nM (S/N = 3) with a linear range from 0.5 nM to 100 nM (R2 = 0.9978). Furthermore, the nanosensor could successfully distinguish DA from EP.
Co-reporter:Na Li;Yanli Li;Xiaonan Gao;Zhengze Yu;Wei Pan
Chemical Communications 2017 vol. 53(Issue 36) pp:4962-4965
Publication Date(Web):2017/05/02
DOI:10.1039/C7CC00822H
We demonstrate a novel DNAzymes-based nanocomposite that can simultaneously silence three types of genes in living cells and in vivo. The synergetic strategy for silencing three different genes can significantly enhance the knockdown efficacy and effectively inhibit the cancer cells’ progression.
Co-reporter:Jie Shi;Qianchun Deng;Chuyun Wan;Mingming Zheng;Fenghong Huang
Chemical Science (2010-Present) 2017 vol. 8(Issue 9) pp:6188-6195
Publication Date(Web):2017/08/21
DOI:10.1039/C7SC02189E
As a sudden inflammation of the pancreas, acute pancreatitis presents severe complications and a high mortality rate, despite treatment. Lipase in serum serves as an essential biomarker of acute pancreatitis and even pancreatic cancer. Therefore, developing robust, convenient and sensitive probing of lipase levels is greatly needed. In this work, we present glutamate functionalized tetraphenylethylene (TPE) as a “turn-on” fluorescent probe (S1) based on the aggregation-induced emission (AIE) mechanism for lipase levels with new recognition units. In heterogeneous media, the hydrophilic amino and carboxyl groups in the probe were specifically introduced to facilitate its full access to lipase at the oil–water interface and achieve an interfacially controlled AIE process. The linear response of fluorescence ranging from 0 to 80 U L−1, which included the concentration range of the lipase level in human serum, considering the dilution factor if necessary, the limit of detection as low as 0.13 U L−1, and the fast response time (7 min) were determined. The value of the apparent Michaelis–Menten constant (Km) was obtained as 4.23 μM, which indicated superior affinity between lipase and the probe molecule. The selectivity, photostability, dynamic monitoring of the enzymatic reaction, and preliminary commercial enzyme activity screening were summarized. As far as we know, this is the fastest, easiest and most sensitive method for lipase level probing in the reported literature. Finally, probing the lipase level for the first time in real human serum samples was also conducted successfully.
Co-reporter:Zhengze Yu;Meimei Wang;Wei Pan;Hongyu Wang;Na Li
Chemical Science (2010-Present) 2017 vol. 8(Issue 7) pp:4896-4903
Publication Date(Web):2017/06/26
DOI:10.1039/C7SC00700K
Nanoparticles as novel theranostic agents for cancer treatment have been extensively investigated in recent years. However, the poor tumor selectivity and retention of the theranostic agents result in unsatisfactory performance of both the diagnostic and therapeutic functions. Herein, we developed an alpha-cyclodextrin (α-CD)-based gold/DNA nanomachine for tumor-selective diagnosis and therapy. The α-CDs were capped at the ends of DNA, and their release was triggered by the low pH of the tumor microenvironment, which further resulted in DNA self-assembly through complementary base pairing. The large-sized gold aggregates failed to escape from the tumor tissue, thereby realizing the goal of tumor-specific targeting and enhanced retention. Thus, the photoacoustic signal and photothermal effect are also activated, thereby achieving tumor-targeted photoacoustic imaging and photothermal therapy. In vivo results indicated that the designed gold nanomachines can serve as efficient theranostic agents for diagnosis and therapy. Moreover, we found that the α-CD caps have the ability to protect the nanoparticles from clearance and enzyme digestion, which helps the nanoparticles reach the tumor more efficiently.
Co-reporter:Hongyu Wang;Yanfei Ren;Kaiye Wang;Yunquan Man;Yanan Xiang;Na Li
Chemical Communications 2017 vol. 53(Issue 69) pp:9644-9647
Publication Date(Web):2017/08/24
DOI:10.1039/C7CC04911K
A novel method for concisely synthesizing 1,2,4-triazolines via [3+2] cyclization under visible light is reported. These compounds can be easily converted into 1,2,4-triazoles under basic or photoredox conditions. The application of the 1,2,4-triazoles was also investigated via mild operations.
Co-reporter:Yanhua Li, Na Li, Wei Pan, Zhengze Yu, Limin Yang, and Bo Tang
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 3) pp:
Publication Date(Web):December 22, 2016
DOI:10.1021/acsami.6b13876
A size-controllable and facile synthetic strategy has been developed to fabricate a series of hollow mesoporous silica nanoparticles (HMSNs) with tunable hollow cores or shell thicknesses by employing gold nanoparticles (Au NPs) and cetyltrimethylammonium bromide (CTAB) as dual templates. Various sizes of Au NPs and different amounts of tetraethyl orthosilicate contributed to structure-tailored mesoporous silica-coated Au NPs. After calcination, CTAB molecules were completely removed, and Au NPs could still support the silica shell due to the high melting point. HMSNs were ultimately obtained by etching Au NPs. Applications of HMSNs as nanocarriers for delivering drugs were investigated. Significantly, it was flexible and convenient to control drug-loading/releasing behavior of HMSNs just by tuning the hollow cores or shell thicknesses. Intracellular experiments have proven that HMSNs are suitable for delivering drugs. We anticipate that this study could provide an important avenue for the synthesis of HMSNs and further contribute to advancing practical applications of HMSNs in drug delivery systems.Keywords: Au NPs; drug-loading; drug-releasing; hollow cavity; hollow mesoporous silica nanoparticles; shell thickness;
Co-reporter:Xiaojun Liu, Aishan Zheng, Dongrui Luan, Xiaoting Wang, Fanpeng Kong, Lili Tong, Kehua Xu, and Bo Tang
Analytical Chemistry 2017 Volume 89(Issue 3) pp:
Publication Date(Web):January 5, 2017
DOI:10.1021/acs.analchem.6b04094
The discovery that hypobromous acid (HOBr) can regulate the activity of collagen IV has attracted great attention. However, HOBr as an important reactive small molecule has hardly ever been studied using a detection method suitable for organisms. Herein, a high-quantum-yield mitochondria-targeting near-infrared (NIR) fluorescent probe for HOBr, RhSN-mito, was designed. RhSN-mito was easily obtained by the Suzuki cross-coupling reaction. The test results show that RhSN-mito can rapidly respond to HOBr with ultrasensitivity and high selectivity. The achievement of ultrasensitivity lies in the high signal-to-noise ratio and the highest fluorescence quantum yield of the reaction product (ΦF = 0.68) in the near-infrared region, as far as we know. RhSN-mito is successfully applied to image native HOBr in mitochondria of HepG2 cells and zebrafish. Thus, RhSN-mito is a powerful tool for detecting native HOBr in vivo and is expected to provide a method to further study the physiological and pathological functions related to HOBr.
Co-reporter:Xilei Xie, Mengmeng Li, Fuyan Tang, Yong Li, Leilei Zhang, Xiaoyun Jiao, Xu Wang, and Bo Tang
Analytical Chemistry 2017 Volume 89(Issue 5) pp:
Publication Date(Web):February 7, 2017
DOI:10.1021/acs.analchem.6b04608
We present a feasible paradigm of developing original fluorescent probes for target biomolecules via combinatorial chemistry. In this developmental program, pyrimidine moieties were investigated and optimized as unique recognition units for thiols for the first time through a parallel synthesis in combination with a rapid screening process. This time-efficient and cost-saving process effectively facilitated the developmental progress and provided detailed structure–reactivity relationships. As a result, Res-Biot and Flu-Pht were identified as optimal fluorescent probes for biothiol and thiophenol, respectively. Their favorable characteristics and superior applicability have been well demonstrated in both chemical and biological contexts. In particular, Res-Biot enables the direct visualization of biothiol fluctuations during oxidative stress and cell apoptosis, indicating its suitability in elucidation of a specific pathophysiological process in both living cells and living animals. Meanwhile, Flu-Pht is competent to visualize thiophenols without the interference from endogenous biothiols in living cells.
Co-reporter:Li-Juan Wang;Zi-Yue Wang;Qianyi Zhang;Chun-Yang Zhang
Chemical Communications 2017 vol. 53(Issue 27) pp:3878-3881
Publication Date(Web):2017/03/30
DOI:10.1039/C7CC00946A
We develop a new fluorescence method for real-time monitoring of thymine DNA glycosylase (TDG) activity through cyclic enzymatic repairing-mediated dual-signal amplification. This method exhibits excellent sensitivity with a detection limit of 5.6 × 10−7 U μL−1, and it can be used to determine kinetic parameters and quantify TDG activity from even single cancer cells.
Co-reporter:Ji-Sen Li;Jing-Quan Sha;Bing Du
Chemical Communications 2017 vol. 53(Issue 93) pp:12576-12579
Publication Date(Web):2017/11/21
DOI:10.1039/C7CC06660K
A coupled hybrid of molybdenum phosphide (MoP) and reduced graphene oxide has been prepared for the first time utilizing Mo-MOFs as precursors through a facile method. The nanocomposite exhibits superior electrocatalytic performance towards the HER, and is one of the best high-performance MoP-based electrocatalysts under acidic conditions reported so far.
Co-reporter:Li-Juan Wang;Ming-Li Luo;Qianyi Zhang;Chun-Yang Zhang
Chemical Communications 2017 vol. 53(Issue 80) pp:11016-11019
Publication Date(Web):2017/10/05
DOI:10.1039/C7CC05485H
We developed a simple and rapid method for terminal deoxynucleotidyl transferase (TdT) assay on the basis of the polymerization-directed exonuclease-assisted construction of a single quantum dot (QD)-based fluorescence resonance energy transfer (FRET) nanosensor. This method is very sensitive with a detection limit as low as 1 × 10−6 U μL−1, and it can be used for the screening of TDT inhibitors and accurate quantification of TdT activity even in 5 cancer cells.
Co-reporter:Na Li;Huijun Yang;Zhengze Yu;Yanli Li;Wei Pan;Hongyu Wang
Chemical Science (2010-Present) 2017 vol. 8(Issue 4) pp:2816-2822
Publication Date(Web):2017/03/28
DOI:10.1039/C6SC04293G
Developing effective nonviral siRNA delivery systems for long-term gene silencing remains a great challenge. Here we present a nuclear-targeted siRNA delivery system that can induce long-term gene silencing in cancer cells. The nanocarrier consists of gold nanoparticles modified with a dense shell of synthetic siRNAs and nuclear localization signal (NLS) peptides. The NLS peptide could translocate the nanocarrier into the nucleus and the siRNA was designed to target the promoter of thymidine kinase 1 and trigger the RNA-directed DNA methylation, thereby enabling the nuclear-targeted gene silencing. Compared with traditional gene silencing in cytoplasm, long-lasting gene knockdown could be achieved for the nuclear-targeted nanocarrier, which lasts for more than 30 days. The long-term gene silencing induced by nuclear-targeted siRNA delivery could effectively inhibit the proliferation of cancer cells and prevent the formation of a tumor in a mouse model.
Co-reporter:Xilei Xie;Jilin Fan;Muwen Liang;Yong Li;Xiaoyun Jiao;Xu Wang
Chemical Communications 2017 vol. 53(Issue 87) pp:11941-11944
Publication Date(Web):2017/10/31
DOI:10.1039/C7CC06820D
We report for the first time the development of a two-photon excitable NO photoreleaser, CNNO, for ratiometric imaging and tracking of NO release in live cells. CNNO exhibits the merits of spatiotemporal control in both the site-specific NO release in the selected cell culture region and the controllable vasodilation of mouse aorta ex vivo.
Co-reporter:Yan Zhang;Yueying Li;Chun-yang Zhang
Chemical Communications 2017 vol. 53(Issue 52) pp:6989-6998
Publication Date(Web):2017/06/27
DOI:10.1039/C7CC00901A
SUMOylation is a post-translational modification that plays critical roles in a multitude of cellular processes including transcription, cellular localization, DNA repair and cell cycle progression. Similar to ubiquitin, the small ubiquitin-like modifiers (SUMOs) are covalently attached to the epsilon amino group of lysine residues in the substrates. To understand the regulation and the dynamics of post-translational modifications (PTMs), the identification and quantification of SUMOylation is strictly needed. Although numerous proteomic approaches have been developed to identify hundreds of SUMO target proteins, the number of SUMOylation signatures identified from endogenous modified proteins is limited, and the identification of precise acceptor sites remains a challenge due to the low abundance of in vivo SUMO-modified proteins and the high activity of SUMO-specific proteases in cell lysates. In particular, very few sensitive strategies are available for accurate quantification of SUMO target proteins. Within the past decade, mass spectrometry-based strategies have been the most popular technologies for proteome-wide studies of SUMOylation. Recently, some new approaches such as single-molecule detection have been introduced. In this review, we summarize the strategies that have been exploited for enrichment, purification and identification of SUMOylation substrates and acceptor sites as well as ultrasensitive quantification of SUMOylation. We highlight the emerging trends in this field as well.
Co-reporter:Fei Ma;Wen-jing Liu;Chun-yang Zhang
Chemical Communications 2017 vol. 53(Issue 51) pp:6868-6871
Publication Date(Web):2017/06/22
DOI:10.1039/C7CC03736H
We develop a single quantum dot (QD)-based nanosensor for the signal-on detection of DNA methyltransferase (MTase). By integration of single-molecule counting with the QD-based fluorescence resonance energy transfer (FRET), the proposed nanosensor can sensitively detect DNA MTase with a detection limit of as low as 0.002 U mL−1, and it can be further applied for inhibitor screening and accurate detection of DNA MTase in complex biological samples.
Co-reporter:Ran Wang;Gang Li;Andong Zhang;Wen Wang;Guanwei Cui;Jianfeng Zhao;Zhiqiang Shi
Chemical Communications 2017 vol. 53(Issue 51) pp:6918-6921
Publication Date(Web):2017/06/22
DOI:10.1039/C7CC03682E
We design and synthesize four pyran-embedded perylene diimide (PDI) compounds through a straightforward methodology. UV-driven photocatalytic water splitting using the compounds as photocatalysts demonstrates that the highest photocatalytic H2 evolution rate under UV light is 0.90 mmol g−1 h−1, which paves the way towards organic photoresponsive materials.
Co-reporter:Xilei Xie;Fuyan Tang;Xiaoyan Shangguan;Shiyi Che;Jinye Niu;Yongsheng Xiao;Xu Wang
Chemical Communications 2017 vol. 53(Issue 48) pp:6520-6523
Publication Date(Web):2017/06/13
DOI:10.1039/C7CC03050A
Lyso-TPFP presents lysosomal targetability and an acidic pH-activatable response toward formaldehyde. Thus, it exclusively visualizes lysosomal formaldehyde and is immune against it in neutral cytosol and other organelles. In addition, two-photon fluorescence imaging endows Lyso-TPFP with the capability of in situ tracking formaldehyde in live cells and animals.
Co-reporter:Li-juan Wang;Fei Ma;Chun-yang Zhang
Chemical Science (2010-Present) 2017 vol. 8(Issue 4) pp:2495-2502
Publication Date(Web):2017/03/28
DOI:10.1039/C6SC04801C
Telomerase is a ribonucleoprotein reverse transcriptase that is responsible for maintaining the telomere length in cells. Telomerase overexpresses in almost all malignant tumor cells, and it has become a promising biomarker and a potential therapy target for cancers. Consequently, accurate and efficient quantification of the telomerase is highly essential to medical diagnostics and therapeutics. Recently, a series of novel telomerase detection methods with excellent performance have been developed, but a overview of in vivo telomerase detection methods is lacking. In this Minireview, we summarize the emerging strategies for telomerase assays in the last five years, including both in vitro assays and in vivo imaging methods, and discuss their future directions as well.
Co-reporter:Hongyu Wang;Kaiye Wang;Yanfei Ren;Na Li;Gang Zhao
Advanced Synthesis & Catalysis 2017 Volume 359(Issue 11) pp:1819-1824
Publication Date(Web):2017/06/06
DOI:10.1002/adsc.201700029
AbstractThe application of asymmetric phase-transfer catalysis to the Strecker reaction of ketimines was realized utilizing bifunctional thiourea-phosphonium salts. The asymmetric Strecker reaction of aldimines was also realized utilizing quaternary ammonium salts derived from amino acids.
Co-reporter:Dr. Yu Ma;Xiangyuan Li;Aijie Li;Dr. Peng Yang;Caiyun Zhang; Bo Tang
Angewandte Chemie 2017 Volume 129(Issue 44) pp:13940-13944
Publication Date(Web):2017/10/23
DOI:10.1002/ange.201708005
AbstractPhotodynamic therapy (PDT) has emerged as an important minimally invasive tumor treatment technology. The search for an effective photosensitizer to realize selective cancer treatment has become one of the major foci in recent developments of PDT technology. Controllable singlet-oxygen release based on specific cancer-associated events, as another major layer of selectivity mode, has attracted great attention in recent years. Here, for the first time, we demonstrated that a novel mixed-metal metal–organic framework nanoparticle (MOF NP) photosensitizer can be activated by a hydrogen sulfide (H2S) signaling molecule in a specific tumor microenvironment for PDT against cancer with controllable singlet-oxygen release in living cells. The effective removal of tumors in vivo further confirmed the satisfactory treatment effect of the MOF NP photosensitizer.
Co-reporter:Dr. Peng Yang;Caili Zhang;Dr. Yu Ma;Caiyun Zhang;Aijie Li; Dr. Bo Tang; Dr. Jianrong Steve Zhou
Angewandte Chemie International Edition 2017 Volume 56(Issue 46) pp:14702-14706
Publication Date(Web):2017/11/13
DOI:10.1002/anie.201708949
AbstractA borrowing-hydrogen reaction between amines and alcohols is an atom-economic way to prepare alkylamines, ideally with water as the sole byproduct. Herein, nickel catalysts are used for direct N-alkylation of hydrazides and arylamines using racemic alcohols. Moreover, a nickel catalyst of (S)-binapine was used for an asymmetric N-alkylation of benzohydrazide with racemic benzylic alcohols.
Co-reporter:Fanpeng Kong, Yuehui Zhao, Ziye Liang, Xiaojun Liu, Xiaohong Pan, Dongrui Luan, Kehua Xu, and Bo Tang
Analytical Chemistry 2017 Volume 89(Issue 1) pp:
Publication Date(Web):December 5, 2016
DOI:10.1021/acs.analchem.6b03136
Hydrogen selenide (H2Se) is an important metabolite of dietary Se compounds and has been implicated in various pathological and physiological processes. The development of highly sensitive and selective methods for the sensing of H2Se is therefore very important. Herein, we developed a fluorescent probe (hemicyanine (Hcy)-H2Se) for detecting H2Se based on a new H2Se-specific receptor unit, 1,2-dithiane-4,5-diol. Hcy-H2Se showed high selectivity toward H2Se over thiols (RSH), hydrogen sulfide (H2S), and selenocysteine (Sec) and was further exploited for the fluorescence imaging of H2Se both in living cells and in vivo. Furthermore, with the aid of Hcy-H2Se, we demonstrated that H2Se can be generated and gradually accumulated in HepG2 cells under hypoxic conditions and in the solid tumor after treatment with Na2SeO3.
Co-reporter:Fei Ma, Ying Li, Bo Tang, and Chun-yang Zhang
Accounts of Chemical Research 2016 Volume 49(Issue 9) pp:1722
Publication Date(Web):September 1, 2016
DOI:10.1021/acs.accounts.6b00237
Biosensors for highly sensitive, selective, and rapid quantification of specific biomolecules make great contributions to biomedical research, especially molecular diagnostics. However, conventional methods for biomolecular assays often suffer from insufficient sensitivity and poor specificity. In some case (e.g., early disease diagnostics), the concentration of target biomolecules is too low to be detected by these routine approaches, and cumbersome procedures are needed to improve the detection sensitivity. Therefore, there is an urgent need for rapid and ultrasensitive analytical tools. In this respect, single-molecule fluorescence approaches may well satisfy the requirement and hold promising potential for the development of ultrasensitive biosensors.Encouragingly, owing to the advances in single-molecule microscopy and spectroscopy over past decades, the detection of single fluorescent molecule comes true, greatly boosting the development of highly sensitive biosensors. By in vitro/in vivo labeling of target biomolecules with proper fluorescent tags, the quantification of certain biomolecule at the single-molecule level is achieved. In comparison with conventional ensemble measurements, single-molecule detection-based analytical methods possess the advantages of ultrahigh sensitivity, good selectivity, rapid analysis time, and low sample consumption. Consequently, single-molecule detection may be potentially employed as an ideal analytical approach to quantify low-abundant biomolecules with rapidity and simplicity.In this Account, we will summarize our efforts for developing a series of ultrasensitive biosensors based on single-molecule counting. Single-molecule counting is a member of single-molecule detection technologies and may be used as a very simple and ultrasensitive method to quantify target molecules by simply counting the individual fluorescent bursts. In the fluorescent sensors, the signals of target biomolecules may be translated to the fluorescence signals by specific in vitro/in vivo fluorescent labeling, and consequently, the fluorescent molecules indicate the presence of target molecules. The resultant fluorescence signals may be simply counted by either microfluidic device-integrated confocal microscopy or total internal reflection fluorescence-based single-molecule imaging. We have developed a series of single-molecule counting-based biosensors which can be classified as separation-free and separation-assisted assays. As a proof-of-concept, we demonstrate the applications of single-molecule counting-based biosensors for sensitive detection of various target biomolecules such as DNAs, miRNAs, proteins, enzymes, and intact cells, which may function as the disease-related biomarkers. Moreover, we give a summary of future directions to expand the usability of single-molecule counting-based biosensors including (1) the development of more user-friendly and automated instruments, (2) the discovery of new fluorescent labels and labeling strategies, and (3) the introduction of new concepts for the design of novel biosensors. Due to their high sensitivity, good selectivity, rapidity, and simplicity, we believe that the single-molecule counting-based fluorescent biosensors will indubitably find wide applications in biological research, clinical diagnostics, and drug discovery.
Co-reporter:Ping Li; Lu Liu; Haibin Xiao; Wei Zhang; Lulin Wang
Journal of the American Chemical Society 2016 Volume 138(Issue 9) pp:2893-2896
Publication Date(Web):February 24, 2016
DOI:10.1021/jacs.5b11784
Despite significant developments in optical imaging of superoxide anion (O2•–) as the preliminary reactive oxygen species, novel visualizing strategies that offer ultrahigh sensitivity are still imperative. This is mainly because intrinsic concentrations of O2•– are extremely low in living systems. Herein, we present the rational design and construction of a new polymer nanoprobe PCLA-O2•– for detecting O2•– based on chemiluminescence (CL) resonance energy transfer without an external excitation source. Structurally, PCLA-O2•– contains two moieties linked covalently, namely imidazopyrazinone that is capable of CL triggered by O2•– as the energy donor and conjugated polymers with light-amplifying property as the energy acceptor. Experiment results demonstrate that PCLA-O2•– exhibits ultrahigh sensitivity at the picomole level, dramatically prolonged luminescence time, specificity, and excellent biocompatibility. Without exogenous stimulation, this probe for the first time in situ visualizes O2•– level differences between normal and tumor tissues of mice. These exceptional features ensure that PCLA-O2•– as a self-luminescing probe is an alternative in vivo imaging approach for ultralow level O2•–.
Co-reporter:Haibin Xiao, Ping Li, Wei Zhang and Bo Tang
Chemical Science 2016 vol. 7(Issue 2) pp:1588-1593
Publication Date(Web):23 Nov 2015
DOI:10.1039/C5SC04099J
Mitochondrial polarity is a crucial characteristic of these indispensable organelles, and tremendously impacts cellular events. Herein, we describe a new mitochondria-targeting fluorescent probe MCY-BF2 that is singularly sensitive and specifically responsive to mitochondrial polarity. The pull–push system in the conjugated structure of MCY-BF2 is responsible for the polarity-ultrasensitivity due to the excited state intramolecular charge transfer (ICT). By combining with cardiolipin, MCY-BF2 preferentially accumulates in mitochondria. Because the fluorescence emission wavelengths exhibit an obvious red-shift with increasing media polarity, the fluorescence intensity ratio at two different wavelengths versus the solvent dielectric constant can quantify the mitochondrial polarity. Experimental results demonstrate that the fluorescent intensity of MCY-BF2 in a non-polar solvent, dioxane, is 120 times higher than that in a polar solvent, dimethyl sulfoxide. As the first near-infrared (NIR) and most sensitive fluorescent imaging probe for polarity, MCY-BF2 can locate exclusively in mitochondria in various cells and discriminate polarity differences between normal and cancer cells. Also, the intrinsic polarity variance at different developmental stages in Caenorhabditis elegans (C. elegans) was reported here for the first time. Interestingly, the embryonic development stage has a more non-polar environment with a dielectric constant of 7.20, and in contrast the polarity at the young adult stage changes to 10.07. In addition, in vivo imaging results suggest that the tumor tissues of mice have an obviously lower polarity than that in normal tissues. Altogether, the merits of the NIR property, high sensitivity and moderate Stokes shift all greatly promote the accuracy of imaging. This probe will be a promising tool for studying biological processes and the pathological mechanism of polarity-related diseases.
Co-reporter:Zhengze Yu, Wei Pan, Na Li and Bo Tang
Chemical Science 2016 vol. 7(Issue 7) pp:4237-4244
Publication Date(Web):11 Mar 2016
DOI:10.1039/C6SC00737F
Photodynamic therapy against cancer, especially multidrug resistant cancer, is limited seriously due to the efflux of photosensitizer molecules by P-glycoprotein, which leads to insufficient production of reactive oxygen species (ROS). For the purpose of abundant ROS generation and effective therapeutic response, herein, we firstly design and fabricate a nuclear targeted dual-photosensitizer for photodynamic therapy against multidrug resistant cancer. Molecule-photosensitizer Ce6 was selected and modified on the surface of core/shell structure nano-photosensitizer upconversion@TiO2 and then nuclear targeted peptides TAT were anchored for nuclear targeting. Through selective doping of rare earth elements Er and Tm, multiple ROS (˙OH, O2˙−, and 1O2) can be generated for the dual-photosensitizer and realize their functions synergistically using a single 980 nm NIR excitation. The nano-sized photosensitizer accompanied with nuclear targeting can effectively generate multiple ROS in the nucleus regardless of P-glycoprotein and directly break DNA double strands, which is considered as the most direct and serious lesion type for cytotoxic effects. Therefore, enhanced photodynamic therapy can be achieved against multidrug resistant cancer. In vitro and in vivo studies confirmed the excellent therapeutic effect of the dual-photosensitizer against cancer cells and drug-resistant cancer cells, as well as xenograft tumor models.
Co-reporter:Haibin Xiao, Ping Li, Xiufen Hu, Xiaohui Shi, Wen Zhang and Bo Tang
Chemical Science 2016 vol. 7(Issue 9) pp:6153-6159
Publication Date(Web):01 Jun 2016
DOI:10.1039/C6SC01793B
Cell apoptosis is a biochemical and molecular pathway essential for maintaining cellular homeostasis. It is an integrated process involving in a series of signal transduction cascades. Moreover, the apoptotic pathways may be initiated inside various subcellular organelles. Increasing evidence indicates that hydrogen peroxide (H2O2) is closely related to cell apoptosis, particularly in the mitochondria. However, during the apoptotic process, the synergetic variation of H2O2 levels in different compartments is seldom explored, particularly in two important organelles: mitochondria and endoplasmic reticulum (ER). To solve this problem, we developed two new organelle-specific fluorescent probes termed MI-H2O2 and ER-H2O2 that can detect H2O2 in mitochondria and ER, respectively or simultaneously. Experimental results demonstrated that MI-H2O2 and ER-H2O2 display distinguishable excitation and emission spectra, as well as excellent organelle targeting capabilities. Therefore, we used MI-H2O2 and ER-H2O2 to successfully image exogenous or endogenous hydrogen peroxide in the mitochondria and ER. Interestingly, during diverse apoptotic stimuli, dual-color fluorescence imaging results revealed that the changes of H2O2 levels in mitochondria and ER are different. The H2O2 levels are enhanced in both the mitochondria and ER during the L-buthionine sulfoximine (BSO)-treated cell apoptosis process. During mitochondria-oriented apoptosis induced by carbonyl cyanide m-chlorophenylhydrazone (CCCP) or rotenone, H2O2 levels prominently and continuously increase in the mitochondria, whereas the ER H2O2 levels were found to rise subsequently after a delay. Moreover, during ER-oriented apoptosis induced by tunicamycin, ER is the major site for overproduction of H2O2, and delayed elevation of the H2O2 levels was found in the mitochondria. Altogether, this dual-probe and multicolor imaging approach may offer a proven methodology for studying molecular communication events on H2O2-related apoptosis and also other physiological and pathological processes within different subcellular organelles.
Co-reporter:Lu Li, Jie Feng, Haiyun Liu, Qingling Li, Lili Tong and Bo Tang
Chemical Science 2016 vol. 7(Issue 3) pp:1940-1945
Publication Date(Web):07 Dec 2015
DOI:10.1039/C5SC03909F
In situ imaging of miRNA in living cells could facilitate the monitoring of the dynamic expression and distribution of miRNA and research on miRNA-related cellular processes and diseases. Given the low expression levels and even down-regulation of cellular miRNA that is associated with some diseases, amplification strategies are imperative for intracellular miRNA imaging. The present paper proposes a non-destructive amplification strategy for use in living cells. This amplification strategy utilizes the enzyme-free hybridization chain reaction (HCR) with graphene oxide (GO) as a carrier to image cellular miRNA. The resulting signal amplification provides excellent recognition and signal enhancement of specific miRNAs in living cells. As the fluorescence quencher and probe carrier, GO enables activation of the signal switch and effective intracellular delivery of amplification reagents. This new imaging method realizes simple, sensitive and non-destructive signal amplification of miRNA in living cells and has an ability to simultaneously image two types of miRNA in the same cell. This method supplies accurate information regarding cellular miRNA-related biological events and provides a new tool for highly sensitive and simultaneous imaging of multiple low-level biomarkers, thereby improving the accuracy of early disease diagnosis.
Co-reporter:Fanpeng Kong, Lihong Ge, Xiaohong Pan, Kehua Xu, Xiaojun Liu and Bo Tang
Chemical Science 2016 vol. 7(Issue 2) pp:1051-1056
Publication Date(Web):28 Oct 2015
DOI:10.1039/C5SC03471J
Hydrogen selenide (H2Se), a highly reactive Se species, is an important selenium metabolism intermediate involved in many physiological and pathological processes. This compound is of scientific interest with regard to the real-time monitoring of H2Se in living cells and in vivo to understand the anti-cancer mechanism of selenium. However, monitoring H2Se in living cells is still challenging due to the lack of straight forward, highly selective and rapid methods. Here, we developed a novel small-molecule fluorescent probe, NIR-H2Se, for imaging endogenous H2Se. NIR-H2Se exhibited high selectivity toward H2Se over selenocysteine (Sec), H2S and small molecule thiols and was successfully used to image the H2Se content in HepG2 cells during Na2SeO3-induced apoptosis. Increased H2Se content and reduced ROS levels were observed under hypoxic conditions compared to normoxic conditions, which indicated that the cell apoptosis induced by Na2SeO3 under a hypoxic environment is via a non-oxidative stress mechanism. Thus, this probe should serve as a powerful tool for exploring the physiological function of H2Se and Se anticancer mechanisms in a variety of physiological and pathological contexts.
Co-reporter:Yan Zhang, Fei Ma, Bo Tang and Chun-yang Zhang
Chemical Communications 2016 vol. 52(Issue 26) pp:4739-4748
Publication Date(Web):18 Feb 2016
DOI:10.1039/C5CC09891B
Transcription factors (TFs) play central roles in the regulation of gene expression through binding to specific DNA sequences, and may influence multiple transcription-associated cellular processes including cell development, differentiation, and growth. Alterations in TF levels may lead to a variety of human diseases. Consequently, rapid and sensitive detection of TFs is crucial to both biological research and clinical diagnostics. However, conventional methods for TF assays are usually laborious and time-consuming with poor sensitivity, and sometimes involve the radioactive materials. To overcome these limitations, some new approaches have been developed with a low detection limit, high specificity, high throughput, and low cost. In this paper, we review the recent advances in TF assays and highlight the emerging trends as well.
Co-reporter:Xiaojun Liu, Bo Hu, Ranran Cheng, Fanpeng Kong, Xiaohong Pan, Kehua Xu and Bo Tang
Chemical Communications 2016 vol. 52(Issue 40) pp:6693-6696
Publication Date(Web):19 Apr 2016
DOI:10.1039/C6CC02111E
Based on the rapid substitution reaction of the Au–S bond by selenol, we designed and synthesized a nanoprobe 5-FAM-peptide-AuNPs for selenol. Real-time imaging shows that this probe together with the molecular probe QCy7-H2O2 is able to simultaneously and differentially monitor the concentrations of selenol and H2O2 in living cells and in vivo.
Co-reporter:Wen Gao, Xueping Wei, Xuejun Wang, Guanwei Cui, Zhenhua Liu and Bo Tang
Chemical Communications 2016 vol. 52(Issue 18) pp:3643-3646
Publication Date(Web):05 Feb 2016
DOI:10.1039/C6CC00112B
A competitive coordination-based hydrogen peroxide (H2O2) nanosensor is constructed by the assembly of FAM-tagged single-strand (ss) DNA on cerium oxide nanowires (CeO2 NWs). This fluorescent nanosensor is capable of rapidly and selectively tracking H2O2 within living cells, as well as directly visualizing H2O2 generated by wound-induced oxidative damage in zebrafish larvae.
Co-reporter:Hongyan Zhang, Zhen Zhang, Yanhong Wang, Chuanchen Wu, Qingling Li, and Bo Tang
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 44) pp:29933
Publication Date(Web):October 14, 2016
DOI:10.1021/acsami.6b09490
A strategy based on an immune-graphene oxide (GO)-magnetic microbead complex for the sensitive, rapid, portable, and low-cost detection of cancer cells was developed. The high-efficiency cell capture and high sensitive thermal contrast detection could be simultaneously achieved using magnetic microbeads and the photothermal effect of GOs. The temperature variation caused by irradiating the GOs with a laser was used to establish the standard curve of temperature variation and cancer cell number. Under optimal conditions, the limit of detection could reach 100 cells. 4T1 cells spiked in human blood could be successfully detected in 1.5 h, and the recovery was between 90.8% and 116.5%.Keywords: cancer cell; graphene oxide; magnetic microbead; membrane; photothermal effect
Co-reporter:Wei Pan, Yanli Li, Meimei Wang, Huijun Yang, Na Li and Bo Tang
Chemical Communications 2016 vol. 52(Issue 24) pp:4569-4572
Publication Date(Web):01 Mar 2016
DOI:10.1039/C5CC10147F
We demonstrate a novel strategy using FRET-based nanoprobes for the simultaneous detection of multiple mRNAs with single wavelength excitation in living cells.
Co-reporter:Xuan Kuang, Sujuan Ye, Xiangyuan Li, Yu Ma, Caiyun Zhang and Bo Tang
Chemical Communications 2016 vol. 52(Issue 31) pp:5432-5435
Publication Date(Web):24 Mar 2016
DOI:10.1039/C6CC00320F
For the first time, we report the synthesis of Ag nanoparticles (NPs) arranged in a helical structure on a chiral metal–organic framework via a facile process at room temperature. This material can serve as a new type of surface-enhanced Raman scattering sensor for the efficient recognition of D/L-cysteine and D/L-asparagine enantiomers.
Co-reporter:Lu Li, Qingling Li, Peilin Chen, Zhongyi Li, Zhenzhen Chen, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 1) pp:930
Publication Date(Web):December 7, 2015
DOI:10.1021/acs.analchem.5b03664
As important reactive oxygen species (ROS) and reactive nitrogen species (RNS), cellular superoxide anion (O2•–) and nitric oxide (NO) play significant roles in numerous physiological and pathological processes. Cellular O2•– and NO also have a close relationship and always interact with each other. Thus, the simultaneous detection of intracellular O2•– and NO, especially at the single-cell level, is important. In this paper, we present a novel method to simultaneously detect and quantify O2•– and NO in single cells using microchip electrophoresis based on a new consecutive gated injection method. This novel injection method achieved consecutive manipulation of single cells, guaranteeing an almost constant volumetric flow rate and thus good quantitative reproducibility. After cellular content separation by microchip electrophoresis and detection by laser-induced fluorescence (MCE–LIF), O2•– and NO in single PC-12 cells were simultaneously quantified in an automated fashion. This is the first report of consecutive absolute quantitation at the single-cell level. The quantitative results obtained from single cells is beneficial for deep understanding of the biological roles of cellular O2•– and NO. This new method constitutes a consecutive, accurate way to study the synergistic function of O2•– and NO and other biomolecules in various biological events at the single-cell level.
Co-reporter:Qinfeng Xu, Si-qiang Huang, Fei Ma, Bo Tang, and Chun-yang Zhang
Analytical Chemistry 2016 Volume 88(Issue 4) pp:2431
Publication Date(Web):January 12, 2016
DOI:10.1021/acs.analchem.5b04540
Single-nucleotide polymorphisms (SNPs) are closely related to human diseases and individual drug responses, and the accurate detection of SNPs is crucial to both clinical diagnosis and development of personalized medicine. Among various SNPs detection methods, ligase detection reaction (LDR) has shown great potential due to its low detection limit and excellent specificity. However, frequent involvement of expensive labels increases the experimental cost and compromises the assay efficiency, and the requirement of careful predesigned probes limits it to only known SNPs assays. In this research, we develop a controllable mismatched ligation for bioluminescence screening of both known and unknown mutations. Especially, the ligation specificity of E. coli ligase is tunable under different experimental conditions. The mismatches locating on the 3′-side of the nick cannot be ligated efficiently by E. coli ligase, whereas all mismatches locating on the 5′-side of the nick can be ligated efficiently by E. coli ligase. We design a 3′-discriminating probe (3′-probe) for the discrimination of known mutation and introduce a T7 Endo I for the detection of unknown mutation. With the integration of bioluminescence monitoring of ligation byproduct adenosine 5'-monophosphate (AMP), both known and unknown SNPs can be easily detected without the involvement of any expensive labels and labor-intensive separation. This method is simple, homogeneous, label-free, and cost-effective and may provide a valuable complement to current sequencing technologies for disease diagnostics, personalized medicine, and biomedical research.
Co-reporter:Wei Pan, Honghong Wang, Limin Yang, Zhengze Yu, Na Li, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 13) pp:6743
Publication Date(Web):June 13, 2016
DOI:10.1021/acs.analchem.6b01010
Abnormal pH values in the organelles are closely associated with inappropriate cellular functions and many diseases. Monitoring subcellular pH values and their variations is significant in biological processes occurring in living cells and tissues. Herein, we develop a series of ratiometric fluorescence nanoprobes for quantification and imaging of pH values with a single-wavelength excitation in cytoplasm, lysosomes, and mitochondria. The nanoprobes consist of mesoporous silica nanoparticles assembled with aminofluorescein as the recognition unit for pH measurement and ethidium bromide as reference fluorophore. Further conjugation of subcellular targeting moiety enables the nanoprobes to specifically target lysosome and mitochondria. Confocal fluorescence imaging demonstrated that the nanoprobes could effectively monitor the pH fluctuations from 5.0 to 8.3 in living cells by ratio imaging with 488 nm excitation. Subcellular pH determination and imaging in lysosome and mitochondria could also be achieved in different conditions. The current method can offer a general strategy to determine subcellular analytes and investigate the interactions in biological samples.
Co-reporter:Li-juan Wang, Fei Ma, Bo Tang, and Chun-yang Zhang
Analytical Chemistry 2016 Volume 88(Issue 15) pp:7523
Publication Date(Web):July 12, 2016
DOI:10.1021/acs.analchem.6b00664
DNA glycosylase is an initiating enzyme of cellular base excision repair pathway which is responsible for the repair of various DNA lesions and the maintenance of genomic stability, and the dysregulation of DNA glycosylase activity is associated with a variety of human pathology. Accurate detection of DNA glycosylase activity is critical to both clinical diagnosis and therapeutics, but conventional methods for the DNA glycosylase assay are usually time-consuming with poor sensitivity. Here, we demonstrate the base-excision-repair-induced construction of a single quantum dot (QD)-based sensor for highly sensitive measurement of DNA glycosylase activity. We use human 8-oxoguanine-DNA glycosylase 1 (hOGG1), which is responsible for specifically repairing the damaged 8-hydroxyguanine (8-oxoG, one of the most abundant and widely studied DNA damage products), as a model DNA glycosylase. In the presence of biotin-labeled DNA substrate, the hOGG1 may catalyze the removal of 8-oxo G from 8-oxoG·C base pairs to generate an apurinic/apyrimidinic (AP) site. With the assistance of apurinic/apyrimidinic endonuclease (APE1), the cleavage of the AP site results in the generation of a single-nucleotide gap. Subsequently, DNA polymerase β incorporates a Cy5-labeled dGTP into the DNA substrate to fill the gap. With the addition of streptavidin-coated QDs, a QD-DNA-Cy5 nanostructure is formed via specific biotin–streptavidin binding, inducing the occurrence of fluorescence resonance energy transfer (FRET) from the QD to Cy5. The resulting Cy5 signal can be simply monitored by total internal reflection fluorescence (TIRF) imaging. The proposed method enables highly sensitive measurement of hOGG1 activity with a detection limit of 1.8 × 10–6 U/μL. Moreover, it can be used to measure the enzyme kinetic parameters and detect the hOGG1 activity in crude cell extracts, offering a powerful tool for biomedical research and clinical diagnosis.
Co-reporter:Xilei Xie, Xiu’e Yang, Tianhong Wu, Yong Li, Mengmeng Li, Qi Tan, Xu Wang, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 16) pp:8019
Publication Date(Web):July 21, 2016
DOI:10.1021/acs.analchem.6b01256
Hydrogen peroxide, an important biomolecule, receives earnest attention because of its physiological and pathological functions. In this Article, we present the rational design, characterization, and biological application of a mitochondria-targetable NIR fluorescent sensor, Mito-NIRHP, for hydrogen peroxide visualization. Mito-NIRHP utilizes a unique reaction switch, α-ketoamide moiety, to turn on a highly specific, sensitive, and rapid fluorescence response toward hydrogen peroxide coupled with the intramolecular charge transfer strategy. Mito-NIRHP is competent to track endogenously produced hydrogen peroxide in both living cells and living animals. In addition, utilizing Mito-NIRHP, overgeneration of hydrogen peroxide during ischemia-reperfusion injury was directly visualized at both cell and organ levels.
Co-reporter:Qingling Li, Peilin Chen, Yuanyuan Fan, Xu Wang, Kehua Xu, Lu Li, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 17) pp:8610
Publication Date(Web):August 8, 2016
DOI:10.1021/acs.analchem.6b01775
Single-cell metabolomics can be used to study cell diversity and how cells respond to environment. There is an urgent need to develop effective detection methods for single-cell metabolomics. Microchip electrophoresis with laser-induced fluorescence detection (MCE-LIFD) is a powerful tool to detect metabolites at the single-cell level. However, the existing one-laser excitation and one-color fluorescence collection in MCE-LIFD is not sufficient for the simultaneous detection of multiple small molecules with wide variations in their fluorescence excitation and emission spectra. In this manuscript, we describe a multicolor fluorescence detection-based microfluidic device (MFD-MD) for single-cell metabolomics research. We selected primary liver cells from acute ethanol-stimulated mice as the model cells and hydrogen peroxide (H2O2), glutathione (GSH), and cysteine (Cys) as representative small-molecule metabolites for single-cell analysis. The microfluidic chip enabled accurate single-cell manipulation and effective electrophoresis separation. The new multicolor fluorescence detection permitted simultaneous analysis of H2O2, GSH, and Cys. Ethanol exposure induced an increase in H2O2 and a decrease in GSH and Cys. Obvious cell heterogeneity was observed. These results provide insights regarding the intracellular oxidative/antioxidative molecular mechanism in response to external stimuli. The MFD-MD provides a new opportunity for simultaneous single-cell analysis of multiple metabolites.
Co-reporter:Fanpeng Kong, Ziye Liang, Dongrui Luan, Xiaojun Liu, Kehua Xu, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 12) pp:6450
Publication Date(Web):May 24, 2016
DOI:10.1021/acs.analchem.6b01135
To reduce the side effects of chemotherapy, nontoxic prodrugs activated by the tumor microenvironment are urgently required for use in cancer treatment. In this work, we developed prodrug 4 for tumor-targeting treatment and imaging of the anticancer drug release in vivo. Taking advantage of the high glutathione (GSH) concentration in cancer cells, the disulfide bond in prodrug 4 was cleaved, resulting in the release of an active anticancer drug and a near-infrared (NIR) fluorescence dye turn-on. Furthermore, contrast to the free anticancer drug, the prodrug exhibited higher cytotoxicity to hepatoma cells than that to normal HL-7702 cells. Thus, prodrug 4 is a promising platform for specific tumor-activatable drug delivery system, because of its favorable features of in situ and in vivo monitoring of the drug release and therapeutic efficacy.
Co-reporter:Yong Li, Xu Wang, Jie Yang, Xilei Xie, Mengmeng Li, Jinye Niu, Lili Tong, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 22) pp:11154
Publication Date(Web):October 17, 2016
DOI:10.1021/acs.analchem.6b03376
Carbon monoxide (CO), a crucial gas message molecule, plays an important role in the regulation of physiological and pathological process. Hypoxia-induced CO is involved in modulating various cellular activities, including signal transduction, proliferation, and apoptosis. However, tracking CO fluctuation in the hypoxic cells is still a challenge due to lack of straightforward, visualized, and noninvasive tools. In this work, based on metal palladium-catalyzed reaction, we present the rational design, synthesis, and biological utility of an azobenzene-cyclopalladium-based fluorescent probe, ACP-2, for CO monitoring. ACP-2 exhibits capacity of detecting CO in aqueous buffer solution and live cells with high sensitivity and specificity. Utilizing ACP-2, we displayed a direct and visual evidence of endogenous CO up-regulation in live cells induced by hypoxia. Moreover, CO up-regulation during oxygen-glucose deprivation/reperfusion (OGD/R) was also imaged and certified by ACP-2.
Co-reporter:Qinfeng Xu, Yihong Zhang, Bo Tang, and Chun-yang Zhang
Analytical Chemistry 2016 Volume 88(Issue 4) pp:2051
Publication Date(Web):January 13, 2016
DOI:10.1021/acs.analchem.5b03109
Nanomaterial-based differential sensors (e.g., chemical nose) have shown great potential for identification of multiple proteins because of their modulatable recognition and transduction capability but with the limitation of array separation, single-channel read-out, and long incubation time. Here, we develop a multicolor quantum dot (QD)-based multichannel sensing platform for rapid identification of multiple proteins in an array-free format within 1 min. A protein-binding dye of bromophenol blue (BPB) is explored as an efficient reversible quencher of QDs, and the mixture of BPB with multicolor QDs may generate the quenched QD-BPB complexes. The addition of proteins will disrupt the QD-BPB complexes as a result of the competitive protein-BPB binding, inducing the separation of BPB from the QDs and the generation of distinct fluorescence patterns. The multicolor patterns may be collected at a single-wavelength excitation and differentiated by a linear discriminant analysis (LDA). This multichannel sensing platform allows for the discrimination of ten proteins and seven cell lines with the fastest response rate reported to date, holding great promise for rapid and high-throughput medical diagnostics.
Co-reporter:Bo Hu, Ranran Cheng, Xiaojun Liu, Xiaohong Pan, Fanpeng Kong, Wen Gao, Kehua Xu, Bo Tang
Biomaterials 2016 92() pp: 81-89
Publication Date(Web):1 June 2016
DOI:10.1016/j.biomaterials.2016.03.030
Selenol is a key metabolite of Na2SeO3 and plays an important role in many physiological and pathological processes. The real-time monitoring of selenol is of scientific interest for understanding the anti-cancer mechanism of Na2SeO3. Based on selenol's ability to specifically break AuS bonds and form more stable AuSe bonds on the surfaces of gold nanoparticles (AuNPs), we developed a novel near-infrared fluorescent nanosensor (Cy5.5-peptide-AuNPs) for detecting selenol. The nanosensor exhibited rapid response to selenol with high selectivity and sensitivity, and it was successfully used to image changes in the selenol level in HepG2 cells during Na2SeO3-induced apoptosis. Moreover, in vivo fluorescence imaging of selenol was obtained from H22 tumor-bearing mice injected with both the nanosensor and sodium selenite. The results showed that the tumor cell apoptosis induced by Na2SeO3 is correlated with high-level of selenol under hypoxic conditions. We believe that this nanosensor could serve as a powerful tool for monitoring selenol and exploring the physiological function of selenol in a variety of physiological and pathological contexts and that the probe-designed strategy will provide a new platform for research on relevant selenium chemistry.Download high-res image (232KB)Download full-size image
Co-reporter:Bing Yang;Qikun Zhang;Xiaoye Ma;Junqing Kang;Jingmin Shi
Nano Research 2016 Volume 9( Issue 7) pp:1879-1890
Publication Date(Web):2016 July
DOI:10.1007/s12274-016-1080-3
In this paper, we describe the facile and effective preparation of a series of cobalt-doped Fe3O4 nanocatalysts via chemical coprecipitation in an aqueous solution. The catalyst allowed the hydrogenation of chloronitrobenzenes to chloroanilines (CAs) to proceed at low temperatures in absolute water and at atmospheric pressure, resulting in approximately 100% yield and selectivity. Several factors that influence the yield of CAs were investigated. The results showed that the suitable dosage of the catalyst was ~10 mol.% of the substrate, and the optimal reaction time, reaction temperature, and reaction pressure were 20 min, 80 °C, and atmospheric pressure, respectively. Under the optimal reaction conditions, the CA yield was as high as 98.4%, and the nitro reduction rate reached 100%, which indicates the excellent selectivity of the homemade catalyst. This process also overcomes the environmental pollution harms associated with the traditional process.
Co-reporter:Min Hong, Lidan Xu, Qingwang Xue, Lu Li, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 24) pp:
Publication Date(Web):November 23, 2016
DOI:10.1021/acs.analchem.6b03108
A novel enzyme-free signal amplification-based assay for highly sensitive in situ fluorescence imaging and detection of intracellular telomerase activity was developed by using a gold nanoflare probe-triggered mimic-hybridization chain reaction (mimic-HCR) coupled with a graphene oxide (GO) surface-anchored fluorescence signal readout pathway. The nanoflare probe consists of gold nanoparticles (AuNPs) functionalized with a dense shell of nucleic acid sequences by Au–S bond formation. The nucleic acid sequence is composed of three segments: a long thiol-labeled sequence (HS-DNA) and two short sequences (a telomerase primer sequence, “Primer-DNA”, and an FAM-terminated reporter sequence, “Flare-DNA”), both of which are complementary to HS-DNA. The mimic-HCR system is formed by two FAM-modified hairpin sequences that are adsorbed on GO. Upon endocytosis of the AuNP/GO combinatorial probe, the Primer-DNA can be extended by intracellular telomerase at its 3′ end to produce the telomeric repeated sequence, which leads to inner chain substitution and not only releases the Flare-DNA to turn on the fluorescence of FAM but also initiates the subsequent signal amplification and enrichment for the mimic-HCR system anchored on GO. The proposed approach can sensitively detect telomerase activity in living cells, distinguish normal cells from cancer cells, and monitor the change in telomerase activity in response to a telomerase inhibitor.
Co-reporter:Baocun Zhu, Ping Li, Wei Shu, Xin Wang, Caiyun Liu, Yue Wang, Zuokai Wang, Yawei Wang, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 24) pp:
Publication Date(Web):November 25, 2016
DOI:10.1021/acs.analchem.6b04392
Hypochlorous acid (HOCl) acts as a weak acid distributed mainly in acidic organelle lysosomes of phagocytes and plays a crucial role in the immune defense. The elaborate interrelation between the variations of HOCl levels in lysosomes and different physiological and pathological processes remains unclear. Thus, the accurate determination of lysosomal HOCl in living cells and in vivo is very important. Because of extremely low concentration and difficulty in distinguishing HOCl from OCl– under the physiological environment, it is still a great challenge to specifically monitor the intracellular intrinsic HOCl levels without exogenous stimulation, which impedes an exact understanding of its biological roles. In this paper, based on the electrophilic addition of Cl+ to sulfide moiety, we have developed a two-photon fluorescent probe O-(N-butyl-1,8-naphthalimide)-4-yl-N,N-dimethylthiocarbamate (NDMTC) for the specific determination of HOCl over OCl– and other bioactive molecules. Our results show that NDMTC possesses a detection limit of 7.6 pM, and it is the first fluorescent probe for detecting HOCl at the picomolar level. Furthermore, by introducing an alkylmorpholine group to the NDMTC framework, the lysosome-targetable derivative Lyso-NDMTC was obtained, and its ability to image HOCl in the lysosome organelles was clearly confirmed. Combined with two-photon fluorescence imaging of background suppression and deeper tissue penetration, NDMTC and Lyso-NDMTC were used to successfully visualize intracellular native HOCl and discern tumor tissue in mice. This study offers two perfect fluorescence imaging probes for further investigation of pathological roles of HOCl in various diseases.
Co-reporter:Limin Yang, Yanfei Ren, Wei Pan, Zhengze Yu, Lili Tong, Na Li, and Bo Tang
Analytical Chemistry 2016 Volume 88(Issue 23) pp:
Publication Date(Web):November 2, 2016
DOI:10.1021/acs.analchem.6b03701
MicroRNAs (miRNAs) and reactive oxygen species (ROS) are concurrently implicated in heart ischemia-reperfusion (IR) injury. There may exist mutual cross-talk between miRNAs and ROS in cardiac IR injury process. In this study, we developed a novel crown-like silica@polydopamine-DNA-CeO2 nanocomposite by assembly of silica@polydopamine-DNA1 nanoparticles decorated with satellite CeO2-DNA2 nanoparticles for detecting and imaging of microRNA-21 (miR-21) and hydrogen peroxide (H2O2) in simulated IR injury in living cells and in vivo. The miRNA-21 was found to be regulated by H2O2 via PI3K/AKT signaling pathway for the first time in H9C2 cells in simulated ischemia-reperfusion injury. H2O2 and miRNA-21 are overproduced during mimicked heart ischemia-reperfusion injury, suggesting that they are closely related to reperfusion injury. All these results reveal that there is definite cross-talk between miR-21 and H2O2 in IR injury. The current method can provide a promising strategy to further explore the interplaying roles between ROS and miRNAs in other pathological processes.
Co-reporter:Guanwei Cui, Wen Wang, Mingyue Ma, Junfeng Xie, Xifeng Shi, Ning Deng, Jianping Xin, and Bo Tang
Nano Letters 2015 Volume 15(Issue 11) pp:7199-7203
Publication Date(Web):October 5, 2015
DOI:10.1021/acs.nanolett.5b01581
An IR-driven photocatalytic water splitting system based on WO2–NaxWO3 (x > 0.25) hybrid conductor materials was established for the first time; this system can be directly applied in seawater. The WO2–NaxWO3 (x > 0.25) hybrid conductor material was readily prepared by a high-temperature reduction process of semiconductor NaxWO3 (x < 0.25) nanowire bundles. A novel ladder-type carrier transfer process is suggested for the established IR-driven photocatalytic water splitting system.
Co-reporter:Xuan Kuang, Yu Ma, Caiyun Zhang, Hao Su, Jine Zhang and Bo Tang
Chemical Communications 2015 vol. 51(Issue 27) pp:5955-5958
Publication Date(Web):25 Feb 2015
DOI:10.1039/C5CC00733J
We describe for the first time a convenient technique to prepare helical CdS nanotubes, with a MOF as the template. The prepared helical CdS nanotubes were remarkably sensitive to D/L-aspartic acid (Asp) and can be used as a potential sensor for enantioselective recognition of D/L-Asp.
Co-reporter:Lu Li, Xiuli Wang, Qingling Li, Pengyuan Liu, Kehua Xu, Hao Chen and Bo Tang
Chemical Communications 2015 vol. 51(Issue 56) pp:11317-11320
Publication Date(Web):02 Jun 2015
DOI:10.1039/C5CC03157E
A novel accurate method was developed for simultaneous quantitative comparison of GSH, Cys and Hcy in normal cells and cancer cells using new NPSP isotope probes based on LC/ESI-MS.
Co-reporter:Xinyuan Xia, Ning Deng, Guanwei Cui, Junfeng Xie, Xifeng Shi, Yingqiang Zhao, Qian Wang, Wen Wang and Bo Tang
Chemical Communications 2015 vol. 51(Issue 54) pp:10899-10902
Publication Date(Web):27 May 2015
DOI:10.1039/C5CC02589C
NIR light induced H2 evolution was realized by metal-free photocatalysis for the first time. The considerable H2 production at 808 nm and large promotion of the photocatalytic activity in both UV-Vis and Vis regions originated from the synergistic effect on spectral and electronic coupling of g-C3N4 nanosheets and carbon quantum dots.
Co-reporter:Hongyan Zhang, Zhenzhen Jia, Chuanchen Wu, Liguo Zang, Guiwen Yang, Zhenzhen Chen, and Bo Tang
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 36) pp:20477
Publication Date(Web):August 28, 2015
DOI:10.1021/acsami.5b06874
Detection of circulating tumor cells (CTCs) could be used as a “liquid biopsy” for tracking the spread of cancer. In vitro detection methods based on blood sampling and in vitro CTC capture often suffer from the small sampling volume and sampling error. Here, the in vivo capture of CTCs based on transfusion with a surface-modified vein indwelling needle is proposed. When the needle was applied to transfusion in the vein, the simultaneous capture of CTCs was performed. To investigate the actual capture efficiency of the in vivo capture method, labeled MCF-7 cells were directly injected into the veins of rabbits, wild type mice, and nude mice and could be successfully captured. Two of 5 MCF-7 cells injected into the veins of nude mice were successfully captured. To investigate the CTC capture of mouse tumor model and compare with the in vitro method, mice were subcutaneous inoculated with metastatic 4T1 cells. Seven and 21 days after inoculation, CTCs were captured for the first time using in vivo and in vitro methods, respectively. This predicted that the in vivo method could be more suitable for use of early diagnosis of cancer than the in vitro method. As CTC capture can be performed at the same time as transfusion and does not cause further bodily harm, it would be easily accepted by patients. This efficient, simple, and less damaging method involving the use of a vein indwelling needle could be popularized easily in the clinic.Keywords: cancer diagnosis; circulating tumor cell; in vivo; transfusion; vein indwelling needle
Co-reporter:Wei Zhang, Wei Liu, Ping Li, Junqing kang, Jiaoyang Wang, Hui Wang and Bo Tang
Chemical Communications 2015 vol. 51(Issue 50) pp:10150-10153
Publication Date(Web):12 May 2015
DOI:10.1039/C5CC02537K
Herein, we have developed a novel reversible two-photon fluorescent probe that is well suited for monitoring HOCl levels selectively and instantaneously. Results showed the reversible and instantaneous responses of the probe towards intracellular HOCl. Moreover, the probe was successfully applied to the imaging of the HOCl levels in zebrafish and mice via two-photon imaging.
Co-reporter:Wen Zhang, Xin Wang, Ping Li, Fang Huang, Hui Wang, Wei Zhang and Bo Tang
Chemical Communications 2015 vol. 51(Issue 47) pp:9710-9713
Publication Date(Web):06 May 2015
DOI:10.1039/C5CC01670C
We report a new reversible fluorescent two-photon (TP) probe (PY-CA) with high TP absorption cross section and pH-independent fluorescence response, which allow monitoring of O2˙− fluxes dynamically, selectively and sensitively. The imaging results indicate that O2˙− at high levels can shorten the life of Caenorhabditis elegans.
Co-reporter:Fanpeng Kong, Xiaoyue Meng, Ranran Chu, Kehua Xu and Bo Tang
Chemical Communications 2015 vol. 51(Issue 32) pp:6925-6927
Publication Date(Web):12 Mar 2015
DOI:10.1039/C5CC01130B
Based on a unique elimination reaction prompted by the iodide ion, a novel turn-on fluorescence probe (HCy-OMe-Br) has been developed for the first time. The probe emits in the near infrared region with a large Stokes shift, and can respond rapidly to iodide with high selectivity and sensitivity.
Co-reporter:Fanpeng Kong, Bo Hu, Yan Gao, Kehua Xu, Xiaohong Pan, Fang Huang, Qiuling Zheng, Hao Chen and Bo Tang
Chemical Communications 2015 vol. 51(Issue 15) pp:3102-3105
Publication Date(Web):09 Jan 2015
DOI:10.1039/C4CC06359G
A novel fluorescence probe (HB) has been designed and synthesized to image selenol in living cells and in vivo for the first time, and used to investigate the Na2SeO3 anticancer mechanism in HepG2 cells.
Co-reporter:Limin Yang, Na Li, Wei Pan, Zhengze Yu, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 7) pp:3678
Publication Date(Web):March 4, 2015
DOI:10.1021/ac503975x
Mitochondrial reactive oxygen species (ROS) and pH fluctuations are closely correlated with mitochondrial dysfunctions, which are implicated in various human diseases including neurodegenerative disorders and cancers. Simultaneously monitoring the changes of ROS and pH of mitochondria remains a major challenge in the mitochondrial biology. In this study, we develop a novel mitochondria-targeted fluorescent nanosensor for real-time imaging of the fluctuations of hydrogen peroxide (H2O2) and pH in living cells. The fluorescence probes for detecting pH and H2O2 were loaded in the small-sized mesoporous silica nanoparticles (MSN). Then the polyethylenimine was attached to cap the pores of MSN, the triphenylphosphonium was further modified to target mitochondria in living cells. Confocal fluorescence imaging indicated that the nanosensor could effectively target mitochondria and successfully achieved real-time imaging of mitochondrial H2O2 and pH fluctuations in living cells. Notably, this is a single nanosensing system that is capable of visualizing multiple subcellular analytes at the same time and position by multicolor fluorescence imaging. The current approach can provide a promising tool to investigate the interplaying roles of various subcellular analytes in living cells.
Co-reporter:Chunxiang Li, Hongyang Wang, Jing Shen, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 8) pp:4283
Publication Date(Web):March 27, 2015
DOI:10.1021/ac5047032
Photoactive material is the most crucial factor which intimately determines analytical performances of the photoelectrochemical sensor. On the basis of the high affinity of dipyrido [3,2-a:2′,3′-c] phenazine (dppz) with DNA helix, a novel photoactive intercalator, [(ppy)2Ir(dppz)]+PF6–(ppy = 2-phenylpyridine and dppz = dipyrido [3,2-a:2′,3′-c] phenazine) was prepared and characterized by UV–vis absorption spectroscopy, fluorescence spectroscopy, and cyclic voltammetry. The photoelectrochemical properties of the as-prepared iridium(III) complex immobilized on the ITO electrode was investigated. Either cathodic or anodic photocurrent generation can be observed when triethanolamine (TEOA) or dissolved O2 is used as a sacrificial electron donor/acceptor, respectively. The probable photocurrent-generation mechanisms are speculated. A highly sensitive iridium(III) complex-based photoelectrochemical sensor was proposed for DNA detection via hybridization chain reaction (HCR) signal amplification. Under optimal conditions, the biosensor was found to be linearly proportional to the logarithm of target DNA concentration in the range from 0.025 to 100 pmol L–1 with a detection limit of 9.0 fmol L–1 (3σ). Moreover, the proposed sensor displayed high selectivity and good reproducibility, demonstrating efficient and stable photoelectric conversion ability of the Ir(III) complex.
Co-reporter:Lu Li, Jie Feng, Yuanyuan Fan, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 9) pp:4829
Publication Date(Web):April 8, 2015
DOI:10.1021/acs.analchem.5b00204
Trace Zn2+ and Cu2+ in living cells play important roles in the regulation of biological function. It is significant to simultaneously detect the cellular Zn2+ and Cu2+. Here, we present a novel two-color fluorescence nanoprobe based on the DNAzymes for simultaneous imaging of Zn2+ and Cu2+ in living cells. The probe consists of a 13 nm gold nanoparticle, DNAzymes that are specific for Zn2+ and Cu2+, and the substrate strands labeled with fluorophores at the 5′ end and quenchers at the 3′ end. The fluorescence of the fluoreophores is quenched both by the gold nanoparticle and the quencher. After the nanoprobes are transferred into the cells, the substrate strands would be cleaved in the presence of the Zn2+ and Cu2+ target, resulting in disassociation of the shorter DNA fragments containing fluorophores, which produce fluorescence signals correlated with the location and concentration of the Zn2+ and Cu2+. The nanoprobe exhibits high specificity, nuclease stability, and good biocompatibility. Moreover, the nanoprobe can simultaneously monitor the cellular Zn2+ and Cu2+ with an on-site manner, providing the information on localization and concentration of targets, which is significant to further research the Zn2+- and Cu2+-relative cellular events and biological process. The proposed method has shown great potential in the detection of multiple metal ions in living cells, which may help us to better understand the function of metal ions in the fields of biochemistry, molecular biology, and cellular toxicology.
Co-reporter:Lu Li, Ping Li, Juan Fang, Qingling Li, Haibin Xiao, Hui Zhou, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 12) pp:6057
Publication Date(Web):May 14, 2015
DOI:10.1021/acs.analchem.5b00571
Considering the important functions of cellular Na+ and K+ together with their cooperative efforts on various biological processes, it is significant to simultaneously detect Na+ and K+ at a single-cell level. Here, we present a novel method to discriminate and quantify simultaneously Na+ and K+ in single cells using a new near-infrared fluorescent probe associated with microchip electrophoresis. The fluorescent probe selectively responds to both Na+ and K+. The microchip electrophoresis allows accurate single-cell manipulation and effective distinction of Na+ and K+. Based on the method, the concentration of Na+ and K+ in single normal and cancer cells was compared, and the variation of Na+ and K+ in single cancer cells during the early stage of apoptotic volume decrease was monitored, which would help us to better understand the critical roles of Na+ and K+ in malignant cells and apoptosis. This method has paved a new way for the research of the synergistic function of Na+ and K+ in the regulation of various biological processes at a single-cell level.
Co-reporter:Xiaohong Pan, Xiaoting Wang, Liyong Wang, Kehua Xu, Fanpeng Kong, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 14) pp:7092
Publication Date(Web):June 18, 2015
DOI:10.1021/acs.analchem.5b00820
Vitamin C (ascorbic acid; AA) is a well-known reducing agent and has been evaluated for its antitumor activity. However, the mechanism for its antitumor action remains unclear. Tracking the metabolism of AA may help to elucidate its antitumor mechanism. In this study, a near-infrared fluorescent probe (Arg-Cy) for monitoring the metabolic products of AA in living cells was developed based on the reaction of the guanidine group in Arg-Cy with the adjacent diketone involved in the metabolites of AA. Consequently, the probe can respond to l-xylosone, a metabolite of AA, with high selectivity and sensitivity and was successfully used to visualize the real-time changes of l-xylosone levels in living cells incubated under normoxic conditions. Considering that the tumor microenvironment suffers from hypoxia, the l-xylosone levels in the process of HepG2 cell death induced by pharmacological doses of AA were also monitored under hypoxic conditions. Surprisingly, no obvious fluorescence change appeared during this process. Furthermore, detection of the intracellular redox state using a reported H2O2 probe confirmed that AA can be metabolized to l-xylosone only under normoxic conditions due to the oxidative stress, but not under hypoxic conditions. Therefore, we hypothesize that the mechanism for cell death induced by AA under hypoxia is different from that under normoxia. Thus, the developed probe can provide a tool for monitoring the metabolism of AA and may help to clarify the mechanism for the antitumor activity of vitamin C in the tumor microenvironment.
Co-reporter:Wei Zhang, Junqing Kang, Ping Li, Hui Wang, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 17) pp:8964
Publication Date(Web):August 3, 2015
DOI:10.1021/acs.analchem.5b02169
A dual signaling molecule sensor has received increasing attention owing to its ability to read out target analytes with more than one transduction channel and thus make the results more convincing. Here we have developed a dual signaling molecule sensor that is well suited for monitoring hydrogen sulfide (H2S) levels through fluorescence, UV–visible adsorption, and visual mode. Results showed the selective and instantaneous responses of sensor toward intracellular H2S. Moreover, the sensor was successfully applied to imaging of H2S levels in Caenorhabditis elegans (C. elegans) and observed the changes of H2S under starvation of C. elegans. Altogether, the sensor was proved to be a useful tool for tracking H2S levels in cells and in vivo. The merits of two kinds of independent signaling molecules allow us to select different output modes according to the different samples.
Co-reporter:Wei Zhang, Wei Liu, Ping Li, Fang Huang, Hui Wang, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 19) pp:9825
Publication Date(Web):September 9, 2015
DOI:10.1021/acs.analchem.5b02194
Hydrogen peroxide (H2O2) as a reactive oxygen species (ROS) plays a crucial role in oxidative stress and signal transduction of organisms. Currently, a fluorescence probe has proven to be a powerful tool for the H2O2 analysis. However, the common problem is the slow response, causing difficulty in tracking H2O2 in situ. Herein, we describe a novel aggregation-induced emission (AIE) fluorescence probe based on increased polarity of C–B bonds that is well suited for monitoring H2O2 rapidly and selectively. Importantly, the probe was successfully applied to visualize H2O2 levels in living cells, which provides a rapid-response and highly selective fluorescence tool for monitoring of the H2O2 levels in biological process.
Co-reporter:Sujuan Ye, Yanying Wu, Xiaomo Zhai, and Bo Tang
Analytical Chemistry 2015 Volume 87(Issue 16) pp:8242
Publication Date(Web):July 28, 2015
DOI:10.1021/acs.analchem.5b01186
Simultaneous detection of cancer biomarkers holds great promise for the early diagnosis of different cancers. However, in the presence of high-concentration biomarkers, the signals of lower-expression biomarkers are overlapped. Existing techniques are not suitable for simultaneously detecting multiple biomarkers at concentrations with significantly different orders of magnitude. Here, we propose an asymmetric signal amplification method for simultaneously detecting multiple biomarkers with significantly different levels. Using the bifunctional probe, a linear amplification mode responds to high-concentration markers, and quadratic amplification mode responds to low-concentration markers. With the combined biobarcode probe and hybridization chain reaction (HCR) amplification method, the detection limits of microRNA (miRNA) and ATP via surface-enhanced Raman scattering (SERS) detection are 0.15 fM and 20 nM, respectively, with a breakthrough of detection concentration difference over 11 orders of magnitude. Furthermore, successful determination of miRNA and ATP in cancer cells supports the practicability of the assay. This methodology promises to open an exciting new avenue for the detection of various types of biomolecules.
Co-reporter:Hongmin Li;Lu Li;Xu Wang;Qingling Li;Miao Du
Science China Chemistry 2015 Volume 58( Issue 5) pp:825-829
Publication Date(Web):2015 May
DOI:10.1007/s11426-015-5396-8
We present a more accurate method for the quantification of superoxide anion (O2·−) and hydrogen peroxide (H2O2) simultaneously in human HepG2 cell extracts. After the xanthine/xanthine oxidase system was added into cell extract which was devoid of O2·− and H2O2, steady-state and in-situ produced O2·− and H2O2 by xanthine/xanthine oxidase system was labeled by fluorescent probes and subsequently separated by microchip electrophoresis. Based on this method, two differential equations with the calibration coefficients were established for O2·− and H2O2, respectively. Using the established dual-calibration coefficients, we obtained the calibrated concentrations of O2·− and H2O2 that produced in human HepG2 cells, which were lower (0.66±0.03 and 0.82±0.04 µmol/L for O2·− and H2O2, respectively) than that (0.85±0.03 and 0.96±0.03 µmol/L for O2·− and H2O2, respectively) obtained from statutory working curve. The proposed dual-calibration coefficient protocol takes into account both the complex matrix effect of the biological system and real time decaying of O2·− and H2O2, providing a method with higher accuracy.
Co-reporter:Dr. Xiaohong Pan ;Ziye Liang;Jing Li;Shanshan Wang;Dr. Fanpeng Kong; Kehua Xu; Bo Tang
Chemistry - A European Journal 2015 Volume 21( Issue 5) pp:2117-2122
Publication Date(Web):
DOI:10.1002/chem.201405349
Abstract
Vicinal-sulfydryl-containing peptides/proteins (VSPPs) play a crucial role in human pathologies. Fluorescent probes that are capable of detecting intracellular VSPPs in vivo would be useful tools to explore the mechanisms of some diseases. In this study, by regulating the spatial separation of two maleimide groups in a fluorescent dye to match that of two active cysteine residues contained in the conserved amino acid sequence (–CGPC–) of human thioredoxin, two active-site-matched fluorescent probes, o-Dm-Ac and m-Dm-Ac, were developed for real-time imaging of VSPPs in living cells. As a result, the two probes can rapidly respond to small peptide models and reduced proteins, such as WCGPCK (W-6), WCGGPCK (W-7), and WCGGGPCK (W-8), reduced bovine serum albumin (rBSA), and reduced thioredoxin (rTrx). Moreover, o-Dm-Ac displays a higher binding sensitivity with the above-mentioned peptides and proteins, especially with W-7 and rTrx. Furthermore, o-Dm-Ac was successfully used to rapidly and directly detect VSPPs both in vitro and in living cells. Thus, a novel probe-design strategy was proposed and the synthesized probe applied successfully in imaging of target proteins in situ.
Co-reporter:Li-li Tong, Zhen-zhen Chen, Zhong-yao Jiang, Miao-miao Sun, Lu Li, Ju Liu, Bo Tang
Biosensors and Bioelectronics 2015 Volume 72() pp:51-55
Publication Date(Web):15 October 2015
DOI:10.1016/j.bios.2015.04.087
•Fe3O4 NPs as an efficient fluorescence quencher for F*-ssDNA was proposed.•A new fluorescent method for sensitive detection of pyrophosphate anion in the synovial fluid was developed.•The sensing relies on the competitive coordination interaction of Fe3O4 NPs between PPi and F*-ssDNA.•The protocol exhibits excellent selectivity for PPi over other phosphate-containing compounds.•The system is simple in design and convenient in operation.In this work, a new fluorescent method for sensitive detection of pyrophosphate anion (P2O74−, PPi) in the synovial fluid was developed using fluorophore labeled single-stranded DNA-attached Fe3O4 NPs. The sensing approach is based on the strong affinity of PPi to Fe3O4 NPs and highly efficient fluorescent quenching ability of Fe3O4 NPs for fluorophore labeled single-stranded DNA. In the presence of PPi, the fluorescence would enhance dramatically due to desorption of fluorophore labeled single-stranded DNA from the surface of Fe3O4 NPs, which allowed the analysis of PPi in a very simple manner. The proposed sensing system allows for the sensitive determination of PPi in the range of 2.0×10−7–4×10−6 M with a detection limit of 76 nM. Importantly, the protocol exhibits excellent selectivity for the determination of PPi over other phosphate-containing compounds. The method was successfully applied to the determination of PPi in the synovial fluid, which suggests our proposed method has great potential for diagnostic purposes.
Co-reporter:Zhengze Yu, Qiaoqiao Sun, Wei Pan, Na Li, and Bo Tang
ACS Nano 2015 Volume 9(Issue 11) pp:11064
Publication Date(Web):October 12, 2015
DOI:10.1021/acsnano.5b04501
Photodynamic therapy (PDT) is a well-established modality for cancer therapy, which locally kills cancer cells when light irradiates a photosensitizer. However, conventional PDT is often limited by the extremely short lifespan and severely limited diffusion distance of reactive oxygen species (ROS) generated by photosensitizer, as well as the penetration depth of visible light activation. Here, we develop a near-infrared (NIR) triggered nanophotosensitizer based on mitochondria targeted titanium dioxide-coated upconversion nanoparticles for PDT against cancer. When irradiated by NIR laser, the nanophotosensitizer could produce ROS in mitochondria, which induced the domino effect on ROS burst. The overproduced ROS accumulated in mitochondria, resulting in mitochondrial collapse and irreversible cell apoptosis. Confocal fluorescence imaging indicated that the mitochondrial targeting and real-time imaging of ROS burst could be achieved in living cells. The complete removal of tumor in vivo confirmed the excellent therapeutic effect of the nanophotosensitizer.Keywords: cancer therapy; domino effect; nanophotosensitizer; near-infrared; reactive oxygen species;
Co-reporter:Dr. Wei Pan;Huijun Yang;Dr. Na Li;Limin Yang ; Bo Tang
Chemistry - A European Journal 2015 Volume 21( Issue 16) pp:6070-6073
Publication Date(Web):
DOI:10.1002/chem.201500365
Abstract
Simultaneous monitoring of multiple tumour markers is of great significance for improving the accuracy of early cancer detection. In this study, a fluorescence nanoprobe has been prepared that can simultaneously monitor and visualize multiple mRNAs and matrix metalloproteinases (MMPs) in living cells. Confocal fluorescence imaging results indicate that the nanoprobe could effectively distinguish between cancer cells and normal cells even if one tumour maker of normal cells was overexpressed. Furthermore, it can detect changes in the expression levels of mRNAs and MMPs in living cells. The current approach could provide new tools for early cancer detection and monitoring the changes in expression levels of biomarkers during tumour progression.
Co-reporter:Hui Xu, Qian Li, Lihua Wang, Yao He, Jiye Shi, Bo Tang and Chunhai Fan
Chemical Society Reviews 2014 vol. 43(Issue 8) pp:2650-2661
Publication Date(Web):06 Jan 2014
DOI:10.1039/C3CS60309A
Nanomaterials with unique optical properties have shown great promise as probes for cellular imaging. Based on these properties, a wide range of plasmonic, fluorescent and Raman probes have been designed and prepared. Nanomaterials of different sizes and shapes have also been functionalized with various types of biomolecules, such as antibodies, DNA or RNA, which are actively exploited to realize targeted imaging. In this review, we will summarize recent advances in using functional nanomaterials for imaging, primarily cellular imaging. These nanomaterials are categorized based on their conducting properties, i.e. conductors, semiconductors and insulators.
Co-reporter:Hongyan Zhang, Yanhong Wang, Qingling Li, Fumiao Zhang and Bo Tang
Chemical Communications 2014 vol. 50(Issue 53) pp:7024-7027
Publication Date(Web):07 May 2014
DOI:10.1039/C4CC02342K
Using anti-EpCAM antibody modified magnetic microbeads allowed us to simultaneously apply size-amplification and magnetic labelling of CTCs to the capture and purification of CTCs by membrane filtration and immune-magnetic separation. High purity capture (>98%), rapid (<2 hours) and simple detection of CTCs were realized.
Co-reporter:Ruirui Zhang, Lu Li, Jie Feng, Lili Tong, Qian Wang, and Bo Tang
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 13) pp:9932
Publication Date(Web):May 30, 2014
DOI:10.1021/am502463h
A versatile triggered release system by capping the cyclodextrin-modified gold nanoparticle onto the mesoporous silica was fabricated. The as-designed nanocontainers combine the merits of multiple molecules loading and sequential release by natural circulation manner and light initiation.Keywords: controlled release; cyclodextrin; gold nanoparticles; light initiation; mesoporous silica; stimuli responsive
Co-reporter:Xu Wang, Jianzheng Lv, Xueying Yao, Yong Li, Fang Huang, Mengmeng Li, Jie Yang, Xiuyun Ruan and Bo Tang
Chemical Communications 2014 vol. 50(Issue 97) pp:15439-15442
Publication Date(Web):16 Oct 2014
DOI:10.1039/C4CC06637E
Here we report the synthesis and screening of Cy-3-NO2 that showed simultaneous fluorescence sensing ability towards glutathione and cysteine under single excitation, and its application in living cell imaging.
Co-reporter:Sujuan Ye, Yanying Wu, Wen Zhang, Na Li and Bo Tang
Chemical Communications 2014 vol. 50(Issue 66) pp:9409-9412
Publication Date(Web):01 Jul 2014
DOI:10.1039/C4CC03988B
A novel surface-enhanced Raman scattering (SERS) detection system is developed for proteins and nucleic acids based on a triple-helix molecular switch for multiple cycle signal amplification, achieving high sensitivity, universality, rapid analysis, and high selectivity.
Co-reporter:Wen Gao, Wenhua Cao, Huaibin Zhang, Ping Li, Kehua Xu and Bo Tang
Chemical Communications 2014 vol. 50(Issue 60) pp:8117-8120
Publication Date(Web):05 Jun 2014
DOI:10.1039/C4CC03793F
We have developed multifunctional Au–ZnO hybrid nanoparticles (NPs) for targeted induction lysosomal membrane permeabilization (LMP)-dependent apoptosis in cancer cells and real-time imaging.
Co-reporter:Na Li, Huijun Yang, Wei Pan, Wei Diao and Bo Tang
Chemical Communications 2014 vol. 50(Issue 56) pp:7473-7476
Publication Date(Web):16 May 2014
DOI:10.1039/C4CC01009D
We have established a tumour marker activated nanocarrier that can respond to the intracellular mRNA, allowing multimodal cancer cell imaging and therapy.
Co-reporter:Zhengze Yu, Na Li, Peipei Zheng, Wei Pan and Bo Tang
Chemical Communications 2014 vol. 50(Issue 26) pp:3494-3497
Publication Date(Web):10 Feb 2014
DOI:10.1039/C3CC49183H
We report a novel strategy to construct temperature-responsive nanocarriers for controlled release based on mesoporous silica and reversible single-stranded DNA valves.
Co-reporter:Xuan Kuang, Yu Ma, Hao Su, Jine Zhang, Yu-Bin Dong, and Bo Tang
Analytical Chemistry 2014 Volume 86(Issue 2) pp:1277
Publication Date(Web):December 31, 2013
DOI:10.1021/ac403674p
Homochiral metal–organic frameworks with fine-tuned pore sizes/walls and large surface areas are promising porous materials for enantioseparation considering the traditional zeolite molecular sieves have no chirality. Using enantiopure pyridyl-functionalized salen [(N-(4-Pyridylmethyl)-l-leucine·HBr)] as a starting material, we have prepared a noninterpenetrated three-dimensional homochiral metal organic framework {[ZnLBr]·H2O}n, which was further used as a chiral stationary phase for high-performance liquid chromatography to enantioseparate racemic drugs, showing excellent performances in enantioseparation of drugs. The metal–organic framework can be regarded as a novel molecular sieve-like material with a chiral separation function based on the relative sizes of the chiral channels and the resolved molecules.
Co-reporter:Shufeng Liu, Ying Lin, Li Wang, Tao Liu, Chuanbin Cheng, Wenji Wei, and Bo Tang
Analytical Chemistry 2014 Volume 86(Issue 8) pp:4008
Publication Date(Web):March 24, 2014
DOI:10.1021/ac500426b
Homogenous electrochemical biosensor has attracted substantial attention owing to its simplicity, rapid response, and improved recognition efficiency compared with heterogeneous biosensor, but the relatively low detection sensitivity and the limited detection analytes prohibit its potential applications. To address these issues, herein, a simple, rapid, isothermal, and ultrasensitive homogeneous electrochemical DNA biosensing platform for target DNA and protein detection has been developed on the basis of an exonuclease III (Exo III)-aided autocatalytic target recycling strategy. A ferrocene-labeled hairpin probe (HP1) is ingeniously designed, which contains a protruding DNA fragment at 3′-termini as the recognition unit for target DNA. Also, the DNA fragment that could be used as secondary target analogue was introduced, but it was caged in the stem region of HP1. In the presence of target DNA, its recognition with the protruding fragment of HP1 triggered the Exo III cleavage process, accompanied with the target recycling and autonomous generation of secondary target analogues. This accordingly resulted into the autonomous accumulation of ferrocene-labeled mononucleotide, inducing a distinct increase in the electrochemical signal owing to its elevated diffusivity toward indium tin oxide (ITO) electrode surface. The autocatalytic biosensing system was further extended for protein detection by advising an aptamer hairpin switch with the use of thrombin as a model analyte. The current developed autocatalytic and homogeneous strategy provided an ultrasensitive electrochemical detection of DNA and thrombin down to the 0.1 and 5 pM level, respectively, with a high selectivity. It should be further used as a general autocatalytic and homogeneous strategy toward the detection of a wide spectrum of analytes and may be associated with more analytical techniques. Thus, it holds great potential for the development of ultrasensitive biosensing platform for the applications in bioanalysis, disease diagnostics, and clinical biomedicine.
Co-reporter:Na Li, Yanhua Li, Yaoyao Han, Wei Pan, Tingting Zhang, and Bo Tang
Analytical Chemistry 2014 Volume 86(Issue 8) pp:3924
Publication Date(Web):March 21, 2014
DOI:10.1021/ac5000587
The development of a specific reaction of nanomaterials and reactive species is of fundamental importance for the determination of biomolecules. Here we report a novel nanoprobe for detection and imaging of ascorbic acid (AA) in living cells and in vivo based on the specific reaction of cobalt oxyhydroxide (CoOOH) and AA. Persistent luminescence nanoparticles (PLNPs) were used as the luminescence unit, and CoOOH nanoflakes served as the quencher. When CoOOH was modified on the surface of the PLNPs, the luminescence of the PLNPs was efficiently quenched by the CoOOH. In the presence of AA, CoOOH was reduced to Co2+ and the luminescence of PLNPs was restored. The nanoprobe showed high selectivity and an instantaneous response. The luminescence property permits detection and imaging without external excitation, which could effectively avoid background noise and scattering of light from biological matrixes produced by in situ excitation. The current strategy provides an effective platform for monitoring and imaging reactive species in living cells and in vivo.
Co-reporter:Lu Li, Qian Wang, Jie Feng, Lili Tong, and Bo Tang
Analytical Chemistry 2014 Volume 86(Issue 10) pp:5101
Publication Date(Web):April 29, 2014
DOI:10.1021/ac500881p
Membrane proteins play vital roles in numerous physiological functions. Recently, they have been considered as candidate biomarkers for cancer and recognized as major drug targets. So, accurate, sensitive, and high-throughput quantitative detection of the membrane proteins is crucial for better understanding their roles in cancer cells and further validating their function in clinical research. Here, we report a highly sensitive and homogeneous detection of membrane protein on single living cells by aptamer and nicking enzyme assisted fluorescence signal amplification in microfluidic droplets. The homogeneous reaction based on the membrane protein-triggered conformation alteration of hairpin probe can improve the detection accuracy with elimination of several washing and separation steps. The microfluidic system provides a high-throughput platform for the detection of a single cell, and the highly monodisperse droplet can function as an independent microreactor for the aptamer and nicking enzyme assisted fluorescence signal amplification, coordinating with the small volume of the confined space (a droplet), increased reaction rate, and highly sensitive detection of membrane protein on single cell can be reached.
Co-reporter:Haiyun Liu, Lu Li, Qian Wang, Lili Duan, and Bo Tang
Analytical Chemistry 2014 Volume 86(Issue 11) pp:5487
Publication Date(Web):May 12, 2014
DOI:10.1021/ac500752t
MicroRNAs (miRNAs) play significant roles in a diverse range of biological progress and have been regarded as biomarkers and therapeutic targets in cancer treatment. Sensitive and accurate detection of miRNAs is crucial for better understanding their roles in cancer cells and further validating their function in clinical diagnosis. Here, we developed a stable, sensitive, and specific miRNAs detection method on the basis of cooperative amplification combining with the graphene oxide (GO) fluorescence switch-based circular exponential amplification and the multimolecules labeling of SYBR Green I (SG). First, the target miRNA is adsorbed on the surface of GO, which can protect the miRNA from enzyme digest. Next, the miRNA hybridizes with a partial hairpin probe and then acts as a primer to initiate a strand displacement reaction to form a complete duplex. Finally, under the action of nicking enzyme, universal DNA fragments are released and used as triggers to initiate next reaction cycle, constituting a new circular exponential amplification. In the proposed strategy, a small amount of target miRNA can be converted to a large number of stable DNA triggers, leading to a remarkable amplification for the target. Moreover, compared with labeling with a 1:1 stoichiometric ratio, multimolecules binding of intercalating dye SG to double-stranded DNA (dsDNA) can induce significant enhancement of fluorescence signal and further improve the detection sensitivity. The extraordinary fluorescence quenching of GO used here guarantees the high signal-to-noise ratio. Due to the protection for target miRNA by GO, the cooperative amplification, and low fluorescence background, sensitive and accurate detection of miRNAs has been achieved. The strategy proposed here will offer a new approach for reliable quantification of miRNAs in medical research and early clinical diagnostics.
Co-reporter:Yu Ma, Hao Su, Xuan Kuang, Xiangyuan Li, Tingting Zhang, and Bo Tang
Analytical Chemistry 2014 Volume 86(Issue 22) pp:11459
Publication Date(Web):October 24, 2014
DOI:10.1021/ac503622n
Hydrogen sulfide (H2S) has been regarded as the third important gaseous signaling molecule involved in human physiological and pathological processes. Due to the high reactive and diffusible properties of H2S, real-time detection of H2S fluctuations in living biological specimens is crucial. Here, we present a Cu(II)-metalated 3D porous nanoscale metal–organic framework (nano-MOF) {CuL[AlOH]2}n (PAC; H6L = meso-tetrakis(4-carboxylphenyl)porphyrin) and successfully employ this nano-MOF as a novel heterogeneous fluorescence probe for H2S detection. As far as we know, nano-MOFs have never been used as selective fluorescence probes for H2S detection. On the basis of the advantages of nano-MOF materials, this biocompatible nano-MOF probe exhibits rapid response, excellent selectivity, and hypotoxicity in in situ detection of H2S and represents the most sensitive fluorescence probe for selective H2S detection under physiological pH. In addition, confocal imaging was achieved successfully in living cells.
Co-reporter:Yingqiang Zhao, Ming-Yue Ma, Guan-Wei Cui, Xi-Feng Shi, Feng-Yun Han, Xin-Yuan Xia, Bo Tang
Carbon 2014 Volume 73() pp:333-337
Publication Date(Web):July 2014
DOI:10.1016/j.carbon.2014.02.071
Dumbbell-like carbonaceous sodium hexagonal tungsten bronze (Na-HTB) materials are constructed as model photocatalysts to show the importance of carbon distribution for the photocatalysis of hybrid nanostructures. It is demonstrated that partially carbon coated on the ends of Na-HTB nanowire bundles shows better photoactivity than bare Na-HTB and overall carbon coated Na-HTB. Photoelectrochemistry measurements such as photocurrent measurement, electrochemical impedance spectroscopy (EIS) and Voltage of open-circuit (Voc) decay experiments are carried out to clarify the influence of carbon distribution on the photoactivity of carbonaceous Na-HTB materials, and the results show that the enhancement of photoactivity is attributed to the efficient spacial charge separation.
Co-reporter:Jinye Niu, Xu Wang, Jianzheng Lv, Yong Li, Bo Tang
TrAC Trends in Analytical Chemistry 2014 Volume 58() pp:112-119
Publication Date(Web):June 2014
DOI:10.1016/j.trac.2014.02.013
•We review the advancement of luminescent nanoprobes for in-vivo bioimaging.•We classify the luminescent nanoprobes described according to nanoluminophore.•We explain the challenges of this research field and give perspectives on it.Luminescent bioimaging, based on nanoprobes, is highly selective, sensitive, and non-invasive, and it has become a powerful tool for visualizing tissues with cellular or sub-cellular resolution and mapping of molecular events. Taking into account the progressive increase in research on luminescent nanoprobe-based bioimaging, especially in living animals, we review recent advances in this area. Research is classified according to the nanoluminophore into quantum dots, upconversion nanophosphors, dye-doped nanoparticles (NPs), and other luminescent nanoprobes, including gold nanoclusters, carbon-based nanomaterials, persistent luminescence NPs, and porous silicon NPs. We demonstrate the progress and the challenges of applying luminescent nanoprobes from basic to clinical research, which is supposed to benefit the exploitation and the development of high-performance nanoprobes for in-vivo bioimaging.
Co-reporter:Dr. Wei Zhang;Wei Liu; Ping Li;Haibin Xiao;Dr. Hui Wang ; Bo Tang
Angewandte Chemie International Edition 2014 Volume 53( Issue 46) pp:12489-12493
Publication Date(Web):
DOI:10.1002/anie.201405634
Abstract
Glycoproteins are closely associated with the occurrence of diverse diseases, and they have been used as biomarkers and therapeutic targets in clinical diagnostics. Currently, mass spectrometry has proven to be a powerful tool for glycoprotein analysis, but it is almost impossible to directly identify glycoproteins without the preparation and pretreatment of samples. Furthermore, biological samples, especially proteins, are damaged by this process. Herein, we describe a novel fluorescence nanosensor based on a molecularly imprinted spatial structure and boronate affinity that is well-suited for monitoring glycoproteins selectively. Results showed that the recognition performance of the nanosensor for glycoproteins was regulated by controlling the pH value and temperature. Moreover, the nanosensor was successfully applied to the detection of HRP in biological fluids. This study provides a facile and efficient fluorescence tool for glycoprotein detection in clinical diagnostics.
Co-reporter:Dr. Wei Zhang;Wei Liu; Ping Li;Haibin Xiao;Dr. Hui Wang ; Bo Tang
Angewandte Chemie 2014 Volume 126( Issue 46) pp:12697-12701
Publication Date(Web):
DOI:10.1002/ange.201405634
Abstract
Glycoproteins are closely associated with the occurrence of diverse diseases, and they have been used as biomarkers and therapeutic targets in clinical diagnostics. Currently, mass spectrometry has proven to be a powerful tool for glycoprotein analysis, but it is almost impossible to directly identify glycoproteins without the preparation and pretreatment of samples. Furthermore, biological samples, especially proteins, are damaged by this process. Herein, we describe a novel fluorescence nanosensor based on a molecularly imprinted spatial structure and boronate affinity that is well-suited for monitoring glycoproteins selectively. Results showed that the recognition performance of the nanosensor for glycoproteins was regulated by controlling the pH value and temperature. Moreover, the nanosensor was successfully applied to the detection of HRP in biological fluids. This study provides a facile and efficient fluorescence tool for glycoprotein detection in clinical diagnostics.
Co-reporter: Ping Li;Shan Zhang;Nannan Fan;Dr. Haibin Xiao;Dr. Wen Zhang;Wei Zhang;Hui Wang ; Bo Tang
Chemistry - A European Journal 2014 Volume 20( Issue 37) pp:11760-11767
Publication Date(Web):
DOI:10.1002/chem.201402999
Abstract
Fluorescence ratio imaging is currently being used to quantitatively detect biologically active molecules in biosystems; however, two excitations of most existing fluorescent ratiometric probes account for cumbersome operating conditions for imaging. Thus, a fluorescent ratiometric probe, 6-methoxyquinolinium–dansyl (MQ-DS), for Cl− with single excitation/dual maximum emission has been developed. MQ-DS can preferably localize into lysosomes and display excellent photostability. Upon excitation at a single wavelength, it responds precisely and instantaneously to changes in Cl− concentrations, and it can be conveniently utilized to implement real-time fluorescence ratio imaging to quantitatively track alterations in Cl− levels inside cells treated under various pH conditions, and also in zebrafish with acute wounds. The successful application of the new probe in bioimaging may greatly facilitate a complete understanding of the physiological functions of Cl−.
Co-reporter:Dr. Na Li;Wei Diao;Yaoyao Han;Dr. Wei Pan;Tingting Zhang ; Bo Tang
Chemistry - A European Journal 2014 Volume 20( Issue 50) pp:16488-16491
Publication Date(Web):
DOI:10.1002/chem.201404625
Abstract
Persistent luminescence nanoparticles (PLNPs) hold great promise for the detection and imaging of biomolecules. Herein, we have demonstrated a novel nanoprobe, based on the manganese dioxide (MnO2)-modified PLNPs, that can detect and image glutathione in living cells and in vivo. The persistent luminescence of the PLNPs can be efficiently quenched by the MnO2 nanosheets. In the presence of glutathione (GSH), MnO2 was reduced to Mn2+ and the luminescence of PLNPs can be restored. The persistent luminescence property can allow detection and imaging without external excitation and avoid the background noise originating from the in situ excitation. This strategy can offer a promising platform for detection and imaging of reactive species in living cells or in vivo.
Co-reporter:Wen Zhang ; Ping Li ; Fan Yang ; Xiufen Hu ; Chuanzhi Sun ; Wei Zhang ; Dezhan Chen
Journal of the American Chemical Society 2013 Volume 135(Issue 40) pp:14956-14959
Publication Date(Web):September 23, 2013
DOI:10.1021/ja408524j
Overgeneration of reactive oxygen species (ROS) is closely associated with cellular damage and diseases. As superoxide anion (O2•–) is the precursor of other ROS, exploring O2•– fluctuations in cells and in vivo is of great significance. To address this critical need, we have developed a novel reversible fluorescent probe with one-photon and two-photon fluorescence properties, which is well suited for monitoring O2•– fluxes selectively and dynamically. Imaging results substantiate dynamic and reversible fluorescence responses of this probe to intracellular O2•– under apoptotic stimuli. Moreover, this probe can conveniently visualize changes in O2•– concentration during reperfusion injury in hepatocytes, zebrafish, and mice, by means of one-photon or two-photon imaging according to depths of various samples. The present study provides a powerful fluorescent imaging tool for dynamic tracking of O2•– in live cells and in vivo.
Co-reporter:Na Li;Zhengze Yu;Wei Pan;Yaoyao Han;Tingting Zhang
Advanced Functional Materials 2013 Volume 23( Issue 18) pp:2255-2262
Publication Date(Web):
DOI:10.1002/adfm.201202564
Abstract
A near-infrared (NIR) light-triggered nanocarrier is developed for intracellular controlled release with good stability, high nuclease resistance, and good biocompatibility. The nanocarrier consists of a gold nanorod core and mesoporous silica shell, capped with reversible single-stranded DNA valves, which are manipulated by switching between the laser on/off states. Upon laser irradiation, the valves of the nanocarrier open and the cargo molecules can be released from the mesopores. When the NIR laser is turned off, the valves close and the nanocarrier stops releasing the cargo molecules. The release amount of the cargo molecules can be controlled precisely by adjusting the irradiation time and the laser on-off cycles. Confocal fluorescence imaging shows that the nanocarrier can be triggered by the laser irradiation and the controlled release can be accomplished in living cells. Moreover, the therapeutic effect toward cancer cells can also be regulated when the chemotherapeutic drug doxorubicin is loaded into the nanocarrier. This novel approach provides an ideal platform for drug delivery by a NIR light-activated mechanism with precise control of area, time, and especially dosage.
Co-reporter:Na Li;Zhengze Yu;Wei Pan;Yaoyao Han;Tingting Zhang
Advanced Functional Materials 2013 Volume 23( Issue 18) pp:
Publication Date(Web):
DOI:10.1002/adfm.201370087
Co-reporter:Xu Wang, Juan Sun, Weihong Zhang, Xiaoxu Ma, Jianzheng Lv and Bo Tang
Chemical Science 2013 vol. 4(Issue 6) pp:2551-2556
Publication Date(Web):05 Apr 2013
DOI:10.1039/C3SC50369K
We describe the design and synthesis of a cyanine-based near-infrared ratiometric fluorescent probe, HS–Cy, for H2S detection, which features rapid response, high sensitivity, and mitochondria targeting. After a rapid quenching at 780 nm by initial nucleophilic addition on the aldehyde group, HS–Cy experienced a polymethine π-electron conjugation modulation triggered by a second nucleophilic addition on the ester, releasing the cyanine fluorophore which underwent tautomerism from enol form to ketone form. Therefore, gradual emergence of a new peak at 625 nm was observed, constructing a ratiometric signal for H2S with a detection limit of 5.0–10 nM, which is the most sensitive among the reported H2S-sensing fluorescent probes. HS–Cy was proven to selectively locate into mitochondria with faster trapping kinetics towards H2S. Based on this, the endogenously generated H2S in human A549 cells was ratiometrically detected and imaged by HS–Cy.
Co-reporter:Kehua Xu, Mingming Qiang, Wen Gao, Ruixian Su, Na Li, Yan Gao, Yanxia Xie, Fanpeng Kong and Bo Tang
Chemical Science 2013 vol. 4(Issue 3) pp:1079-1086
Publication Date(Web):14 Dec 2012
DOI:10.1039/C2SC22076H
Alterations of cellular redox status are closely associated with physiological and pathological processes. Glutathione (GSH) and H2O2 should be the most representative redox couple in living cells. However, up to now, there is no way to reversibly detect GSH/H2O2. In this report, a near-infrared (NIR) fluorescent probe (Cy-O-Eb) for monitoring the changes of GSH/H2O2 levels in vivo was developed based on switching on–off a five-membered ring involved in ebselen. This probe could reversibly respond to GSH and H2O2 with high selectivity, sensitivity and mitochondrial targeting. It was successfully used to monitor the changes of redox status during apoptosis and the H2O2 changes at the wound margin in zebrafish larvae. Thus, the probe would provide an ideal tool for monitoring redox status changes and studying molecular events involved in redox regulation.
Co-reporter:Guan-wei Cui, Wei-liang Wang, Ming-yue Ma, Ming Zhang, Xin-yuan Xia, Feng-yun Han, Xi-feng Shi, Ying-qiang Zhao, Yu-Bin Dong and Bo Tang
Chemical Communications 2013 vol. 49(Issue 57) pp:6415-6417
Publication Date(Web):03 Jun 2013
DOI:10.1039/C3CC42500B
The rational design of carbonaceous hybrid nanostructures is very important for obtaining high photoactivity. TiO2 particles strewn with an optimal quantity of carbon nanodots have a much higher photoactivity than that of TiO2 covered with a carbon layer, showing the importance of carbon morphology in the photocatalysis of carbonaceous hybrid nanostructures.
Co-reporter:Fanpeng Kong, Renpu Liu, Ranran Chu, Xu Wang, Kehua Xu and Bo Tang
Chemical Communications 2013 vol. 49(Issue 80) pp:9176-9178
Publication Date(Web):07 Aug 2013
DOI:10.1039/C3CC45519J
A near-infrared fluorescent probe (Cy–O–CHO) for the detection of endogenous Cys/Hcy in living cells was designed and synthesized. Cy–O–CHO exhibited high sensitivity and good selectivity to Cys/Hcy under physiological conditions with a detection limit of 7.9 nM for Cys.
Co-reporter:Kehua Xu, Feng Wang, Xiaohong Pan, Renpu Liu, Jing Ma, Fanpeng Kong and Bo Tang
Chemical Communications 2013 vol. 49(Issue 25) pp:2554-2556
Publication Date(Web):11 Feb 2013
DOI:10.1039/C3CC38980D
A highly selective and sensitive near-infrared (NIR) fluorescence probe (Cy-NO2) for imaging nitroreductase was developed and was successfully applied to investigating the relationship between epithelial–mesenchymal transitions (EMTs) in tumour progression and intracellular hypoxic level.
Co-reporter:Shufeng Liu, Chunfeng Wang, Chengxin Zhang, Ying Wang, and Bo Tang
Analytical Chemistry 2013 Volume 85(Issue 4) pp:2282
Publication Date(Web):January 16, 2013
DOI:10.1021/ac303225p
In this work, a very simple, label-free, isothermal, and ultrasensitive electrochemical DNA biosensor has been developed on the basis of an autocatalytic and exonuclease III (Exo III)-assisted target recycling amplification strategy. A duplex DNA probe constructed by the hybridization of a quadruplex-forming oligomer with a molecular beacon is ingeniously designed and assembled on the electrode as recognition element. Upon sensing of the analyte nucleic acid, the strand of molecular beacon in the duplex DNA probe could be stepwise removed by Exo III accompanied by the releasing of target DNA and autonomous generation of new secondary target DNA fragment for the successive hybridization and cleavage process. Simultaneously, numerous quadruplex-forming oligomers are liberated and folded into G-quadruplex–hemin complexes with the help of K+ and hemin on the electrode surface to give a remarkable electrochemical response. Because of this autocatalytic target recycling amplification and the specifically catalyzed formation of G-quadruplex–hemin complexes, this newly designed protocol provides an ultrasensitive electrochemical detection of DNA down to the 10 fM level, can discriminate mismatched DNA from perfectly matched target DNA, and holds a great potential for early diagnosis in gene-related diseases. It further could be developed as a universal protocol for the detection of various DNA sequences and may be extended for the detection of aptamer-binding molecules.
Co-reporter:Haiyun Liu, Lu Li, Lili Duan, Xu Wang, Yanxia Xie, Lili Tong, Qian Wang, and Bo Tang
Analytical Chemistry 2013 Volume 85(Issue 16) pp:7941
Publication Date(Web):July 16, 2013
DOI:10.1021/ac401715k
In this paper, a padlock probe-based exponential rolling circle amplification (P-ERCA) assay is developed for highly specific and sensitive detection of microRNA (miRNA). The padlock probe is composed of a hybridization sequence to miRNA and a nicking site for nicking endonuclease. Using the miRNA as a template, specific ligation to the padlock probe and linear rolling circle reaction (LRCA) are achieved under isothermal conditions. After multiple nicking reactions, many copies of short DNA products are successively produced and then used as triggers in next circle amplification. Thus, a small amount of miRNAs are converted to a large number of triggers to initiate the rolling circle amplification reaction, and circular exponential signal amplification is achieved. This padlock probe-based exponential rolling circle amplification assay exhibits a remarkable sensitivity of 0.24 zmol using optimized sequences of the padlock probe. The target-dependent circularization of the padlock probe and the ligation reaction could improve the specificity effectively, leading to single–nucleotide difference discrimination between miRNA family members. The miRNA analysis in human lung cells was performed with this method. The result indicates this highly sensitive P-ERCA strategy will become a promising miRNA quantification method in early clinical diagnostics.
Co-reporter:Ping Li, Wen Zhang, Kexiang Li, Xiao Liu, Haibin Xiao, Wei Zhang, and Bo Tang
Analytical Chemistry 2013 Volume 85(Issue 20) pp:9877
Publication Date(Web):September 12, 2013
DOI:10.1021/ac402409m
A newly synthesized reaction-based two-photon (TP) fluorescence imaging probe, 9-butyltriphenylphosphoniumacylamino-2,7-dibenzothiazolineflurene (MF-DBZH), composed of a superoxide anion (O2•–) responsive group and a mitochondria-targeted site, has been shown to have high selectivity toward mitochondrial O2•– fluxes. The fluorescence intensity of MF-DBZH responds proportionally to changes in O2•– concentrations. Moreover, MF-DBZH was proved to be insensitive toward pH changes and has high photostability. Favorable features of this probe also include convenient cell loading, easy staining of both cells and small animals, and excellent biocompibility. Most importantly, MF-DBZH gives reliable TP fluorescent signal to changes of O2•– levels in vivo.
Co-reporter:Lu Li, Feifei Gao, Jian Ye, Zhenzhen Chen, Qingling Li, Wen Gao, Lifei Ji, Ruirui Zhang, and Bo Tang
Analytical Chemistry 2013 Volume 85(Issue 20) pp:9721
Publication Date(Web):September 16, 2013
DOI:10.1021/ac4021227
In this paper, we have developed a biofriendly and high sensitive apo-GOx (inactive form of glucose oxidase)-modified gold nanoprobe for quantitative analysis of glucose and imaging of glucose consumption in living cells. This detection system is based on fluorescence resonance energy transfer between apo-GOx modified AuNPs (Au nanoparticles) and dextran-FITC (dextran labeled with fluorescein isothiocyanate). Once glucose is present, quenched fluorescence of FITC recovers due to the higher affinity of apo-GOx for glucose over dextran. The nanoprobe shows excellent selectivity toward glucose over other monosaccharides and most biological species present in living cells. A detection limit as low as 5 nM demonstrates the high sensitivity of the nanoprobe. Introduction of apo-GOx, instead of GOx, can avoid the consumption of O2 and production of H2O2 during the interaction with glucose, which may exert effects on normal physiological events in living cells and even lead to cellular damage. Due to the low toxicity of this detection system and reliable cellular uptake ability of AuNPs, imaging of intracellular glucose consumption was successfully realized in cancer cells.
Co-reporter:Wei Pan, Tingting Zhang, Huijun Yang, Wei Diao, Na Li, and Bo Tang
Analytical Chemistry 2013 Volume 85(Issue 21) pp:10581
Publication Date(Web):October 2, 2013
DOI:10.1021/ac402700s
Simultaneous detection and imaging of multiple intracellular biomarkers hold great promise for early cancer detection. Here, we introduce a four-color nanoprobe that can simultaneously detect and image four types of mRNAs in living cells. The nanoprobe composed of gold nanoparticles functionalized with a dense shell of molecular beacons, which can identify multiple intracellular mRNA transcripts. It shows rapid response, high specificity, nuclease stability, and good biocompatibility. Intracellular experiments indicate that the nanoprobe could effectively distinguish cancer cells from their normal cells, even some mRNAs are overexpressed in normal cells. Moreover, it can identify the changes of the expression levels of mRNA in living cells. The current strategy could provide more-accurate information for early cancer detection and availably avoid false positive results.
Co-reporter:Wei Pan, Huijun Yang, Tingting Zhang, Yanhua Li, Na Li, and Bo Tang
Analytical Chemistry 2013 Volume 85(Issue 14) pp:6930
Publication Date(Web):June 17, 2013
DOI:10.1021/ac401405n
Developing efficient methods for targeting cancer cells and encapsulating drugs coupled with activated release holds enormous potential for cancer cell imaging and therapy. Herein, a novel dual-targeted nanocarrier was developed on the basis of gold nanoparticles modified with a dense shell of synthetic oligonucleotides. The folic acid functionalized single-stranded DNA was designed to target the folate receptor on the cancer cell surface, and the molecular beacon was employed as drug carrier for activated release associated with intracellular tumor mRNA. Intracellular experiments indicated that the dual-targeted nanocarrier could be preferentially internalized into cancer cells due to the folate receptor targeting and release Doxorubicin (Dox) selectively in cancer cells because of the activated release with intracellular mRNA. The nanocarrier could reduce the dosage and greatly improve the therapeutic effect of drugs in cancer cells. Moreover, the nanocarrier can identify the changes of the express level of tumor mRNA and release Dox in a controlled manner in cancer cells, which would be beneficial for cancer therapy.
Co-reporter:Feng Li, Limin Yang, Mingqin Chen, Peng Li and Bo Tang
Analyst 2013 vol. 138(Issue 2) pp:461-466
Publication Date(Web):25 Oct 2012
DOI:10.1039/C2AN36227A
A novel strategy for selective and sensitive amperometric detection of lead ion (Pb2+) was proposed based on target-induced strand release. The underlying gold electrode was pre-modified with dendritic gold nanoparticles by direct electrodeposition to afford increased electrode surface area for immobilization of thiol group-containing capture DNA molecules. The hybridization of the capture DNA molecules with Pb2+-specific aptamer molecules to form a DNA duplex, into which methylene blue was intercalated, induced measurable electrochemical signal. Upon addition of Pb2+, it could specifically bind to its aptamer to form Pb2+-stablized G-quadruplex and induce the aptamer strand to release from the electrode surface into solution, accompanied by the release of intercalated MB responsible for significant signal reduction. The fabricated biosensor showed a linear response to the logarithm of Pb2+ concentration over the range of 1.0 × 10−10 M to 1.0 × 10−7 M with a detection limit of 7.5 × 10−11 M. In addition, this strategy afforded an exquisite selectivity for Pb2+ against other metal ions. The excellent sensitivity and selectivity show good potential for Pb2+ detection in real environmental samples.
Co-reporter:Li-li Tong, Lu Li, Zhenzhen Chen, Qian Wang, Bo Tang
Biosensors and Bioelectronics 2013 Volume 49() pp:420-425
Publication Date(Web):15 November 2013
DOI:10.1016/j.bios.2013.05.051
•A lable-free and turn-on fluorescence sensor for thiols is proposed.•ThT/G-4 as a new key detection component can generate stable fluorescence.•The sensing relies on structure-switch of DNA controlled by Hg2+ and ThT.•The system is simple and fast in operation with the help of premixing strategy.In this work, a new, label-free, turn-on fluorescent sensor for biothiols detection based on ThT direct inducing conformation-specific G-quadruplex is developed. The sensing approach is based on a conformational switch of oligonucleotide controlled by Hg2+ and a commercially available water-soluble fluorescent dye, Thioflavin T (ThT). A noticeable fluorescence light-up in ThT on binding to the G-quadruplex grants the sensor excellent sensitivity. The specific quadruplex conformation induced directly by ThT and pronounced structural selectivity of ThT for G-quadruplexes could generate more stable luminescence and make sure high specificity in complex biological samples. The present assay allows for the selective determination of cysteine and glutathione in the range of 2.0×10−8–2.5×10−6 M and 3.0×10−8–2.0×10−6 M with a detection limit of 8.4 nM and 13.9 nM respectively. The diagnostic capability and potential in practical applications of this method have been demonstrated by detecting biothiols in human blood serum.
Co-reporter:Guan-wei Cui, Xi-Feng Shi, Na Li, Chongbin Wang, Yu-Bin Dong, Xu Wang and Bo Tang
Journal of Materials Chemistry A 2012 vol. 22(Issue 24) pp:11915-11918
Publication Date(Web):01 May 2012
DOI:10.1039/C2JM31549A
A novel photocatalyst, TiO2 nanotubes with the confinement of the electron donor and acceptor at the inner and outer surface, respectively, was fabricated by a universal method. The as-designed nanostructure afforded a void space separation state of electron donors and acceptors, which remarkably enhanced the photoinduced charge separation, resulting in the enhancement of the catalytic activity for the photooxidation of olefins with O2.
Co-reporter:Jie Ding, Xia Kong, Jing Yao, Jian Wang, Xiaoguang Cheng, Bo Tang and Zhiwei He
Journal of Materials Chemistry A 2012 vol. 22(Issue 37) pp:19926-19931
Publication Date(Web):07 Aug 2012
DOI:10.1039/C2JM32271D
(−)-Epigallocatechin-3-gallate (EGCG) is an effective anticancer drug for a variety of cancer cell lines, but it is unstable with a half-life of 30 minutes to 2 hours under different culture conditions for cell apoptosis; EGCG dimers, hydrogen peroxide (H2O2) and other oxidative products are formed. Herein, we report that a multiple core–shell functionalized colloidal mesoporous silica nanoparticle system (CMS) resulted in the electrostatic attraction of EGCG to the surface and pores, alleviating the interaction of free radicals which produced dimers or other polymers. Based on the results of MTT assay, cell cycle analysis and western blot, the loading of EGCG into the CMS increased the anticancer ability of EGCG compared to that of free EGCG being used to treat HeLa cells in the absence of CMS. In addition, fluorescein isothiocyanate (FITC) was entrapped in the core of CMS, which allowed the CMS to simultaneously denote the position of EGCG in cells. These results demonstrate that it is possible to use the CMS platform as a promoter to improve the anticancer ability of the unstable chemotherapeutic agent.
Co-reporter:Kehua Xu, Shuxia Sun, Jing Li, Lu Li, Mingming Qiang and Bo Tang
Chemical Communications 2012 vol. 48(Issue 5) pp:684-686
Publication Date(Web):01 Dec 2011
DOI:10.1039/C1CC15844A
A near-infrared fluorescent probe (Trp-Cy) for endogenous ozone is presented, which exhibited a large stokes shift about 140 nm and a rapid fluorescence response to ozone with high selectivity and sensitivity.
Co-reporter:Feng Li, Peng Li, Limin Yang and Bo Tang
Chemical Communications 2012 vol. 48(Issue 100) pp:12192-12194
Publication Date(Web):02 Nov 2012
DOI:10.1039/C2CC36404B
A new strategy for determining the RNA endonuclease activity of mammalian argonaute2 (Ago2) protein has been developed, which combines the unique cleavage function of Ago2 protein with an RNA molecular beacon (RMB). Through the fluorescence restoration of the RMB, simple and sensitive detection of Ago2 is achieved.
Co-reporter:Na Li, Hui Wang, Mei Xue, Chenyang Chang, Zhenzhen Chen, Linhai Zhuo and Bo Tang
Chemical Communications 2012 vol. 48(Issue 19) pp:2507-2509
Publication Date(Web):05 Jan 2012
DOI:10.1039/C2CC16376D
A novel fluorescent nanoprobe with high sensitivity and selectivity for detection and imaging of the superoxide anion radical () in living cells was designed and synthesized by a simple self-assembly method based on 2-chloro-1,3-dibenzothiazoline-cyclohexene (DBZTC) and Ag@SiO2 core–shell nanoparticles.
Co-reporter:Feng Li, Yan Feng, Can Zhao, Peng Li and Bo Tang
Chemical Communications 2012 vol. 48(Issue 1) pp:127-129
Publication Date(Web):03 Nov 2011
DOI:10.1039/C1CC15694B
A sensitive and selective fluorescent sensing platform for bleomycin (BLM) was developed based on BLM-induced DNA strand scission and the difference in affinity of graphene oxide for single-stranded DNA containing different numbers of bases in length.
Co-reporter:Zhenzhen Chen, Qingling Li, Qianqian Sun, Hao Chen, Xu Wang, Na Li, Miao Yin, Yanxia Xie, Hongmin Li, and Bo Tang
Analytical Chemistry 2012 Volume 84(Issue 11) pp:4687
Publication Date(Web):May 2, 2012
DOI:10.1021/ac300255n
Determination of intracellular bioactive species will afford beneficial information related to cell metabolism, signal transduction, cell function, and disease treatment. In this study, the first application of a microchip electrophoresis–laser-induced fluorescence (MCE–LIF) method for concurrent determination of reactive oxygen species (ROS) and reactive nitrogen species (RNS), i.e., superoxide (O2–•) and nitric oxide (NO) in mitochondria, was developed using fluorescent probes 2-chloro-1,3-dibenzothiazolinecyclohexene (DBZTC) and 3-amino,4-aminomethyl-2′,7′-difluorescein (DAF-FM), respectively. Potential interference of intracellular dehydroascorbic acid (DHA) and ascorbic acid (AA) for NO detection with DAF-FM was eliminated through oxidation of AA with the addition of ascorbate oxidase, followed by subsequent MCE separation. Fluorescent products of O2–• and NO, DBZTC oxide (DBO), and DAF-FM triazole (DAF-FMT) showed excellent baseline separation within 1 min with a running buffer of 40 mM Tris solution (pH 7.4) and a separating electric field of 500 V/cm. The levels of DBO and DAF-FMT in mitochondria isolated from normal HepG2 cells and PC12 cells were evaluated using this method. Furthermore, the changes of DBO and DAF-FMT levels in mitochondria isolated from apoptotic HepG2 cells and PC12 cells could also be detected. The current approach was proved to be simple, fast, reproducible, and efficient. Measurement of the two species with the method will be beneficial to understand ROS/RNS distinctive functions. In addition, it will provide new insights into the role that both species play in biological systems.
Co-reporter:Shiguo Wang, Na Li, Wei Pan, Bo Tang
TrAC Trends in Analytical Chemistry 2012 Volume 39() pp:3-37
Publication Date(Web):October 2012
DOI:10.1016/j.trac.2012.07.010
We summarize recent progress in imaging intracellular small-molecule reactive species (ISMRS) by functional probes. In molecular imaging, functional fluorescent and luminescent probes (e.g., ratiometric, targetable fluorescent, reversible fluorescent, and multi-functional) and corresponding nanoprobes have great potential for investigating ISMRS-mediated cell-signal transduction. We describe design strategies for the development of functional probes. Future research on ISMRS will benefit from recent advances in the development of new functional probes for selective detection of ISMRS.Highlights► Intracellular small-molecule reactive species are important signaling molecules. ► Functional probes for imaging Intracellular small-molecule reactive species (ISMRS). ► We discuss classification and strategies of developing functional probes. ► We review nanoprobes for multi-functional detection and therapeutic application.
Co-reporter:Wen Gao, Lifei Ji, Lu Li, Guanwei Cui, Kehua Xu, Ping Li, Bo Tang
Biomaterials 2012 Volume 33(Issue 14) pp:3710-3718
Publication Date(Web):May 2012
DOI:10.1016/j.biomaterials.2012.01.047
We demonstrate bifunctional combined Au-Fe2O3 nanoparticles (NPs) for selectively induction of apoptosis in cancer cells and real-time imaging. The as-prepared Au-Fe2O3 NPs combine the merits of both Au and γ-Fe2O3 NPs, maintaining excellent fluorescence quenching property and catalytic activity. Conjugated with αⅤβ3 integrin-targeting peptide (RGD) and fluorescein isothiocyanate (FITC)-labeled capsase-3 recognition sequence (DEVD) on the Au surface, the resulting RGD/FITC–DEVD–Au-Fe2O3 NPs bind preferentially to integrin αⅤβ3-rich human liver cancer cells (HepG2), sequentially initiate catalytic formation of hydroxyl radicals (OH) and enable the real-time monitoring ofOH-induced caspase-3-dependent apoptosis in these cancer cells. Furthermore, the catalytic activity of RGD/FITC–DEVD–Au-Fe2O3 NPs is much higher than that of individual γ-Fe2O3 NPs due to the polarization effect at the Au-Fe2O3 interface. Such bifunctional Au-Fe2O3 NPs exhibit simultaneous targeting, therapeutic and imaging functions and are therefore promising for future therapeutic applications in cancer.
Co-reporter:Dr. Na Li;Chenyang Chang;Wei Pan ; Bo Tang
Angewandte Chemie International Edition 2012 Volume 51( Issue 30) pp:
Publication Date(Web):
DOI:10.1002/anie.201204826
Co-reporter:Dr. Na Li;Chenyang Chang;Wei Pan ; Bo Tang
Angewandte Chemie International Edition 2012 Volume 51( Issue 30) pp:7426-7430
Publication Date(Web):
DOI:10.1002/anie.201203767
Co-reporter:Dr. Na Li;Chenyang Chang;Wei Pan ; Bo Tang
Angewandte Chemie 2012 Volume 124( Issue 30) pp:7544-7548
Publication Date(Web):
DOI:10.1002/ange.201203767
Co-reporter:Dr. Na Li;Chenyang Chang;Wei Pan ; Bo Tang
Angewandte Chemie 2012 Volume 124( Issue 30) pp:
Publication Date(Web):
DOI:10.1002/ange.201204826
Co-reporter:Mei Xue, Xu Wang, Lili Duan, Wen Gao, Lifei Ji, Bo Tang
Biosensors and Bioelectronics 2012 Volume 36(Issue 1) pp:168-173
Publication Date(Web):June–July 2012
DOI:10.1016/j.bios.2012.04.007
A new nanoprobe was designed for the fluorescence imaging of fluoride anion (F−) in living cells with high sensitivity and selectivity. The design is based on the fluorescence resonance energy transfer (FRET) between CdTe quantum dots (CdTe QDs) and gold nanoparticles (AuNPs) through the formation of cyclic esters between phenylborinic acid and diol. In the presence of F−, the boronate ester, a “hard acid”, strongly reacts with F−, a “hard base”. Therefore, the boronate ester is converted to trifluoro borate, which causes the breakage of the linkage and disassembles CdTe QDs from AuNPs, resulting in the fluorescence recovery of the quenched CdTe QDs. The interaction mechanism was investigated by 19FNMR on a model that was constructed by a small molecule and F−. Quantum chemical calculations also testify the reactivity of boronate ester to F− and the sensing mechanism. Experimental results show that the increase in fluorescence intensity is proportional to the concentration of F− in the range of 5.0–45 μM. The detection limit and the relative standard deviation were 50 nM and 2.6%, respectively. Fluorescence imaging of F− in macrophages cells indicates good cell membrane penetration ability and low cytotoxicity of the nanoprobe, providing a viable alternative to detection of F− in biological or environmental samples.Highlights► A new nanoprobe for F− was designed between CdTe QDs and gold nanoparticles. ► High affinity of F− towards boron converts boronate ester into trifluoro borate. ► Disassembly of the nanoprobe results in the fluorescence recovery of CdTe QDs. ► Nanoprobe shows good cell membrane penetration ability and low cytotoxicity. ► Fluorescence imaging of F− in macrophages cells was achieved by the nanoprobe.
Co-reporter:Ping Li, Hui Zhou, Bo Tang
Journal of Photochemistry and Photobiology A: Chemistry 2012 Volume 249() pp:36-40
Publication Date(Web):1 December 2012
DOI:10.1016/j.jphotochem.2012.08.020
Co-reporter:Dr. Xu Wang;Yanqing Xia;Yuanyuan Liu;Wenxue Qi;Qianqian Sun;Qian Zhao ; Bo Tang
Chemistry - A European Journal 2012 Volume 18( Issue 23) pp:7189-7195
Publication Date(Web):
DOI:10.1002/chem.201200227
Abstract
Although considerable effort has been devoted to the design of various nanoprobes for the fluorescent detection of multiple biomarkers in a single assay, they often suffer from emission-overlapping, owing to small Stokes shifts and wide emission spectra, which results in cross-talk and inaccurate quantification. Herein, we report the design and synthesis of a new nanoprobe for multienzyme detection with completely resolved emission peaks under single-wavelength excitation. The probe was assembled by attaching a cleavable peptide spacer, which was comprised from a matrix metalloproteinase-2 (MMP-2) substrate and a MMP-7 substrate, onto the surface of gold nanoparticles (AuNPs) through cysteine residues. A lanthanide complex, BCTOT-EuIII (BCTOT=1,10-bis(5′-chlorosulfo-thiophene-2′-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone), and 7-amino-4-methylcoumarin (AMC) were attached to the N terminus and the C terminus of the peptide, respectively. In the presence of one or both targeting enzymes, the substrate was cleaved and fluorescence resonance energy transfer (FRET) between the dyes and AuNPs was prohibited, thereby resulting in the dramatic fluorescence emission of dyes. Importantly, there was no emission cross-talk between the two dyes, thereby ensuring accurate detection of each enzyme. Based on this, the simultaneous fluorescence image of MMP-2 and MMP-7 was accomplished in living cells under single wavelength excitation. The apparent differences in the fluorescence imaging indicated distinct differences between the expression levels of MMPs between the human normal liver cells and the human hepatoma cells.
Co-reporter:Mei Xue, Xu Wang, Hui Wang, Dezhan Chen and Bo Tang
Chemical Communications 2011 vol. 47(Issue 17) pp:4986-4988
Publication Date(Web):22 Mar 2011
DOI:10.1039/C0CC05389A
Specific hydrogen bond breakage by fluoride anions was observed in a simple FRET system formed by thioglycolic acid modified CdTe quantum dots and citrate-capped gold nanoparticles.
Co-reporter:Feng Li, Yan Feng, Can Zhao and Bo Tang
Chemical Communications 2011 vol. 47(Issue 43) pp:11909-11911
Publication Date(Web):05 Oct 2011
DOI:10.1039/C1CC15023E
A sensitive and selective amperometric sensing platform for lead (Pb2+) was developed based on a Pb2+-induced G-rich DNA conformational switch from a random-coil to G-quadruplex (G4) with crystal violet as the G4-binding indicator.
Co-reporter:Kehua Xu, Huachao Chen, Jiangwei Tian, Baiyu Ding, Yanxia Xie, Mingming Qiang and Bo Tang
Chemical Communications 2011 vol. 47(Issue 33) pp:9468-9470
Publication Date(Web):22 Jul 2011
DOI:10.1039/C1CC12994E
BzSe-Cy is a small-molecule fluorescent probe containing Se, which can respond reversibly to changes in ONOO− or reduced ascorbate and exhibit high sensitivity and selectivity for ONOO−.
Co-reporter:Ping Li, Xia Duan, Zhenzhen Chen, Ying Liu, Ting Xie, Libo Fang, Xiaorui Li, Miao Yin and Bo Tang
Chemical Communications 2011 vol. 47(Issue 27) pp:7755-7757
Publication Date(Web):27 May 2011
DOI:10.1039/C1CC11885D
The first near-infrared fluorescent probe was developed toward Cu2+. Based on the photo-induced electron transfer (PET) mechanism, the probe exhibited weak fluorescence. Upon the addition of Cu2+, it fluoresced strongly. The probe offered this unique capability, and was successfully applied to living cells, tissues and in vivo to visualize Cu2+.
Co-reporter:Guangming Qiao, Linhai Zhuo, Yuan Gao, Lijuan Yu, Na Li and Bo Tang
Chemical Communications 2011 vol. 47(Issue 26) pp:7458-7460
Publication Date(Web):17 May 2011
DOI:10.1039/C1CC11490E
We demonstrate a tumor mRNA-dependent drug carrier for controlled release of doxorubicin (Dox) and intracellular imaging based on gold nanoparticle–molecular beacon. Fluorescent Dox is released effectively and induces apoptosis in breast cancer cells but not in normal cells. Significantly, the release of Dox is correlated positively with the quantities of tumor mRNA, which is according to various stages of tumor progression, and so can decrease effectively side effects of Dox.
Co-reporter:Feng Li, Yan Feng, Shufeng Liu and Bo Tang
Chemical Communications 2011 vol. 47(Issue 22) pp:6347-6349
Publication Date(Web):06 May 2011
DOI:10.1039/C1CC11858G
The cleavage activity of a nicking endonuclease towards metal-ion-mediated duplex-like DNA can be triggered by the corresponding metal ions, which was demonstrated with mercuric(II) ion as a model via a simple electrochemical protocol.
Co-reporter:Yuan Gao, Guangming Qiao, Linhai Zhuo, Na Li, Ying Liu and Bo Tang
Chemical Communications 2011 vol. 47(Issue 18) pp:5316-5318
Publication Date(Web):31 Mar 2011
DOI:10.1039/C1CC10557D
A bi-photosensitizer molecular beacon (bi-PS MB) is assembled by coupling two PS molecules, respectively, onto the opposite ends of a single MB. The MB can be triggered by a tumor marker-survivin mRNA. Fluorescence and cytotoxic 1O2 generation occur effectively in breast cancer cells, but not in normal cells. Compared with a single-PS MB, a bi-PS MB exhibits much-enhanced properties in the signal-to-background ratio and 1O2 generation simultaneously.
Co-reporter:Kehua Xu, Lulu Wang, Mingming Qiang, Liyong Wang, Ping Li and Bo Tang
Chemical Communications 2011 vol. 47(Issue 26) pp:7386-7388
Publication Date(Web):31 May 2011
DOI:10.1039/C1CC12473K
A selective near-infrared fluorescent probe (His–Cy), which features a fast response to 1O2 with high sensitivity and selectivity, was designed, synthesized and applied to bioimaging.
Co-reporter:Ping Li, Ying Liu, Xu Wang and Bo Tang
Analyst 2011 vol. 136(Issue 21) pp:4520-4525
Publication Date(Web):16 Sep 2011
DOI:10.1039/C1AN15271H
A new self-assembly nanoprobe, mercaptoethylamine-modified-gold nanoparticles–Lysine-bridged-bis(β-cyclodextrins)–fluorescein (MGNPs–Lys-bis(β-CDs)–FL), based on fluorescence resonance energy transfer (FRET) was developed for determination of trypsin firstly in biological systems. With the Lys-bis(β-CDs)–FL complex as an energy donor and mercaptoethylamine (MEA)-modified gold nanoparticles (MGNPs) as an energy acceptor, the two parts assemble an efficient FRET nanoprobe through an amide bond. Trypsin is specific for the hydrolysis of amide linkages of lysine. Therefore, in the presence of trypsin, the nanoprobe is cleaved by trypsin on the binding sites of amide with good specificity and sensitivity, resulting in the fluorescence recovery of the quenched FL. The nanoprobe has good biological applicability and provides a potential assay for further clinical research of trypsin in biosystems.
Co-reporter:Xia Duan, Puming Li, Ping Li, Ting Xie, Fabiao Yu, Bo Tang
Dyes and Pigments 2011 Volume 89(Issue 3) pp:217-222
Publication Date(Web):June 2011
DOI:10.1016/j.dyepig.2010.03.007
Two novel BODIPY dyes were synthesized, and their fluorescence characteristics studied in different solvents. Both dyes were extremely sensitive to solvent polarity. Their fluorescence intensities were very low in DMSO but increased more than 80 times in chloroform; similar behaviour was found in fluorescence quantum yield, which was enhanced ∼60-fold. Both dyes displayed fluorescence enhancement with bovine serum albumin, which illustrated that the two probes were very sensitive to polarity change and, therefore, may be valuable as microenvironment-sensitive probes in biochemical research.
Co-reporter:Kehua Xu, Fen Liu, Jing Ma and Bo Tang
Analyst 2011 vol. 136(Issue 6) pp:1199-1203
Publication Date(Web):06 Jan 2011
DOI:10.1039/C0AN00576B
A novel fluorescent probe (C60-FL) was designed and synthesized for the direct determination of trypsin, based on photo-induced electron transfer (PET). The probe consists of two functional moieties: fluorescein which performs as a fluorophore and an electron donor, and fullerene (C60) which acts as an electron acceptor and trypsin substrate analogue. In the presence of trypsin, the probe exhibited fluorescence increase due to the inhibition of electron transfer by the combination of C60-FL with trypsin. The response of the probe to trypsin was direct and rapid. Experimental results showed that the increase in fluorescence intensity is proportional to the concentration of trypsin within the range of 4.40 × 10−7 to 7.04 × 10−5 g mL−1 under the optimized experimental conditions. The detection limit of the proposed method was 40 ng mL−1. The method had high selectivity for trypsin over other enzymes and proteins, such as lipase, α-amylase, bovine serum albumin, zinc metallothionein, glutathione reductase, thioredoxin and α-chymotrypsin etc. The remarkable properties of C60-FL help to extend the development of fluorescent probes for investigating enzymes in a biological context.
Co-reporter:Dongmei Chen, Zhenzhen Chen, Kehua Xu, and Bo Tang
Journal of Agricultural and Food Chemistry 2011 Volume 59(Issue 9) pp:4424-4428
Publication Date(Web):April 11, 2011
DOI:10.1021/jf200343b
The supramolecular interaction of disulfide linked β-cyclodextrin (β-CD) dimer and dimethomorph has been studied by spectrofluorimetry. Based on the significant enhancement of the fluorescence intensity of dimethomorph, a new spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of dimethomorph in bulk aqueous in the presence of the disulfide linked β-CD dimer. The inclusion complexation behavior of β-CD dimer with dimethomorph was studied in a KH2PO4–H3PO4 buffer solution of pH 3.86 at room temperature. The apparent association constant of the complex was 2.25 × 104 L/mol. The linear range was 12–7500 ng/mL with the detection limit 3.70 ng/mL, and the limit of quantification was 12.4 ng/mL. The proposed method had been successfully applied to the determination of dimethomorph residues in vegetables with recoveries of 89.0–115%.
Co-reporter:Jiechao Ge, Jiangwei Tian, Linhai Zhuo, Huachao Chen, Bo Tang
Solid State Sciences 2011 Volume 13(Issue 8) pp:1554-1559
Publication Date(Web):August 2011
DOI:10.1016/j.solidstatesciences.2011.05.021
A facile hydrothermal approach based on n-nonyl alcohol mediated process has been developed to synthesize self-assembled Fe3O4 hierarchical nanostructures. The as-synthesized hierarchical nanostructured Fe3O4 could be easily transformed to γ-Fe2O3 and α-Fe2O3 without changing its original morphology by calcination in air. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were performed to investigate the evolution process of Fe3O4 hierarchical nanostructures. The growth mechanism of the as-prepared Fe3O4 nanostructure and the subsequently hierarchical nanostructures are suggested. The as-obtained iron oxide nanomaterials were used as adsorbent in water treatment, and were found an excellent ability to remove organic pollutants such as Orange II in waste water.Highlights► Fe3O4 hierarchical nanostructures have been prepared via a facile hydrothermal method. ► The as-synthesized Fe3O4 could be easily transformed to γ-Fe2O3 and α-Fe2O3 with the same hierarchical nanostructures. ► The as-obtained iron oxide nanomaterials have an excellent ability to remove organic pollutants.
Co-reporter:Feng Li, Yan Feng, Can Zhao, Bo Tang
Biosensors and Bioelectronics 2011 Volume 26(Issue 11) pp:4628-4631
Publication Date(Web):15 July 2011
DOI:10.1016/j.bios.2011.05.015
A simple colorimetric sensing platform for trace bleomycin (BLM) was proposed with the unmodified gold nanoparticles (AuNPs) as the sensing element. BLM has multiple N-donor functionality and exhibited strong coordination effect on AuNPs, which made it possible for the occurrence of ligand exchange of BLM with the weakly surface-bound citrate ions on AuNPs. Meanwhile, the positively charged BLM molecules further neutralized the surface charge, leading to increased van der Waals attractive force among AuNPs for rapid aggregation. This was reflected by the obvious color change from wine red to blue and rapid aggregation kinetics within 7.5 min. The BLM sensing based on unmodified AuNPs can be seen with the naked eye and monitored by UV–vis extinction spectra. The linear range of the colorimetric sensor for BLM was from 2 to 150 nM. The as-established colorimetric strategy opened a new avenue for trace BLM determination.
Co-reporter:Kehua Xu, Huachao Chen, Huixia Wang, Jiangwei Tian, Jing Li, Qingling Li, Na Li, Bo Tang
Biosensors and Bioelectronics 2011 Volume 26(Issue 11) pp:4632-4636
Publication Date(Web):15 July 2011
DOI:10.1016/j.bios.2011.05.020
A new fluorescent nanoprobe, 4-amino-2,2,6,6-tetramethylpiperidine oxide (AT)-functionalized CdTe quantum dots (QDs–AT), was synthesized, for selective detection of nonprotein thiols based on electron transfer (ET). In the presence of nonprotein thiols, the nitroxide radicals in QDs–AT were converted to hydroxylamines, resulting in the fluorescence recovery of the quenched QDs. The detection mechanism of the probe was investigated using Rh-Se-2 probe. The nanoprobe has high sensitivity toward glutathione (GSH) with a detection limit of 7.1 × 10−8 M. The fluorescent imaging of living cells showed that QDs–AT could distinguish the concentration differences of GSH in HL-7702 and HepG2 cells.
Co-reporter:Feng Li, Yan Feng, Pingjun Dong, Limin Yang, Bo Tang
Biosensors and Bioelectronics 2011 Volume 26(Issue 5) pp:1947-1952
Publication Date(Web):15 January 2011
DOI:10.1016/j.bios.2010.07.076
A novel protocol for development of DNA electrochemical biosensor based on gold nanoparticles (AuNPs) modified glassy carbon electrode (GCE) was proposed, which was carried out by the self-assembly of AuNPs on the mercaptophenyl film (MPF) via simple electrografting of in situ generated mercaptophenyl diazonium cations. The resulting MPF was covalently immobilized on GCE surface via C–C bond with high stability, which was desirable in fabrication of excellent performance biosensors. Probe DNA was self-assembled on AuNPs through the well-known Au–thiol binding. The recognition of fabricated DNA electrochemical biosensor toward complementary single-stranded DNA was determined by differential pulse voltammetry with the use of Co(phen)33+ as the electrochemical indicator. Taking advantage of amplification effects of AuNPs and stability of MPF, the developed biosensor could detect target DNA with the detection limit of 7.2 × 10−11 M, which also exhibits good selectivity, stability and regeneration ability for DNA detection.
Co-reporter:Mei Xue, Xu Wang, Hui Wang, Bo Tang
Talanta 2011 Volume 83(Issue 5) pp:1680-1686
Publication Date(Web):15 February 2011
DOI:10.1016/j.talanta.2010.11.064
In this paper, different sizes of glutathione-capped CdTe (GSH/CdTe) quantum dots (QDs) have been prepared directly in aqueous solution. The QDs have tunable fluorescence in the range of 510–670 nm, and they also have high photoluminescence quantum yield (PLQY) without any postpreparative treatment. Furthermore, the QDs have strong resistance to photobleaching, and they also have to be considered as cytocompatible. In addition, for the first time, folic acid was covalently conjugated to the GSH/CdTe QDs for imaging of cancer cells, demonstrating their potentially broad application as biolabels.
Co-reporter:Jiangwei Tian;Huachao Chen;Linhai Zhuo;Yanxia Xie;Na Li ; Bo Tang
Chemistry - A European Journal 2011 Volume 17( Issue 24) pp:6626-6634
Publication Date(Web):
DOI:10.1002/chem.201100148
Abstract
Peroxynitrite (ONOO−) is a highly reactive species implicated in the pathology of numerous diseases and there is currently great interest in developing fluorescent probes that can selectively detect ONOO− in living cells. Herein, a polymeric micelle-based and cell-penetrating peptide-coated fluorescent nanoprobe that incorporates ONOO− indicator dye and reference dye for the ratiometric detection and imaging of ONOO− has been developed. The nanoprobe effectively avoids the influences from enzymatic reaction and high-concentration .OH and ClO−. The improved ONOO− selectivity of the nanoprobe is achieved by a delicate complementarity of properties between the nanomatrix and the embedded molecular probe (BzSe-Cy). This nanoprobe also has other attractive properties, such as good water solubility, photostability, biocompatibility, and near-infrared excitation and emission. Fluorescence imaging experiments by confocal microscopy show that this nanoprobe is capable of visualizing ONOO− produced in living cells and it exhibits very low toxicity and good membrane permeability. We anticipate that this technique will be a potential tool for the precise pathological understanding and diagnosis of ONOO−-related human diseases.
Co-reporter:Dr. Ping Li;Libo Fang;Hui Zhou;Wen Zhang;Dr. Xu Wang;Dr. Na Li; Hongbo Zhong ; Bo Tang
Chemistry - A European Journal 2011 Volume 17( Issue 38) pp:10520-10523
Publication Date(Web):
DOI:10.1002/chem.201101327
Co-reporter:Guangming Qiao;Yuan Gao;Na Li;Zhengze Yu;Linhai Zhuo ; Bo Tang
Chemistry - A European Journal 2011 Volume 17( Issue 40) pp:11210-11215
Publication Date(Web):
DOI:10.1002/chem.201100658
Abstract
The successful treatment of most cancers depends on early detection. Tumor mRNA as a specific marker provides new avenues to monitor tumor progression in the early stages and assesses response to treatment. However, single tumor mRNA testing usually yields “false positive” results because cancer is associated with multiple tumor mRNA. It is indispensable to develop simple and effective approaches for the detection of multiple tumor mRNA. In this study, we used a combination of tumor-specific mRNA markers to avoid the inherent limitations associated with the single-marker technique. A gold nanoparticle (AuNP) was assembled with a bi-molecular beacon (bi-MB), and termed AuNP/bi-MB, which simultaneously targeted to two types of tumor mRNA in breast cancer cells. This imaging agent could prevent effectively false positive results and provide comprehensive and dependable information for the early detection of cancer. It would be beneficial to identify the stage of tumor progression and assess treatment decisions with the real-time detection of the relative expression levels of tumor mRNA in cancer cells. This strategy would offer an appealing approach toward the early detection of cancer by using multianalysis of tumor mRNA.
Co-reporter:Lei Wang, Jinhua Zhan, Weiliu Fan, Guanwei Cui, Honggang Sun, Linhai Zhuo, Xian Zhao and Bo Tang
Chemical Communications 2010 vol. 46(Issue 46) pp:8833-8835
Publication Date(Web):18 Oct 2010
DOI:10.1039/C0CC03660A
Microcrystalline sodium tungsten bronze nanowire bundles were obtained via a facile hydrothermal synthesis, and were applied in water purification as visible-light-driven photocatalysts for the first time.
Co-reporter:Zhenzhen Chen, Qingling Li, Xu Wang, Zhiyuan Wang, Ruirui Zhang, Miao Yin, Lingling Yin, Kehua Xu and Bo Tang
Analytical Chemistry 2010 Volume 82(Issue 5) pp:2006
Publication Date(Web):February 9, 2010
DOI:10.1021/ac902741r
The first application of microchip electrophoresis with laser-induced fluorescence (MCE-LIF) detection to simultaneously determine glutathione (GSH) and hydrogen peroxide (H2O2) in mitochondria was described. Organoselenium probe Rh-Se-2 and bis(p-methylbenzenesulfonate)dichlorofluorescein (FS) synthesized in our laboratory were utilized as fluorescent probes for GSH and H2O2, respectively. Rh-Se-2, which is nonfluorescent, reacts with GSH to produce rhodamine 110 (Rh110) with high quantum yield. Similarly, nonfluorescent FS reacts with H2O2 and produces dichlorofluorescein (DCF) accompanied by drastic fluorescence enhancement. Both probes exhibit good sensitivity toward their respective target molecule determination. Fast, simple, and sensitive determination of GSH and H2O2 was realized within 37 s using a running buffer of 50 mM mannitol, 40 mM HEPES (pH 7.4), and an electric field of 360 V/cm for separation. The linear ranges of the method were 3.3 × 10−9−1.0 × 10−7 M/2.9 × 10−7−1.0 × 10−4 M and 2.7 × 10−9−4.0 × 10−7 M with detection limits (signal-to-noise ratio = 3) of 1.3 nM (0.16 amol) and 1.0 nM (0.12 amol) for GSH and H2O2, respectively. The relative standard deviations (RSDs) of migration time and peak area were less than 1.0% and 4.0%, respectively. The MCE-LIF assay was utilized to investigate the levels of GSH and H2O2 in mitochondria isolated from HepG2 cells and were found to be 2.01 ± 0.21 mM and 5.36 ± 0.45 μM, respectively. The method was further extended to observe situations of the two species in mitochondria of HepG2 cells experiencing cell apoptosis that were induced by doxorubicin and photodynamic therapy (PDT).
Co-reporter:Kehua Xu, Yun Zhang, Bo Tang, Julia Laskin, Patrick J. Roach and Hao Chen
Analytical Chemistry 2010 Volume 82(Issue 16) pp:6926
Publication Date(Web):July 16, 2010
DOI:10.1021/ac1011602
This paper reports a systemic mass spectrometry (MS) investigation of a novel strategy for labeling biological thiols, involving the cleavage of the Se−N bond by thiol to form a new Se−S bond. Our data show that the reaction is highly selective, rapid, reversible, and efficient. Among 20 amino acids, only cysteine is reactive toward Se−N containing reagents and the reaction occurs in seconds. With the addition of dithiothreitol, peptides derivatized by selenium reagents can be recovered. The high reaction selectivity and reversibility provide potential in both selective identification and isolation of thiols from mixtures. Also, with dependence on the selenium reagent used, derivatized peptide ions exhibit tunable dissociation behaviors (either facile cleavage or preservation of the formed Se−S bond upon collision-induced dissociation), a feature that is useful in proteomics studies. Equally importantly, the thiol derivatization yield is striking, as reflected by 100% conversion of protein β-lactoglobulin A using ebselen within 30 s. In addition, preliminary applications such as rapid screening of thiol peptides from mixtures and identification of the number of protein free and bound thiols have been demonstrated. The unique selenium chemistry uncovered in this study would be valuable in the MS analysis of thiols and disulfide bonds of proteins/peptides.
Co-reporter:Mei Xue, Xiaohua Zhang, Xu Wang, Bo Tang
Materials Letters 2010 Volume 64(Issue 12) pp:1357-1360
Publication Date(Web):30 June 2010
DOI:10.1016/j.matlet.2010.03.045
In the current paper, novel multi-trunk CdS dendrites were synthesized via a simple hydrothermal system, employing CdCl2·2H2O and KSCN as the starting materials. No extra surfactants were used. The observations from TEM and SEM showed that the product composed of a few long central trunks with secondary branches, which preferentially grew in a parallel direction with a definite angle to the trunks. Selected area electron diffraction (SAED) patterns confirmed that the dendrite was single crystalline in nature. X-ray diffraction analyses proved that the CdS dendrites were pure hexagonal structure. On the basis of the experimental results, a possible growth process has been discussed.
Co-reporter:Na LI, Guang-Ming QIAO, Lin-Hai ZHUO, Bo TANG
Chinese Journal of Analytical Chemistry 2010 Volume 38(Issue 1) pp:138-142
Publication Date(Web):January 2010
DOI:10.1016/S1872-2040(09)60019-0
Co-reporter:Feng Li, Yan Feng, Pingjun Dong, Bo Tang
Biosensors and Bioelectronics 2010 Volume 25(Issue 9) pp:2084-2088
Publication Date(Web):15 May 2010
DOI:10.1016/j.bios.2010.02.004
A novel protocol for the gold nanoparticles (AuNPs) modification on the electrode surface was proposed, which was based on the self-assembly of AuNPs on the mercapto-diazoaminobenzene monolayer modified electrode. The mercapto-diazoaminobenzene monolayer was obtained by covalent immobilization of 4-aminothiophenol (4-ATP) molecules onto another 4-ATP monolayer functionalized gold electrode by diazotization-coupling reaction. The DNA immobilization and hybridization on the AuNPs modified electrode was further investigated. The prepared AuNPs–ATP–diazo-ATP film demonstrated efficient electron transfer ability for the electroactive species toward the electrode surface due to a large conjugated structure of the mercapto-diazoaminobenzene monolayer. The recognition of fabricated electrochemical DNA biosensor toward complementary single-stranded DNA was determined by differential pulse voltammetry with the use of Co(phen)33+ as an electrochemical indicator. A linear detection range for the complementary target DNA was obtained from 3.01 × 10−10 to 1.32 × 10−8 M with a detection limit of 9.10 × 10−11 M. The fabricated biosensor also possessed good selectivity and could be regenerated easily.
Co-reporter:Ping Li Dr.;Ting Xie;Xia Duan;Fabiao Yu;Xu Wang Dr. Dr.
Chemistry - A European Journal 2010 Volume 16( Issue 6) pp:1834-1840
Publication Date(Web):
DOI:10.1002/chem.200901514
Abstract
A new nonredox fluorescent probe to realize the imaging of hydroxyl radicals (.OH) in living cells was designed and synthesized. The structure comprised the fluorescent dye boron dipyrromethene (BDP) and a 2,2,6,6-tetramethyl-1-piperidinoxyl (TEMPO) unit. This probe could rapidly respond to .OH with a detection limit of 18 pM, and it possessed superior photostability and pH insensitivity. Other reactive oxygen species (ROS) and relevant intracellular components did not interfere. In particular, the important problem of ONOO− interference was efficiently avoided. An MTT assay proved that the probe was not very cytotoxic. The probe could penetrate into intact cell membranes to selectively detect intracellular .OH without causing cellular damage in living mice macrophages, normal human liver cells. and human hepatoma cells. These advantageous characteristics make the fluorescent probe potentially useful as a new candidate to detect .OH in broad biosystems.
Co-reporter:Feng Li, Yan Feng, Zhen Wang, Limin Yang, Linhai Zhuo, Bo Tang
Biosensors and Bioelectronics 2010 Volume 25(Issue 10) pp:2244-2248
Publication Date(Web):15 June 2010
DOI:10.1016/j.bios.2010.03.006
A mediator-free hydrogen peroxide (H2O2) biosensor was fabricated based on immobilization of horseradish peroxidase (HRP) on layered calcium carbonate–gold nanoparticles (CaCO3–AuNPs) inorganic hybrid composite. The proposed biosensor showed a strong electrocatalytic activity toward the reduction of H2O2, which could be attributed to the favored orientation of HRP in the well-confined surface as well as the high electrical conductivity of the resulting CaCO3–AuNPs inorganic hybrid composite. The hybrid composite was obtained by the adsorption of AuNPs onto the surfaces of layered CaCO3 through electrostatic interaction. The key analytical parameters relative to the biosensor performance such as pH and applied potential were optimized. The developed biosensor also exhibited a fast amperometric response (3 s), a good linear response toward H2O2 over a wide range of concentration from 5.0 × 10−7 to 5.2 × 10−3 M, and a low detection limit of 1.0 × 10−7 M. The facile, inexpensive and reliable sensing platform based on layered CaCO3–AuNPs inorganic hybrid composite should hold a huge potential for the fabrication of more other biosensors.
Co-reporter:Jie Ding, Xu Wang, Lin-Hai Zhuo and Bo Tang
Journal of Materials Chemistry A 2009 vol. 19(Issue 19) pp:3027-3032
Publication Date(Web):17 Mar 2009
DOI:10.1039/B819230H
High aspect ratio CdTe nanostructures were fabricated by hierarchical assembly of nanoparticles at the water–oil interface. The nature of two distinct morphologies, nanotubes and nanowires, was explored as a function of preparation parameters. Semiconductor CdTe nanoparticles covered with a mixed monolayer of n-dodecanethiol and thioglycollic acid were prepared and found to mediate the oil–water interface by assembly. CdTe nanoparticles in water phase, as starting materials, initiated the synthesis of nanotubes and nanowires. Acetone as an additional component was crucial in the phase transfer process. Some factors, including reaction temperature, reaction time, additional components, and reactant ratio, controlled the morphology of the products. The present method could be readily used to construct nanostructures possessing biological application potentials.
Co-reporter:Bo Tang, Lingling Yin, Xu Wang, Zhenzhen Chen, Lili Tong and Kehua Xu
Chemical Communications 2009 (Issue 35) pp:5293-5295
Publication Date(Web):28 Jul 2009
DOI:10.1039/B909542J
A novel organoselenium fluorescent probe (Rh-Se-2), which features a high signal-to-noise ratio (up to 170-fold), fast response (5 min) and excellent immunity to interferences, was designed, synthesized and applied to bioimaging.
Co-reporter:Hongmin Li, Qingling Li, Xu Wang, Kehua Xu, Zhenzhen Chen, Xiaocong Gong, Xin Liu, Lili Tong and Bo Tang
Analytical Chemistry 2009 Volume 81(Issue 6) pp:2193
Publication Date(Web):February 10, 2009
DOI:10.1021/ac801777c
A method for the first time to simultaneously determine superoxide and hydrogen peroxide in macrophage RAW 264.7 cell extracts by microchip electrophoresis with laser-induced fluorescence detection (MCE-LIF) was developed. 2-Chloro-1,3-dibenzothiazolinecyclohexene (DBZTC) and bis(p-methylbenzenesulfonyl) dichlorofluorescein (FS), two probes that can be specifically derivatized by superoxide and hydrogen peroxide, respectively, were synthesized and used. Parameters influencing the derivatization and on-chip separation were optimized. With the use of a HEPES (20 mM, pH 7.4) running buffer, a 50 mm long separation channel, and a separation voltage of 1800 V, baseline separation was achieved within 48 s for the two derivatization products, DBZTC-oxide (DBO) and 2,7-dichlorofluorescein (DCF). The linearity ranges of the method were 0.08−5.0 and 0.02−5.0 μM with detection limits (signal-to-noise ratio = 3) of 10 nM (1.36 amol) and 5.6 nM (0.76 amol) for superoxide and hydrogen peroxide, respectively. The relative standard deviations (RSDs) of migration time and peak area were less than 2.0% and 5.0%, respectively. The recoveries of the cell extract samples spiked with 1.0 μM standard solutions were 96.1% and 93.0% for superoxide and hydrogen peroxide, respectively. With the use of this method, superoxide and hydrogen peroxide in phorbol myristate acetate (PMA)-stimulated macrophage RAW 264.7 cell extracts were found to be 0.78 and 1.14 μM, respectively. The method has paved a way for simultaneously determining two or more reactive oxygen species (ROS) in a biological system with high resolution.
Co-reporter:Linhai Zhuo, Jiechao Ge, Lihua Cao and Bo Tang
Crystal Growth & Design 2009 Volume 9(Issue 1) pp:1
Publication Date(Web):December 4, 2008
DOI:10.1021/cg070482r
In this paper, CoO, Co3O4, Ni(OH)2, and Mg(OH)2 nanotubes were synthesized by solvothermal treatment of corresponding colloidal hydroxide. These nanotubes were characterized by powder X-ray diffraction (XRD), selected area electron diffraction (SAED), and transmission electron microscopy (TEM). According to the time-dependent morphology evolution, it is likely that the growth is governed by a solution−solid process. Advantages of this method include that it is a simple and general process without the need for a catalyst, surfactant, or template, which makes it low cost, and that the raw materials are readily available. On the basis of the above results, other metal hydroxides with layered structure are therefore potentially capable of forming nanotubes.
Co-reporter:Fabiao Yu, Wenshen Zhang, Ping Li, Yanlong Xing, Lili Tong, Jianping Ma and Bo Tang
Analyst 2009 vol. 134(Issue 9) pp:1826-1833
Publication Date(Web):17 Jul 2009
DOI:10.1039/B823360H
A new fluorescent and colorimetric Cu2+ probe was synthesized, and realized optical imaging in RAW264.7 macrophages. The design strategy was based on a change in structure between spirocyclic (non-fluorescent) and ring-open (fluorescent) forms of rhodamine-based dyes, and its crystal structure was presented to explain the binding mode. Upon treatment with Cu2+, the weakly fluorescent probe exhibited a strong fluorescence response, high selectivity and was quantitative for Cu2+ under physiological conditions. In addition, the off–on-type fluorescent change upon the addition of Cu2+ was also applied in bioimaging.
Co-reporter:Ling-Ling YIN, Zhen-Zhen CHEN, Li-Li TONG, Ke-Hua XU, Bo TANG
Chinese Journal of Analytical Chemistry 2009 Volume 37(Issue 7) pp:1073-1081
Publication Date(Web):July 2009
DOI:10.1016/S1872-2040(08)60117-6
Thiols, which are the components of many proteins and simple molecules, play an important role in the cellular antioxidant defense, and their concentration level is directly linked to many diseases. Therefore, real-time quantitative determination of thiols is of vital significance in biochemistry and clinical chemistry. Fluorescent probe-based detection, which is highly sensitive and specific, is one of the most powerful and attractive tools used in thiols determination, especially in living cell imaging. This review summarizes the recent progress in thiols detection by fluorescent probes. The contents were described and discussed in terms of different reaction mechanisms between fluorescent probes and thiols. Particularly, future studies and prospects were envisioned.
Co-reporter:Qingling Li, Hui Zhang, Yan Wang, Bo Tang, Xin Liu, Xiaocong Gong
Sensors and Actuators B: Chemical 2009 Volume 136(Issue 1) pp:265-274
Publication Date(Web):2 February 2009
DOI:10.1016/j.snb.2008.10.066
A versatile programmable eight-path-electrode power supply (PEPS) system for manipulating microfluids of a complex microfluidic chip has been developed. The PEPS system consisted of a single chip microprocessor as a central control unit and a personal computer (PC) as an upper computer, and the program could be operated under Windows98/2000/XP. The voltage output of each electrode was in the range of 0 to +8000 V (0.1% precision) while the current output was in the range of 0 to +999 μA. The voltage of eight electrodes could be operated either independently or synchronously by random combination of any electrodes through switching. The voltage output modes were “switch-off/floating”, “switch-on” and “grounded” and fast switched at ms-level between these modes, and run time (0.1 s precision) of these modes could be controlled as desired. The PEPS system was conveniently for controlling flow rate and direction of electroosmotic flow (EOF) in a chip network. Six electrodes were chosen to control the repeated ‘injection and separation’ of 1.0 × 10−5 M fluorescein isothiocyanate (FITC) in a six-reservoir glass-based chip. The relative standard deviation (R.S.D., n = 4, S/N = 10) of the repeated operation was 0.9% for the reservation time (tR) and 2.3% for the peak height, respectively.
Co-reporter:Zhenzhen Chen;Ning Zhang;Linhai Zhuo
Microchimica Acta 2009 Volume 164( Issue 3-4) pp:311-336
Publication Date(Web):2009 March
DOI:10.1007/s00604-008-0048-8
An overview is presented on catalytic kinetic methods for heavy metal determination by photometry or fluorometry reported in recent years. The article summarizes the analytical procedures, the kinetics and reaction mechanisms of some typical methods, and their applications to real sample determination.
Co-reporter:KeHua Xu;Fen Liu;HuiXia Wang;ShanShan Wang
Science China Chemistry 2009 Volume 52( Issue 6) pp:734-740
Publication Date(Web):2009 June
DOI:10.1007/s11426-009-0109-9
Based on the mechanism of H2O2-mediated hydrolysis of sulfonates, two fluorescein disulfonates compounds (FS-1 and FS-2) were designed and synthesized as the highly selective and sensitive fluorescent probes for imaging H2O2 in living cells. The probes were detected with elemental analysis, IR, 1H NMR and 13C NMR. Upon reaction with H2O2, the probes exhibit strong fluorescence responses and high selectivity for H2O2 over other reactive oxygen species and some biological compounds. Furthermore, the sulfonate-based probes, as novel fluorescent reagents, are cell-permeable and can detect micromolar changes in H2O2 concentrations in living cells by using confocal microscopy.
Co-reporter:Bo Tang ;Baiyu Ding Dr.;Kehua Xu Dr. ;Lili Tong Dr.
Chemistry - A European Journal 2009 Volume 15( Issue 13) pp:3147-3151
Publication Date(Web):
DOI:10.1002/chem.200802165
Co-reporter:Ruirui Zhang, Chuanliu Wu, Lili Tong, Bo Tang and Qing-Hua Xu
Langmuir 2009 Volume 25(Issue 17) pp:10153-10158
Publication Date(Web):July 28, 2009
DOI:10.1021/la902235d
Here we report the preparation of a novel multifunctional core−shell nanocomposite material that contains a nonporous dye-doped silica core and a mesoporous silica shell containing photosensitizer molecules, hematoporphyrin (HP). This architecture allows simultaneous fluorescence imaging and photosensitization treatment. The photosensitizer molecules are covalently linked to the mesoporous silica shell and exhibit excellent photo-oxidation efficiency. The efficiency of photo-oxidation of the core−shell hybrid nanoparticles was demonstrated to be significantly improved over that in the homogeneous solution. The mesoporous silica nanovehicle acts not only as a carrier for the photosensitizers but also as a nanoreactor to facilitate the photo-oxidation reaction. The doping of fluorescence dyes into the nonporous core endows the imaging capability, which has been demonstrated with cell imaging experiments. This approach could be easily extended to conjugate other functional regents if necessary. These multifunctional nanovehicles possess unique advantages in acting as nanocarriers in photodynamic therapy to allow simultaneous high-resolution targeting and treatment.
Co-reporter:Jixi Hu, Lingling Yin, Kehua Xu, Jingjing Gao, Lili Tong, Bo Tang
Analytica Chimica Acta 2008 Volume 606(Issue 1) pp:57-62
Publication Date(Web):7 January 2008
DOI:10.1016/j.aca.2007.10.055
Based on a photoelectron transfer (PET) mechanism, vicinal diaminobenzoacridine (VDABA), a fluorescent probe for the determination of trace amounts of nitric oxide radical in biological sample, was synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectrum. Combining a flow injection with spectrofluorimetry, a high-throughput method for detecting NO was obtained, which was successfully applied to the determination of NO in the human serum. The proposed method was simple, rapid, precise and automatic. Under optimum conditions, the linear calibration range was from 1.1 × 10−7 to 5.0 × 10−6 M and the detection limit was 3.1 × 10−8 M. Furthermore, the probe could make cell-derived NO “visible” by using confocal laser scanning microscope.
Co-reporter:Ping Li, Bo Tang, Yanlong Xing, Puming Li, Guiwen Yang and Liang Zhang
Analyst 2008 vol. 133(Issue 10) pp:1409-1415
Publication Date(Web):15 May 2008
DOI:10.1039/B802836B
An NIR (near-infrared) fluorescent probe TCP (tricarbocyanine diphenylphosphine) including a non-conjugated ‘pre-tricarbocyanine’ was designed and synthesized for visualizing lipid hydroperoxides (ROOH) in living cells. The excitation and emission spectra of tricarbocyanine in the NIR region can effectively avoid background fluorescence interference in biological systems. The probe exhibited a rapid fluorescence response to ROOH and high selectivity for ROOH over other ROS (reactive oxygen species) and some biological compounds, and the limit of detection was 38 pM. In addition, the probe was stable, and less cytotoxic, which indicated that it has potential application in detecting lipid hydroperoxides in living biological systems.
Co-reporter:Ning Zhang, Yuanyuan Liu, Lili Tong, Kehua Xu, Linhai Zhuo and Bo Tang
Analyst 2008 vol. 133(Issue 9) pp:1176-1181
Publication Date(Web):19 Jun 2008
DOI:10.1039/B803226B
A novel assembly of Au NPs–β-CDs–FL for the fluorescent probing of cholesterol (Cho) is provided. Gold nanoparticles (Au NPs) possessing a high extinction coefficient function can be used as excellent fluorescent quenchers in Au NP–fluorophore composites. Inclusion of fluorescein (FL) into β-cyclodextrin (β-CD) makes fluorescence resonance energy transfer (FRET) occur through the donor and quencher nearby. FRET switches off because of the cholesterol-induced release of FL from β-CD cavity, which results in the fluorescence recovery of the quenched dye. Spectral analysis supported the idea that the signal enhancement was attributed to the formation of an inclusion complex of the cholesterol moiety in β-CD, resulting in separation of FL from the Au NPs. This phenomenon is explained by the guest-induced location change of the FL from inside to outside the cavity, suggesting that the assembly of Au NPs–β-CDs–FL is effective as a fluorescent probe for cholesterol recognition. The fluorescence increase is proportional to the concentration of cholesterol in the range of approx. 30 nM to 15 μM. A concentration of cholesterol as low as 9 nM would be readily detected. The precision of the method applied to the determination of quantities of cholesterol present in human blood serum were satisfactory.
Co-reporter:Bo Tang ;Ning Zhang Dr.;Zhenzhen Chen;Kehua Xu;Linhai Zhuo;Liguo An ;Guiwen Yang
Chemistry - A European Journal 2008 Volume 14( Issue 2) pp:522-528
Publication Date(Web):
DOI:10.1002/chem.200700455
Abstract
The incorporation of gold nanoparticles (Au NPs) as quencher modules in fluorescent probes for DNA damage caused by intracellular hydroxyl radicals (HO.) is reported. Au NPs of 15 nm diameter were decorated with DNA oligomers terminating in thiol functions in their 3′ positions and possessing 5′ fluorophore modifications. The Au NPs, which have high extinction coefficients, functioned as excellent fluorescent quenchers in the fluorophore–Au NP composites. FRET is switched off as a factor of HO.-induced strand breakage in the single-stranded DNAs, restoring the fluorescence of the quenched fluorophores, which can be followed by spectrofluorimetry. In vitro assays with HO.-generating Fenton reagent demonstrated increases in fluorescence intensity with a linear range from 8.0 nM to 1.0 μM and a detection limit as low as 2.4 nM. Confocal microscopic imaging of macrophages and HepG2 revealed that the probe is cell-permeable and intracellular HO.-responsive. The unique combination of good selectivity and high sensitivity establishes the potential value of the probe for facilitating investigations of HO.-mediated cellular homeostasis and injury.
Co-reporter:Bo Tang ;Lihua Cao Dr.;Kehua Xu;Linhai Zhuo;Jiechao Ge;Qingling Li ;Lijuan Yu
Chemistry - A European Journal 2008 Volume 14( Issue 12) pp:3637-3644
Publication Date(Web):
DOI:10.1002/chem.200701871
Abstract
A novel assembled nanobiosensor QDs-ConA-β-CDs-AuNPs was designed for the direct determination of glucose in serum with high sensitivity and selectivity. The sensing approach is based on fluorescence resonance energy transfer (FRET) between CdTe quantum dots (QDs) as an energy donor and gold nanoparticles (AuNPs) as an energy acceptor. The specific combination of concanavalin A (ConA)-conjugated QDs and thiolated β-cyclodextrins (β-SH-CDs)-modified AuNPs assembles a hyperefficient FRET nanobiosensor. In the presence of glucose, the AuNPs-β-CDs segment of the nanobiosensor is displaced by glucose which competes with β-CDs on the binding sites of ConA, resulting in the fluorescence recovery of the quenched QDs. Experimental results show that the increase in fluorescence intensity is proportional to the concentration of glucose within the range of 0.10–50 μM under the optimized experimental conditions. In addition, the nanobiosensor has high sensitivity with a detection limit as low as 50 nM, and has excellent selectivity for glucose over other sugars and most biological species present in serum. The nanobiosensor was applied directly to determine glucose in normal adult human serum, and the recovery and precision of the method were satisfactory. The unique combination of high sensitivity and good selectivity of this biosensor indicates its potential for the clinical determination of glucose directly and simply in serum, and provides the possibility to detect low levels of glucose in single cells or bacterial cultures. Moreover, the designed nanobiosensor achieves direct detection in biological samples, suggesting the use of nanobiotechnology-based assembled sensors for direct analytical applications in vivo or in vitro.
Co-reporter:Lihua Cao Dr.;Jian Ye;Lili Tong
Chemistry - A European Journal 2008 Volume 14( Issue 31) pp:9633-9640
Publication Date(Web):
DOI:10.1002/chem.200800681
Abstract
A new complex consisting of CdTe quantum dots (QDs) and glucose oxidase (GOx) has been facilely assembled to achieve considerably enhanced enzymatic activity and a wide active temperature range of GOx; these characteristics are attributed to the conformational changes of GOx during assembly. The obtained complex can be simultaneously used as a nanosensor for the detection of glucose with high sensitivity. A mechanism is put forward based on the fluorescence quenching of CdTe QDs, which is caused by the hydrogen peroxide (H2O2) that is produced from the GOx-catalyzed oxidation of glucose. When H2O2 gets to the surface of the CdTe QDs, the electron-transfer reaction happens immediately and H2O2 is reduced to O2, which lies in electron hole traps on CdTe QDs and can be used as a good acceptor, thus forming the nonfluorescent CdTe QDs anion. The produced O2 can further participate in the catalyzed reaction of GOx, forming a cyclic electron-transfer mechanism of glucose oxidation, which is favorable for the whole reaction system. The value of the Michaelis–Menton constant of GOx is estimated to be 0.45 mM L−1, which shows the considerably enhanced enzymatic activity measured by far. In addition, the GOx enzyme conjugated on the CdTe QDs possesses better thermal stability at 20–80 °C and keeps the maximum activity in the wide range of 40–50 °C. Moreover, the simply assembled complex as a nanosensor can sensitively determine glucose in the wide concentration range from micro- to millimolar with the detection limit of 0.10 μM, which could be used for the direct detection of low levels of glucose in biological systems. Therefore, the established method could provide an approach for the assembly of CdTe QDs with other redox enzymes, to realize enhanced enzymatic activity, and to further the design of novel nanosensors applied in biological systems in the future.
Co-reporter:Bo Tang;Li Juan Cui;Ke Hua Xu;Li Li Tong;Gui Wen Yang;Li Guo An
ChemBioChem 2008 Volume 9( Issue 7) pp:1159-1164
Publication Date(Web):
DOI:10.1002/cbic.200800001
Abstract
A new mercury(II) near-infrared region fluorescent probe 3,9-dithia-6-monoazaundecane-tricarbocyanine has been designed and synthesized. It consists of two functional moieties: the tricarbocyanine performs as the near-infrared region fluorophore, and the 3,9-dithia-6-monoazaundecane acts as the selected binding site for metal ions. The near-IR excitation and emission profiles of the probe can minimize cell and tissue damage and avoid native fluorescence from natural cellular species. It exhibits fluorescence increase upon the binding of the Hg2+ based on the inhibition of the photoinduced electron transfer quenching mechanism. Excellent sensitivity and selectivity for mercuric ions are observed with this probe. The value of the system is demonstrated by its use in monitoring the real-time uptake of Hg2+ within HepG2 cells and five day old zebrafish. The synthesis and remarkable properties of it help to extend the development of metal ions fluorescent probes for biological applications.
Co-reporter:Bo Tang, Xia Liu, Kehua Xu, Hui Huang, Guiwen Yang and Liguo An
Chemical Communications 2007 (Issue 36) pp:3726-3728
Publication Date(Web):09 Jul 2007
DOI:10.1039/B707173F
A dual near-infrared pH fluorescent probe has been designed, synthesized and applied to HepG2 cells, with a pKa value of 5.14 under acidic conditions and 11.31 under basic conditions, which is valuable for studying acidic organelles in living cells and pH changes in chemical systems.
Co-reporter:Hui Huang;Fang Liu;Bao-Xiu Jia;Ke-Hua Xu;Zhen-Zhen Chen
Chinese Journal of Chemistry 2007 Volume 25(Issue 3) pp:
Publication Date(Web):5 MAR 2007
DOI:10.1002/cjoc.200790065
The supramolecular interaction of gemfibrozil with β-cyclodextrin (β-CD) was studied by spectrofluorimetry. The mechanism of the inclusion was discussed by spectrofluoremetry, infrared spectrum and 1H NMR spectrum. The results showed that a 1:1 (β-CD:gemfibrozil) complex was formed with an apparent association constant of 3.844×103 L·mol−1. Based on the enhancement of the fluorescent intensity of gemfibrozil, a spectrofluorimetric method for the determination of gemfibrozil in bulk aqueous solution in the presence of β-CD was developed. The linear range was 3.30 ng·mL−1–6.00 µg·mL−1 with the detection limit of 0.980 ng·mL−1. There was no interference from the excipients normally used in tablet composition and the serum main compositions. The proposed method was then successfully applied to the determination of gemfibrozil in capsules and serum.
Co-reporter:Xu Wang, Jing Wang, Yan Wang, Zhen Zhen Chen, Bo Tang
Journal of Photochemistry and Photobiology A: Chemistry 2007 Volume 186(2–3) pp:194-201
Publication Date(Web):25 February 2007
DOI:10.1016/j.jphotochem.2006.08.004
A strong and reproducible room temperature phosphorescence (RTP) signal (λex/λem = 298/481 nm) coming from a 1:1:1 β-cyclodextrin (β-CD)/thiabendazole (TBZ)/Triton X-100 (TX-100) supramolecular ternary inclusion complex was induced by KI, which act as a heavy-atom perturber without removing dissolved oxygen from solution. The multirecognition mechanism of the β-cyclodextrin (β-CD)/thiabendazole (TBZ)/Triton X-100 (TX-100) supramolecular ternary inclusion was studied and discussed by means of phosphorescence spectrum, surface tension of the solution, infra-red spectrograms and 1H NMR spectroscopy. Results showed that the phenyl ring of TBZ and the hydrophobic hydrocarbon chain of TX-100 could enter the hydrophobic cavity of the β-CD to form supramolecular ternary inclusion, which provided an effective protection for RTP of TBZ. Compared with the method using chemical oxygen scavenger, the heavy-atom concentration of the proposed method was decreased about four times, the lifetime of the phosphorescence was prolonged nine times, and the pH range of the supramoleculer interaction was greatly broadened.
Co-reporter:Fang Liu, Hui-ling Liang, Ke-hua Xu, Li-li Tong, Bo Tang
Talanta 2007 Volume 74(Issue 1) pp:140-145
Publication Date(Web):15 November 2007
DOI:10.1016/j.talanta.2007.05.048
The supramolecular interaction of β-cyclodextrin dimer with berberine hydrochloride was studied in aqueous KH2PO4–H3PO4 buffer solution of pH 2.00 at room temperature by spectrofluorimetry. The apparent association constant of the complex was 1.53 × 104 L mol−1. Based on the significant enhancement of fluorescence intensity of supramolecular sandwich complexes, a spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of berberine hydrochloride in aqueous solution in presence of ethylenediamine linked β-CD dimer. The linear range of the method was 12.8–1.00 × 104 ng mL−1 with the detection limit 3.6 ng mL−1. There was no interference from the normally used in tablets and serum constituents. The proposed method was successfully applied to the determination of berberine hydrochloride in tablets and serum. And then it has a promising potential in therapeutic drug monitoring, pharmokinetis and clinical application.
Co-reporter:Ning Zhang;Qing-Cheng Kong;Zhen-Zhen Chen;Ke-Hua Xu
Microchimica Acta 2007 Volume 158( Issue 1-2) pp:165-171
Publication Date(Web):2007 April
DOI:10.1007/s00604-006-0707-6
A sensitive catalytic kinetic spectrofluorimetric approach for determining ng mL−1 levels of rhodium is presented, and the possible mechanism of the catalytic reaction was investigated. The determination is based on the catalytic property of rhodium to enhance the reaction of o-vanillin salicylhydrazone (OVSH) with potassium bromate in a water-ethanol medium at pH 4.80 and 45 °C. The presence of β-cyclodextrin (β-CD) obviously sensitized the assay due to its high inclusion ability towards OVSH. Under optimized experimental conditions, fluorescence measurements of the β-CD-rhodium-KBrO3-OVSH catalytic kinetic reaction system were carried out in its fluorescent band centered at λex = 333 nm and λem = 476 nm, respectively. The calibration graph was linear over the concentration range of 0.47–100 ng mL−1 with a detection limit of 0.14 ng mL−1. The effect of interferences was discussed, and the results show that the extraction method can be used to separate rhodium from interference species such as iridium. The proposed method, applied to several synthetic mixtures containing rhodium mixed with varying amounts of metal salts, produced satisfactory results.
Co-reporter:Kehua Xu Dr.;Xia Liu ;Guiwen Yang ;Yong Yang ;Liguo An
Chemistry - A European Journal 2007 Volume 13(Issue 5) pp:
Publication Date(Web):30 OCT 2006
DOI:10.1002/chem.200600497
3′,6′-Bis(diphenylphosphinyl)fluorescein (PF-1) was synthesized as a highly selective and sensitive fluorescent probe for imaging O2.− in living cells. The design strategy for the probe was based on the nucleophilic mechanism of O2.− to mediate deprotection of this probe to give fluorescein. Upon reaction with O2.−, the probe exhibits a strong fluorescence response and high selectivity for O2.− over other reactive oxygen species and some biological compounds. The phosphinate-based probe, as a new fluorescent reagent, is cell-permeable and can detect micromolar changes of O2.− concentrations by using confocal microscopy in living cells. The unique combination of good selectivity, high sensitivity, good water solubility, and rapid reactivity establishes the potential value of the probe for facilitating investigations of the generation, metabolism, and mechanisms of superoxide-mediated cellular homeostasis and injury.
Co-reporter:Bo Tang, Hui Huang, Kehua Xu, Lili Tong, Guiwen Yang, Xia Liu and Liguo An
Chemical Communications 2006 (Issue 34) pp:3609-3611
Publication Date(Web):26 Jul 2006
DOI:10.1039/B606809J
A new highly sensitive and selective near-infrared fluorescent probe for zinc ion, based on photoinduced electron transfer (PET) mechanism, has been designed, synthesized, and applied to macrophage cells.
Co-reporter:Guangli Wang;Linhai Zhuo;Jiechao Ge;Mei Xue
European Journal of Inorganic Chemistry 2006 Volume 2006(Issue 11) pp:
Publication Date(Web):30 MAR 2006
DOI:10.1002/ejic.200500983
Single crystal β-MnO2 nanorods were successfully synthesized employing a facile in-situ redox precipitation hydrothermal process. The effects of various experimental conditions on the morphology of the products were investigated. The mechanism of formation of the nanorods was investigated and discussed based on the experimental results. The magnetic measurement of the nanorods with a diameter of 25–40 nm and a length of 240–440 nm indicates that the Néel magnetic transition temperature is about 6 K higher than that of the bulk β-MnO2 crystal. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Co-reporter:Bo Tang, Zhen-Zhen Chen, Ning Zhang, Jie Zhang, Yan Wang
Talanta 2006 Volume 68(Issue 3) pp:575-580
Publication Date(Web):15 January 2006
DOI:10.1016/j.talanta.2005.04.070
A novel host inclusion complex of cross-linking-polymeric-β-cyclodextrin-o-vanillin furfuralhydrazone (β-CDP-OVFH) was synthesized and characterized with IR and 1H NMR spectra to confirm its structure. A highly selective and sensitive fluorescent determination of trace amounts of gallium was proposed based on the reaction between Ga3+ with β-CDP-OVFH in acetic acid–ammonium acetate buffer medium of pH 4.10. The maximum excitation and emission wavelengths were 392 and 499 nm, respectively. The linear range of this method was 1.5–330 ng ml−1 with a detection limit of 0.44 ng ml−1. The effect of interferences in the determination of gallium was investigated and the results showed that the same race elements such as Al3+ and In3+ did not interfere the determination of Ga3+ even when their concentration is 100 times of Ga3+, the host reagent had quite high capacity of identifying Ga3+. This method was successfully applied to the determination of trace amounts of Ga3+ in artificial and semiconductor samples.
Co-reporter:Bo Tang, Li Zhang, Ke-hua Xu
Talanta 2006 Volume 68(Issue 3) pp:876-882
Publication Date(Web):15 January 2006
DOI:10.1016/j.talanta.2005.06.053
A new kind of near-infrared fluorescence agent, tricarbochlorocyanine dye (Cy.7.Cl), had been synthesized in house and used for near-infrared spectrofluorimetric determination of hydrogen peroxide (H2O2) by flow injection analysis (FIA) for the first time. The oxidation reaction of Cy.7.Cl with H2O2 occurred under the catalysis of horseradish peroxidase (HRP) and it was studied in detail. The possible reaction mechanism was discussed. Under optimal experimental conditions, fluorescence from Cy.7.Cl displayed excitation and emission maxima (ex/em) at 780 and 800 nm, respectively. The two linear working ranges were 1.86 × 10−7 to 4.11 × 10−7 mol L−1 and 4.11 × 10−7 to 7.19 × 10−6 mol L−1, respectively. The detection limit was 5.58 × 10−8 mol L−1 of H2O2. The effect of interferences was studied. The proposed method was successfully applied to the determination of hydrogen peroxide in rainwater, serum and plant samples.
Co-reporter:Bo Tang, Xu Wang, Guangli Wang, Chengguang Yu, Zhenzhen Chen
Talanta 2006 Volume 69(Issue 1) pp:113-120
Publication Date(Web):15 March 2006
DOI:10.1016/j.talanta.2005.09.007
An indirect spectrofluorimetric method with high sensitivity and selectivity was developed for the determination of antifungal drug: tolnaftate (TNF), depending on the supramolecualr multirecognition interaction among the anionic surfactant sodium laurylsulfate (SLS), β-cyclodextrin (β-CD) and β-naphthol (ROH). The mechanism of the inclusion was studied and discussed by means of fluorescence spectrum, infra-red spectrograms and 1HNMR spectroscopy. Results showed that the naphthalene ring of ROH and the hydrophobic hydrocarbon chain of SLS were included into the β-CD's cavity to form a ROH:SLS:β-CD ternary inclusion complex with stoichiometry of 1:1:1 at room temperature, which provided effective protection for the excited state of ROH. At λex/λem = 273/360 nm, the fluorescence intensity was linear over a tolnaftate concentration range of 2.46 × 10−9 to 2.10 × 10−6 mol L−1. The detection limit and relative standard deviation was 7.50 × 10−10 mol L−1 and 1.4%, respectively. The interference of 31 foreign substances was slight. The proposed method had been successfully applied to the determination of tolnaftate in artificial mixed samples with almost quantitative recovery.
Co-reporter:Kehua Xu, Bo Tang, Hui Huang, Guiwen Yang, Zhenzhen Chen, Ping Li and Liguo An
Chemical Communications 2005 (Issue 48) pp:5974-5976
Publication Date(Web):08 Nov 2005
DOI:10.1039/B512440A
This paper reports the synthesis, fluorescence properties, and biological applications of naphthofluorescein disulfonate (NFDS-1), as a red fluorescence imaging probe to detect intracellular H2O2.
Co-reporter:Bo Tang, Jinye Niu, Chengguang Yu, Linhai Zhuo and Jiechao Ge
Chemical Communications 2005 (Issue 33) pp:4184-4186
Publication Date(Web):19 Jul 2005
DOI:10.1039/B502978C
Highly luminescent water-soluble CdTe nanowires synthesized in one step were used to detect copper(II) selectively below 0.078 µM in the presence of other physiologically relevant cations.
Co-reporter:Bo Tang, Linhai Zhuo, Jiechao Ge, Guangli Wang, Zhiqiang Shi and Jinye Niu
Chemical Communications 2005 (Issue 28) pp:3565-3567
Publication Date(Web):09 Jun 2005
DOI:10.1039/B500708A
A surfactant-free route was successfully established to synthesize CeO2 single-crystalline nanowires using H2O2 as oxidizer and template agent.
Co-reporter:Bo Tang, Xu Wang, Guangli Wang, Yan Wang and Zhenzhen Chen
Analyst 2005 vol. 130(Issue 7) pp:1038-1045
Publication Date(Web):09 Jun 2005
DOI:10.1039/B503217B
A strong and stable room temperature phosphorescence (RTP) signal (λex/λem
= 298/481 nm) resulting from a 1 ∶ 1 ∶ 1 β-cyclodextrin (β-CD)/thiabendazole (TBZ)/triton X-100 (TX-100) supramolecular ternary inclusion complex was induced by KI as a heavy atom perturber. Based on the heavy-atom induced RTP, a new phosphorescence method for TBZ determination was established. The analytical curve of TBZ gave a linear range of 20–820 ng mL−1 with a detection limit and relative standard deviation of 2.1 ng mL−1 and 1.9%, respectively. The interference of 46 coexisting substances was studied. Compared with the method using a chemical oxygen scavenger, this method is simpler as deoxygenation of the solution is not required. The detection limit and the heavy-atom concentration of the proposed method were decreased about 8 and 4 times, respectively. The lifetime of the phosphorescence was prolonged 9 times and the pH range was greatly broadened. The proposed method has been successfully applied to the determination of TBZ in tap water, lake water and pineapples.
Co-reporter:Bo Tang, Li Zhang, Yue Geng
Talanta 2005 Volume 65(Issue 3) pp:769-775
Publication Date(Web):15 February 2005
DOI:10.1016/j.talanta.2004.08.004
This paper presents an automatic spectrofluorimetric method (flow injection analysis spectrofluorimetry) for detecting hydroxyl radicals. Based on H2O2 catalyzed by Co2+ yielding HO, the method utilized sodium terephthalate to trap hydroxyl radicals and obtained sodium 2-hydroxyterephthalate by aromatic hydroxylation, which resulted in an increase in the fluorescence intensity. The relative fluorescence intensity was proportional to the concentration of hydroxyl radicals. Hydroxyl radicals could be determined indirectly, based on the increase of fluorescence. It was a simple, rapid, precise, sensitive and automatic technique for the determination of HO. The relative standard deviation of 11 determinations was 0.57%. The method can be used to sieve antioxidant medicines and will have theoretical and practical guidance on the mechanism of hydroxyl radicals-damaging biology.
Co-reporter:Bo Tang, Wen-Li Liu, Yan Wang, Zhen-Zhen Chen
Analytica Chimica Acta 2004 Volume 509(Issue 2) pp:145-150
Publication Date(Web):3 May 2004
DOI:10.1016/j.aca.2003.12.037
The supramolecular interaction between N,N-diethyl-2-(1-naphthalenyloxy)propanamide (napropamide) and β-cyclodextrin (β-CD) has been studied by spectrofluorimetry. The results showed that β-CD reacted with napropamide to form an inclusion complex with an association constant of 3.18×103 l mol−1. The composition of the complex was 1:1 (β-CD:napropamide). Based on the significant enhancement of fluorescence intensity of napropamide in inclusion complex, a spetrofluorimetric method with high sensitivity and selectivity was developed for the determination of napropamide in aqueous solution. Under the optimum conditions, the complex had excitation and emission maxima at 285 and 339 nm, respectively. The linear range of the method was 3.7–1500 ng ml−1 with a detection limit of 1.1 ng ml−1. The proposed method was successfully used to determine napropamide in river water.
Co-reporter:Bo Tang, Li Zhang, Ji-Xi Hu, Ping Li, Hui Zhang, Yan-Xiu Zhao
Analytica Chimica Acta 2004 Volume 502(Issue 1) pp:125-131
Publication Date(Web):23 January 2004
DOI:10.1016/j.aca.2003.09.052
A novel spectrofluorimetric method using vanillin-8-aminoquinoline (VAQ) as fluorescent probe was developed for the determination of superoxide anion radical (O2−). The new fluorescent probe was characterized by elemental analysis and IR spectra. Under the optimum conditions of the determination, the linear calibration range and the detection limit of the developed method for superoxide anion radical were in the range (0.0–1.0)×10−5 and 2.0×10−8 mol l−1, respectively. The effect of interferences was studied. The proposed method was applied to determine the generation rate of superoxide anion radical in the course of aging in red sage successfully.
Co-reporter:Bo Tang, Taixing Yue, Junsen Wu, Yuming Dong, Yi Ding, Hongjian Wang
Talanta 2004 Volume 64(Issue 4) pp:955-960
Publication Date(Web):15 November 2004
DOI:10.1016/j.talanta.2004.04.016
A novel fluorescent reagent o-vanillin-8-aminoquinoline(OVAQ) was synthesized, and its infrared spectrum, elemental analysis and acid–base dissociation constants were obtained. The fluorescent reaction of this reagent with Cr(III) was studied. In acetonitrile–water (1:1, (v/v)) medium of pH 6.00, Cr(III) could react with fluorescent reagent OVAQ (λex/em=280/314 nm) to form a 1:1 non-fluorescent complex. The linear range of the spectrofluorimetric method proposed was from 8.2 to 130 μg l−1, and the detection limit was 2.5 μg l−1. The interferences of 25 foreign ions were also studied. This method could be easily performed and was successfully applied to the determination of Cr(III) and total chromium in domestic and industrial waste water samples.
Co-reporter:Hui Zhang, Bo Tang, Yan Wang
Talanta 2004 Volume 63(Issue 4) pp:825-831
Publication Date(Web):8 July 2004
DOI:10.1016/j.talanta.2003.12.047
A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of osmium(IV) and the possible mechanism of catalytic reaction was discussed. The method is based on the fluorescence enhancing reaction of o-vanillin furfuralhydrazone (OVFH) with potassium bromate, which was catalysed by osmium(IV) in water medium. Beta-cyclodextrin (beta-CD) obviously sensibilized the determination at pH 6.10 and 55 °C. Under optimum conditions, beta-CD–osmium(IV)–KBrO3–OVFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 337 and 490 nm, respectively. The linear range of this method was 0–120 ng ml−1 with a R.S.D. of 1.1%, and the detection limit was 0.38 ng ml−1. The effect of interferences was studied. Distillation was used to separate osmium from interfering elements in the samples. The proposed method was applied successfully to determine osmium(IV) in synthetic mixture and mineral samples, the results were well consistent with the reference standard values.
Co-reporter:Li Ma, Bo Tang, Chun Chu
Analytica Chimica Acta 2002 Volume 469(Issue 2) pp:273-283
Publication Date(Web):3 October 2002
DOI:10.1016/S0003-2670(02)00719-5
Dapsone (DDS) forms a 1:1 supramolecular complex with β-cyclodextrin (β-CD) both in the absence and presence of linear alcohols. The apparent association constants (Kapp) were measured using a steady-state fluorescence method. Kapp decreases linearly with an increasing number of carbon atoms in the chain of the alcohol. We attribute this to a competition between dapsone and linear alcohol for the β-CD hydrophobic cavity as detailed analysis of Kapp as a function of the concentration of alcohol suggests that the interactions in the β-CD–dapsone–linear alcohol system do not result in the formation of ternary supramolecular complex. Quenching the fluorescence of dapsone with NaI shows that the β-CD cavity acts as a shield against contact between dapsone and this aqueous phase quencher, while addition of alcohols inhibits this protective effect. This again suggests that alcohols occupy the space within the β-CD cavity with the result that dapsone molecules are forced to reside in the aqueous environment. Based on the significant enhancement of the fluorescence intensity of dapsone produced through complex formation, a spectrofluorimetric method for the determination of dapsone in bulk aqueous solution in the presence of β-CD is developed. The linear relationship between the fluorescence intensity and dapsone concentration was obtained in the range of 3.39 to 1.50×103 ng ml−1, with a correlation coefficient (r) of 0.9998. The detection limit was 1.02 ng ml−1. There was no interference from the excipients normally used in tablet formulations. The application of the present method to the determination of dapsone in tablets and human plasma gave satisfactory results and was compared with the pharmacopoeia method.
Co-reporter:Bo Tang, Li Ma, Chi Ma
Talanta 2002 Volume 58(Issue 5) pp:841-848
Publication Date(Web):12 November 2002
DOI:10.1016/S0039-9140(02)00400-9
The supramolecular interaction of rubidate (chemically 2,3-naphthalenedicarboxylic acid, 1,4-dihydroxy-diethyl ester) and β-cyclodextrin (β-CD) has been studied by spectrofluorimetry. The influence of temperature on the supramolecular system has also been investigated and the thermodynamic parameters were calculated. The results show that β-CD reacts with rubidate to form a 1:1 host–guest complex with an apparent association constant of 566±23 l mol−1. It was also demonstrated that the thermodynamics of β-CD–rubidate complex displayed a compensatory enthalpy–entropy relationship. Based on the significant enhancement of the fluorescence intensity of rubidate produced through complex formation, a spectrofluorimetric method for the determination of rubidate in bulk aqueous solution in the presence of β-CD was developed. The linear relationship between the fluorescence intensity and rubidate concentration was obtained in the range from 2.7×10−2 to 3.0 μg ml−1, with a correlation coefficient of 0.9988. The detection limit was 8.2 ng ml−1 and the relative standard deviation was 1.6%. There was no interference from the excipients normally used in tablet formulations. The application of the present method to the determination of rubidate in tablets gave satisfactory results and was compared with the reference method.
Co-reporter:Qiaoyan Shang, Shuqian Xia, GuanWei Cui, Bo Tang, Peisheng Ma
Fluid Phase Equilibria (15 May 2017) Volume 439() pp:
Publication Date(Web):15 May 2017
DOI:10.1016/j.fluid.2017.02.012
•The IFTs of five systems (paraffins + CO2/(CO2+N2) mixture gas) were measured.•The relative Gibbs adsorption isotherm (Γij) was calculated by the measured IFTs.•The Γij changed with temperature and pressure were studied.•New correlations of paraffins IFTs were presented based on the experimental IFTs.Interfacial tension (IFT) is crucial for characterizing the phase and interphase behavior in the enhanced oil recovery (EOR) process. CO2 and N2 are commonly used as injection gases in the EOR process. In this work, an experimental apparatus using the pendent drop method was adopted to measure IFTs for the EOR process with different injection gases, temperatures (40.0–120.0 °C) and pressures (0.22–17.32 MPa). The relative Gibbs adsorption isotherm (Γij) of a species i on species j were calculated by the experimental IFTs. Theoretically, new correlations were proposed to predict paraffin IFTs for pure CO2 and mixture gas (CO2 + N2) injection. A total of 561 and 268 experimental IFTs were used to derive the correlations for pure CO2 and mixture gas injection, respectively. The square of correlation coefficient (R2), root mean square error (RMSE) and average absolute relative deviations (AARD) for pure CO2 were 0.9884, 0.58 and 5.45%, respectively. For the mixture gas injection, the R2, RMSE and AARD of the correlation were 0.9851, 0.57 and 4.47%, respectively.The IFTs of five paraffins with different injection gases were measured by pendent drop method. The relative Gibbs adsorption isotherm (Γ12) were calculated by experimental IFTs. The new correlations present IFT as a function of reservoir temperature, pressure, paraffin chain length and N2 mole fraction. The R2, RMSE and AARD of the correlation for the pure CO2 injection were 0.9884, 0.58 and 5.45%, respectively. The R2, RMSE and AARD of the correlation for the mixture gas injection were 0.9851, 0.57 and 4.47%, respectively. LOOCV and external validation methods were used to check the reliability and accuracy of the new correlations.
Co-reporter:Haibin Xiao, Xiao Liu, Chuanchen Wu, Yaohuan Wu, Ping Li, Xiaomeng Guo, Bo Tang
Biosensors and Bioelectronics (15 May 2017) Volume 91() pp:
Publication Date(Web):15 May 2017
DOI:10.1016/j.bios.2016.12.068
•A new ER-targeted two-photon fluorescent probe for imaging of O2•− was developed.•It possessed excellent photophysical properties and ER-targeted ability.•The imaging of O2•− in live cells under different ER-stress stimuli was achieved.•The O2•− level difference in normal/diabetic mice was visualized.Excessive or unfolded proteins accumulation in endoplasmic reticulum (ER) will cause ER stress, which has evolved to involve in various metabolic diseases. In particular, ER stress plays an important role in the pathogenesis of diabetes. Both ER stress and course of diabetes accompany oxidative stress and production of reactive oxygen species (ROS), among which superoxide anion (O2•−) is the first produced ROS and has been recognized as cell signaling mediator involved in the physiological and pathological process of diabetes. Hence, the development of effective monitoring methods of O2•− in live cells and in vivo is of great importance for ascertaining the onset and progress of related diseases. Herein, a new endoplasmic reticulum-targeted two-photon fluorescent probe termed ER-BZT is designed and synthesized for imaging of O2•−. The probe ER-BZT shows high sensitivity, selectivity, stability, and low cytotoxicity. Based on these superior properties, the rise of O2•− levels in endoplasmic reticulum induced with different stimuli is visualized by one- and two-photon fluorescence imaging. Most importantly, by utilizing ER-BZT, the two-photon fluorescence imaging results demonstrate that the endogenous O2•− concentration in abdominal or hepatic tissue of diabetic mice is higher than that in normal mice. Meanwhile, after treated with metformin, a broad-spectrum antidiabetic drug, the diabetic mice exhibit depressed O2•− level. The proposed two-photon probe, ER-BZT might serve as perfect tool to image the O2•− fluctuations and study the relevance between O2•− and various diseases in live cells and in vivo.
Co-reporter:Wen Gao, Kehua Xu, Lifei Ji, Bo Tang
Toxicology Letters (10 August 2011) Volume 205(Issue 1) pp:86-95
Publication Date(Web):10 August 2011
DOI:10.1016/j.toxlet.2011.05.1018
Gold nanoparticles (AuNPs) have shown promising biological and military applications due to their unique electronic and optical properties. However, little is known about their cytotoxicity when they come into contact with a biological system. The primary objective of this study is to determine the sequence of apoptotic signaling events that occur after modulation of the cellular redox state in HL7702 cells (human liver cell line), with emphasis on the role of the interaction of AuNPs with glutathione (GSH). After incubation with 8 nm AuNPs at 50 nM, there was an early decline in cytosolic GSH, which initiated mitochondrial transmembrane potential (ΔΨm) depolarization and apoptosis. Mitochondrial GSH depletion was observed at approximately 48 h, after which mitochondrial hydrogen peroxide (H2O2) production increased significantly and apoptosis was further exacerbated. Bax translocation, cytochrome c release and downstream caspase 3 were first detected at 24 h, notably after 48 h, corresponding with increasing H2O2 level. These data suggest that HL7702 cells are depleted of intracellular GSH as a result that 8 nm AuNPs possess strong Au–S bonding interactions with GSH. A decrease in GSH alone can act as a potent early activator of apoptotic signaling. Increased H2O2 production following mitochondrial GSH depletion represents a crucial event, which commits HL7702 cells to apoptosis through mitochondrial pathway.Highlights► The mechanism for GSH depletion induced by gold nanoparticles in human liver cells (HL7702). ► Cytosolic and mitochondrial GSH depletion in HL7702 cells following 8 nm gold nanoparticles treatment. ► H2O2 generation increased significantly following the depletion of mitochondrial GSH. ► The sequence of mitochondrial signaling events in 8 nm gold nanoparticles-induced apoptosis.
Co-reporter:Junfeng Xie, Jianping Xin, Guanwei Cui, Xinxia Zhang, Lijie Zhou, Yunlong Wang, Weiwei Liu, Caihua Wang, Mei Ning, Xinyuan Xia, Yingqiang Zhao and Bo Tang
Inorganic Chemistry Frontiers 2016 - vol. 3(Issue 9) pp:NaN1166-1166
Publication Date(Web):2016/07/19
DOI:10.1039/C6QI00198J
The catalytic activity of an electrocatalyst is determined by the density of active sites and the electric conductivity, namely, the density of electrically connected active sites. In this work, elemental incorporation, disorder engineering and material hybridization were applied to molybdenum disulfide (MoS2) simultaneously to realize a high-level synergistic optimization for both active sites and electric conductivity, achieving highly efficient hydrogen-evolving performance finally. Benefitting from the synergistic optimization, the vertically aligned oxygen-doped MoS2/carbon cloth catalyst shows an ultralow onset overpotential of 90 mV to initiate the HER process, and an extremely high catalytic current of 225 mA cm−2 was measured at an overpotential of 300 mV. Not only that, superior stability was also achieved, making this novel catalyst promising for practical applications such as electrolytic water splitting and a co-catalyst for photocatalytic/photoelectrochemical hydrogen production. The synergistic optimization strategy reported in this work would shed light on the systematic design of highly efficient electrocatalysts in the future.
Co-reporter:Kehua Xu, Mingming Qiang, Wen Gao, Ruixian Su, Na Li, Yan Gao, Yanxia Xie, Fanpeng Kong and Bo Tang
Chemical Science (2010-Present) 2013 - vol. 4(Issue 3) pp:NaN1086-1086
Publication Date(Web):2012/12/14
DOI:10.1039/C2SC22076H
Alterations of cellular redox status are closely associated with physiological and pathological processes. Glutathione (GSH) and H2O2 should be the most representative redox couple in living cells. However, up to now, there is no way to reversibly detect GSH/H2O2. In this report, a near-infrared (NIR) fluorescent probe (Cy-O-Eb) for monitoring the changes of GSH/H2O2 levels in vivo was developed based on switching on–off a five-membered ring involved in ebselen. This probe could reversibly respond to GSH and H2O2 with high selectivity, sensitivity and mitochondrial targeting. It was successfully used to monitor the changes of redox status during apoptosis and the H2O2 changes at the wound margin in zebrafish larvae. Thus, the probe would provide an ideal tool for monitoring redox status changes and studying molecular events involved in redox regulation.
Co-reporter:Xilei Xie, Fuyan Tang, Xiaoyan Shangguan, Shiyi Che, Jinye Niu, Yongsheng Xiao, Xu Wang and Bo Tang
Chemical Communications 2017 - vol. 53(Issue 48) pp:NaN6523-6523
Publication Date(Web):2017/05/22
DOI:10.1039/C7CC03050A
Lyso-TPFP presents lysosomal targetability and an acidic pH-activatable response toward formaldehyde. Thus, it exclusively visualizes lysosomal formaldehyde and is immune against it in neutral cytosol and other organelles. In addition, two-photon fluorescence imaging endows Lyso-TPFP with the capability of in situ tracking formaldehyde in live cells and animals.
Co-reporter:Na Li, Yanli Li, Xiaonan Gao, Zhengze Yu, Wei Pan and Bo Tang
Chemical Communications 2017 - vol. 53(Issue 36) pp:NaN4965-4965
Publication Date(Web):2017/04/03
DOI:10.1039/C7CC00822H
We demonstrate a novel DNAzymes-based nanocomposite that can simultaneously silence three types of genes in living cells and in vivo. The synergetic strategy for silencing three different genes can significantly enhance the knockdown efficacy and effectively inhibit the cancer cells’ progression.
Co-reporter:Mingming Luan, Na Li, Wei Pan, Limin Yang, Zhengze Yu and Bo Tang
Chemical Communications 2017 - vol. 53(Issue 2) pp:NaN359-359
Publication Date(Web):2016/11/23
DOI:10.1039/C6CC07605J
We develop a multicolor fluorescent nanoprobe for assessing cellular migration and invasion by simultaneously imaging miRNA-221, PTEN mRNA and MMP-9 involved in the PI3K/AKT pathway which can regulate cellular mobility and invasiveness.
Co-reporter:Yong Li, Xilei Xie, Xiu’e Yang, Mengmeng Li, Xiaoyun Jiao, Yuhui Sun, Xu Wang and Bo Tang
Chemical Science (2010-Present) 2017 - vol. 8(Issue 5) pp:NaN4011-4011
Publication Date(Web):2017/03/20
DOI:10.1039/C7SC00303J
Drug-induced injury has attracted increasing attention in public health issues. Among them, hepatotoxicity has been regarded as the leading clinical problem caused by drug toxicity. However, owing to the complexity of the involved pathophysiological mechanisms and the lack of noninvasive, straightforward, and real-time tools, drug-induced hepatotoxicity has rarely been predicted satisfactorily. In this paper, by utilizing the reactive species peroxynitrite (ONOO−) as a biomarker, we present a two-photon fluorescent probe, TP-KA, holding rapid response, high specificity and sensitivity towards ONOO−, to investigate drug (acetaminophen and tolcapone)-related liver injury and the remediate effect of N-acetyl cysteine (NAC). With the support of TP-KA, we obtained direct and visual evidence of the upregulation of ONOO− during drug challenge both in live cells and mice, which was accompanied by liver tissue injury and tyrosine nitration. These findings demonstrate that ONOO− is a good and appropriate biomarker of hepatotoxicity, and nitrosative stress may be necessary for acetaminophen and tolcapone to exert their toxicity. Moreover, TP-KA can be employed as a powerful tool to pre-detect drug-induced organism injury and study the effect of antidotes.
Co-reporter:Li-juan Wang, Fei Ma, Bo Tang and Chun-yang Zhang
Chemical Science (2010-Present) 2017 - vol. 8(Issue 4) pp:NaN2502-2502
Publication Date(Web):2016/12/13
DOI:10.1039/C6SC04801C
Telomerase is a ribonucleoprotein reverse transcriptase that is responsible for maintaining the telomere length in cells. Telomerase overexpresses in almost all malignant tumor cells, and it has become a promising biomarker and a potential therapy target for cancers. Consequently, accurate and efficient quantification of the telomerase is highly essential to medical diagnostics and therapeutics. Recently, a series of novel telomerase detection methods with excellent performance have been developed, but a overview of in vivo telomerase detection methods is lacking. In this Minireview, we summarize the emerging strategies for telomerase assays in the last five years, including both in vitro assays and in vivo imaging methods, and discuss their future directions as well.
Co-reporter:Ping Li, Ting Xie, Nannan Fan, Kexiang Li and Bo Tang
Chemical Communications 2012 - vol. 48(Issue 15) pp:NaN2079-2079
Publication Date(Web):2011/11/07
DOI:10.1039/C1CC15258K
We devised a new ratiometric fluorescent probe for the detection of chloride ions. This synthesized probe was applied to the ventricular myocytes to successfully realize dynamic imaging of Cl− concentration fluctuations during the myocardial ischemia course.
Co-reporter:Wei Zhang, Junqing Kang, Ping Li, Lu Liu, Hui Wang and Bo Tang
Chemical Communications 2016 - vol. 52(Issue 97) pp:NaN13994-13994
Publication Date(Web):2016/10/31
DOI:10.1039/C6CC08211D
We have designed and synthesized a sialic acid (SA)-imprinted conjugated polymer nanoprobe with two-photon fluorescence properties, which exhibits specific recognition ability to the target SA and has been used for monitoring sialylated glycan levels selectively in vivo.
Co-reporter:Haibin Xiao, Ping Li, Shan Zhang, Wei Zhang, Wen Zhang and Bo Tang
Chemical Communications 2016 - vol. 52(Issue 86) pp:NaN12744-12744
Publication Date(Web):2016/10/03
DOI:10.1039/C6CC07182A
We report simultaneous fluorescence imaging of hydrogen peroxide and zinc ions within mitochondria using two fluorescent probes termed M-H2O2 and M-Zn.
Co-reporter:Yan Zhang, Yueying Li, Bo Tang and Chun-yang Zhang
Chemical Communications 2017 - vol. 53(Issue 52) pp:NaN6998-6998
Publication Date(Web):2017/05/23
DOI:10.1039/C7CC00901A
SUMOylation is a post-translational modification that plays critical roles in a multitude of cellular processes including transcription, cellular localization, DNA repair and cell cycle progression. Similar to ubiquitin, the small ubiquitin-like modifiers (SUMOs) are covalently attached to the epsilon amino group of lysine residues in the substrates. To understand the regulation and the dynamics of post-translational modifications (PTMs), the identification and quantification of SUMOylation is strictly needed. Although numerous proteomic approaches have been developed to identify hundreds of SUMO target proteins, the number of SUMOylation signatures identified from endogenous modified proteins is limited, and the identification of precise acceptor sites remains a challenge due to the low abundance of in vivo SUMO-modified proteins and the high activity of SUMO-specific proteases in cell lysates. In particular, very few sensitive strategies are available for accurate quantification of SUMO target proteins. Within the past decade, mass spectrometry-based strategies have been the most popular technologies for proteome-wide studies of SUMOylation. Recently, some new approaches such as single-molecule detection have been introduced. In this review, we summarize the strategies that have been exploited for enrichment, purification and identification of SUMOylation substrates and acceptor sites as well as ultrasensitive quantification of SUMOylation. We highlight the emerging trends in this field as well.
Co-reporter:Ran Wang, Gang Li, Andong Zhang, Wen Wang, Guanwei Cui, Jianfeng Zhao, Zhiqiang Shi and Bo Tang
Chemical Communications 2017 - vol. 53(Issue 51) pp:NaN6921-6921
Publication Date(Web):2017/06/05
DOI:10.1039/C7CC03682E
We design and synthesize four pyran-embedded perylene diimide (PDI) compounds through a straightforward methodology. UV-driven photocatalytic water splitting using the compounds as photocatalysts demonstrates that the highest photocatalytic H2 evolution rate under UV light is 0.90 mmol g−1 h−1, which paves the way towards organic photoresponsive materials.
Co-reporter:Li-Juan Wang, Zi-Yue Wang, Qianyi Zhang, Bo Tang and Chun-Yang Zhang
Chemical Communications 2017 - vol. 53(Issue 27) pp:NaN3881-3881
Publication Date(Web):2017/03/13
DOI:10.1039/C7CC00946A
We develop a new fluorescence method for real-time monitoring of thymine DNA glycosylase (TDG) activity through cyclic enzymatic repairing-mediated dual-signal amplification. This method exhibits excellent sensitivity with a detection limit of 5.6 × 10−7 U μL−1, and it can be used to determine kinetic parameters and quantify TDG activity from even single cancer cells.
Co-reporter:Zhenhua Liu, Huimin Ji, Wen Gao, Guangyu Zhu, Lili Tong, Fengcai Lei and Bo Tang
Chemical Communications 2017 - vol. 53(Issue 46) pp:NaN6262-6262
Publication Date(Web):2017/05/18
DOI:10.1039/C7CC02391J
A copper(I)-mediated carboamination cascade reaction between vinyl azides and aryldiazonium salts is described. Functionally diverse N2-substituted 1,2,3-triazoles were obtained in moderate to good yields through novel difunctionalization of vinyl azides by aryldiazonium salt sources. This method has a wide scope, good functional-group tolerance and insensitivity to an ambient atmosphere.
Co-reporter:Fei Ma, Wen-jing Liu, Bo Tang and Chun-yang Zhang
Chemical Communications 2017 - vol. 53(Issue 51) pp:NaN6871-6871
Publication Date(Web):2017/06/06
DOI:10.1039/C7CC03736H
We develop a single quantum dot (QD)-based nanosensor for the signal-on detection of DNA methyltransferase (MTase). By integration of single-molecule counting with the QD-based fluorescence resonance energy transfer (FRET), the proposed nanosensor can sensitively detect DNA MTase with a detection limit of as low as 0.002 U mL−1, and it can be further applied for inhibitor screening and accurate detection of DNA MTase in complex biological samples.
Co-reporter:Ping Li, Haibin Xiao, Yinfang Cheng, Wen Zhang, Fang Huang, Wei Zhang, Hui Wang and Bo Tang
Chemical Communications 2014 - vol. 50(Issue 54) pp:NaN7187-7187
Publication Date(Web):2014/05/15
DOI:10.1039/C4CC01390E
We demonstrate a new small molecule fluorescent probe, possessing near-infrared (NIR) emission and an unusually large Stokes shift. It can be readily taken up by live cells and mitochondria, and track subtle pH changes with effectively reduced biological background fluorescence and improved measurement accuracy.
Co-reporter:Na Li, Huijun Yang, Zhengze Yu, Yanli Li, Wei Pan, Hongyu Wang and Bo Tang
Chemical Science (2010-Present) 2017 - vol. 8(Issue 4) pp:NaN2822-2822
Publication Date(Web):2017/01/19
DOI:10.1039/C6SC04293G
Developing effective nonviral siRNA delivery systems for long-term gene silencing remains a great challenge. Here we present a nuclear-targeted siRNA delivery system that can induce long-term gene silencing in cancer cells. The nanocarrier consists of gold nanoparticles modified with a dense shell of synthetic siRNAs and nuclear localization signal (NLS) peptides. The NLS peptide could translocate the nanocarrier into the nucleus and the siRNA was designed to target the promoter of thymidine kinase 1 and trigger the RNA-directed DNA methylation, thereby enabling the nuclear-targeted gene silencing. Compared with traditional gene silencing in cytoplasm, long-lasting gene knockdown could be achieved for the nuclear-targeted nanocarrier, which lasts for more than 30 days. The long-term gene silencing induced by nuclear-targeted siRNA delivery could effectively inhibit the proliferation of cancer cells and prevent the formation of a tumor in a mouse model.
Co-reporter:Zhengze Yu, Meimei Wang, Wei Pan, Hongyu Wang, Na Li and Bo Tang
Chemical Science (2010-Present) 2017 - vol. 8(Issue 7) pp:NaN4903-4903
Publication Date(Web):2017/05/02
DOI:10.1039/C7SC00700K
Nanoparticles as novel theranostic agents for cancer treatment have been extensively investigated in recent years. However, the poor tumor selectivity and retention of the theranostic agents result in unsatisfactory performance of both the diagnostic and therapeutic functions. Herein, we developed an alpha-cyclodextrin (α-CD)-based gold/DNA nanomachine for tumor-selective diagnosis and therapy. The α-CDs were capped at the ends of DNA, and their release was triggered by the low pH of the tumor microenvironment, which further resulted in DNA self-assembly through complementary base pairing. The large-sized gold aggregates failed to escape from the tumor tissue, thereby realizing the goal of tumor-specific targeting and enhanced retention. Thus, the photoacoustic signal and photothermal effect are also activated, thereby achieving tumor-targeted photoacoustic imaging and photothermal therapy. In vivo results indicated that the designed gold nanomachines can serve as efficient theranostic agents for diagnosis and therapy. Moreover, we found that the α-CD caps have the ability to protect the nanoparticles from clearance and enzyme digestion, which helps the nanoparticles reach the tumor more efficiently.
Co-reporter:Yan Zhang, Fei Ma, Bo Tang and Chun-yang Zhang
Chemical Communications 2016 - vol. 52(Issue 26) pp:NaN4748-4748
Publication Date(Web):2016/02/18
DOI:10.1039/C5CC09891B
Transcription factors (TFs) play central roles in the regulation of gene expression through binding to specific DNA sequences, and may influence multiple transcription-associated cellular processes including cell development, differentiation, and growth. Alterations in TF levels may lead to a variety of human diseases. Consequently, rapid and sensitive detection of TFs is crucial to both biological research and clinical diagnostics. However, conventional methods for TF assays are usually laborious and time-consuming with poor sensitivity, and sometimes involve the radioactive materials. To overcome these limitations, some new approaches have been developed with a low detection limit, high specificity, high throughput, and low cost. In this paper, we review the recent advances in TF assays and highlight the emerging trends as well.
Co-reporter:Xinyuan Xia, Ning Deng, Guanwei Cui, Junfeng Xie, Xifeng Shi, Yingqiang Zhao, Qian Wang, Wen Wang and Bo Tang
Chemical Communications 2015 - vol. 51(Issue 54) pp:NaN10902-10902
Publication Date(Web):2015/05/27
DOI:10.1039/C5CC02589C
NIR light induced H2 evolution was realized by metal-free photocatalysis for the first time. The considerable H2 production at 808 nm and large promotion of the photocatalytic activity in both UV-Vis and Vis regions originated from the synergistic effect on spectral and electronic coupling of g-C3N4 nanosheets and carbon quantum dots.
Co-reporter:Wen Gao, Xueping Wei, Xuejun Wang, Guanwei Cui, Zhenhua Liu and Bo Tang
Chemical Communications 2016 - vol. 52(Issue 18) pp:NaN3646-3646
Publication Date(Web):2016/02/05
DOI:10.1039/C6CC00112B
A competitive coordination-based hydrogen peroxide (H2O2) nanosensor is constructed by the assembly of FAM-tagged single-strand (ss) DNA on cerium oxide nanowires (CeO2 NWs). This fluorescent nanosensor is capable of rapidly and selectively tracking H2O2 within living cells, as well as directly visualizing H2O2 generated by wound-induced oxidative damage in zebrafish larvae.
Co-reporter:Xiaojun Liu, Bo Hu, Ranran Cheng, Fanpeng Kong, Xiaohong Pan, Kehua Xu and Bo Tang
Chemical Communications 2016 - vol. 52(Issue 40) pp:NaN6696-6696
Publication Date(Web):2016/04/19
DOI:10.1039/C6CC02111E
Based on the rapid substitution reaction of the Au–S bond by selenol, we designed and synthesized a nanoprobe 5-FAM-peptide-AuNPs for selenol. Real-time imaging shows that this probe together with the molecular probe QCy7-H2O2 is able to simultaneously and differentially monitor the concentrations of selenol and H2O2 in living cells and in vivo.
Co-reporter:Bo Tang, Xia Liu, Kehua Xu, Hui Huang, Guiwen Yang and Liguo An
Chemical Communications 2007(Issue 36) pp:NaN3728-3728
Publication Date(Web):2007/07/09
DOI:10.1039/B707173F
A dual near-infrared pH fluorescent probe has been designed, synthesized and applied to HepG2 cells, with a pKa value of 5.14 under acidic conditions and 11.31 under basic conditions, which is valuable for studying acidic organelles in living cells and pH changes in chemical systems.
Co-reporter:Fanpeng Kong, Bo Hu, Yan Gao, Kehua Xu, Xiaohong Pan, Fang Huang, Qiuling Zheng, Hao Chen and Bo Tang
Chemical Communications 2015 - vol. 51(Issue 15) pp:NaN3105-3105
Publication Date(Web):2015/01/09
DOI:10.1039/C4CC06359G
A novel fluorescence probe (HB) has been designed and synthesized to image selenol in living cells and in vivo for the first time, and used to investigate the Na2SeO3 anticancer mechanism in HepG2 cells.
Co-reporter:Lu Li, Xiuli Wang, Qingling Li, Pengyuan Liu, Kehua Xu, Hao Chen and Bo Tang
Chemical Communications 2015 - vol. 51(Issue 56) pp:NaN11320-11320
Publication Date(Web):2015/06/02
DOI:10.1039/C5CC03157E
A novel accurate method was developed for simultaneous quantitative comparison of GSH, Cys and Hcy in normal cells and cancer cells using new NPSP isotope probes based on LC/ESI-MS.
Co-reporter:Wei Pan, Yanli Li, Meimei Wang, Huijun Yang, Na Li and Bo Tang
Chemical Communications 2016 - vol. 52(Issue 24) pp:NaN4572-4572
Publication Date(Web):2016/03/01
DOI:10.1039/C5CC10147F
We demonstrate a novel strategy using FRET-based nanoprobes for the simultaneous detection of multiple mRNAs with single wavelength excitation in living cells.
Co-reporter:Feng Li, Yan Feng, Shufeng Liu and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 22) pp:NaN6349-6349
Publication Date(Web):2011/05/06
DOI:10.1039/C1CC11858G
The cleavage activity of a nicking endonuclease towards metal-ion-mediated duplex-like DNA can be triggered by the corresponding metal ions, which was demonstrated with mercuric(II) ion as a model via a simple electrochemical protocol.
Co-reporter:Feng Li, Yan Feng, Can Zhao and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 43) pp:NaN11911-11911
Publication Date(Web):2011/10/05
DOI:10.1039/C1CC15023E
A sensitive and selective amperometric sensing platform for lead (Pb2+) was developed based on a Pb2+-induced G-rich DNA conformational switch from a random-coil to G-quadruplex (G4) with crystal violet as the G4-binding indicator.
Co-reporter:Kehua Xu, Lulu Wang, Mingming Qiang, Liyong Wang, Ping Li and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 26) pp:NaN7388-7388
Publication Date(Web):2011/05/31
DOI:10.1039/C1CC12473K
A selective near-infrared fluorescent probe (His–Cy), which features a fast response to 1O2 with high sensitivity and selectivity, was designed, synthesized and applied to bioimaging.
Co-reporter:Guangming Qiao, Linhai Zhuo, Yuan Gao, Lijuan Yu, Na Li and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 26) pp:NaN7460-7460
Publication Date(Web):2011/05/17
DOI:10.1039/C1CC11490E
We demonstrate a tumor mRNA-dependent drug carrier for controlled release of doxorubicin (Dox) and intracellular imaging based on gold nanoparticle–molecular beacon. Fluorescent Dox is released effectively and induces apoptosis in breast cancer cells but not in normal cells. Significantly, the release of Dox is correlated positively with the quantities of tumor mRNA, which is according to various stages of tumor progression, and so can decrease effectively side effects of Dox.
Co-reporter:Xuan Kuang, Yu Ma, Caiyun Zhang, Hao Su, Jine Zhang and Bo Tang
Chemical Communications 2015 - vol. 51(Issue 27) pp:NaN5958-5958
Publication Date(Web):2015/02/25
DOI:10.1039/C5CC00733J
We describe for the first time a convenient technique to prepare helical CdS nanotubes, with a MOF as the template. The prepared helical CdS nanotubes were remarkably sensitive to D/L-aspartic acid (Asp) and can be used as a potential sensor for enantioselective recognition of D/L-Asp.
Co-reporter:Fanpeng Kong, Xiaoyue Meng, Ranran Chu, Kehua Xu and Bo Tang
Chemical Communications 2015 - vol. 51(Issue 32) pp:NaN6927-6927
Publication Date(Web):2015/03/12
DOI:10.1039/C5CC01130B
Based on a unique elimination reaction prompted by the iodide ion, a novel turn-on fluorescence probe (HCy-OMe-Br) has been developed for the first time. The probe emits in the near infrared region with a large Stokes shift, and can respond rapidly to iodide with high selectivity and sensitivity.
Co-reporter:Wen Zhang, Xin Wang, Ping Li, Fang Huang, Hui Wang, Wei Zhang and Bo Tang
Chemical Communications 2015 - vol. 51(Issue 47) pp:NaN9713-9713
Publication Date(Web):2015/05/06
DOI:10.1039/C5CC01670C
We report a new reversible fluorescent two-photon (TP) probe (PY-CA) with high TP absorption cross section and pH-independent fluorescence response, which allow monitoring of O2˙− fluxes dynamically, selectively and sensitively. The imaging results indicate that O2˙− at high levels can shorten the life of Caenorhabditis elegans.
Co-reporter:Wei Zhang, Wei Liu, Ping Li, Junqing kang, Jiaoyang Wang, Hui Wang and Bo Tang
Chemical Communications 2015 - vol. 51(Issue 50) pp:NaN10153-10153
Publication Date(Web):2015/05/12
DOI:10.1039/C5CC02537K
Herein, we have developed a novel reversible two-photon fluorescent probe that is well suited for monitoring HOCl levels selectively and instantaneously. Results showed the reversible and instantaneous responses of the probe towards intracellular HOCl. Moreover, the probe was successfully applied to the imaging of the HOCl levels in zebrafish and mice via two-photon imaging.
Co-reporter:Zhengze Yu, Na Li, Peipei Zheng, Wei Pan and Bo Tang
Chemical Communications 2014 - vol. 50(Issue 26) pp:NaN3497-3497
Publication Date(Web):2014/02/10
DOI:10.1039/C3CC49183H
We report a novel strategy to construct temperature-responsive nanocarriers for controlled release based on mesoporous silica and reversible single-stranded DNA valves.
Co-reporter:Hongyan Zhang, Yanhong Wang, Qingling Li, Fumiao Zhang and Bo Tang
Chemical Communications 2014 - vol. 50(Issue 53) pp:NaN7027-7027
Publication Date(Web):2014/05/07
DOI:10.1039/C4CC02342K
Using anti-EpCAM antibody modified magnetic microbeads allowed us to simultaneously apply size-amplification and magnetic labelling of CTCs to the capture and purification of CTCs by membrane filtration and immune-magnetic separation. High purity capture (>98%), rapid (<2 hours) and simple detection of CTCs were realized.
Co-reporter:Fanpeng Kong, Renpu Liu, Ranran Chu, Xu Wang, Kehua Xu and Bo Tang
Chemical Communications 2013 - vol. 49(Issue 80) pp:NaN9178-9178
Publication Date(Web):2013/08/07
DOI:10.1039/C3CC45519J
A near-infrared fluorescent probe (Cy–O–CHO) for the detection of endogenous Cys/Hcy in living cells was designed and synthesized. Cy–O–CHO exhibited high sensitivity and good selectivity to Cys/Hcy under physiological conditions with a detection limit of 7.9 nM for Cys.
Co-reporter:Wen Gao, Wenhua Cao, Huaibin Zhang, Ping Li, Kehua Xu and Bo Tang
Chemical Communications 2014 - vol. 50(Issue 60) pp:NaN8120-8120
Publication Date(Web):2014/06/05
DOI:10.1039/C4CC03793F
We have developed multifunctional Au–ZnO hybrid nanoparticles (NPs) for targeted induction lysosomal membrane permeabilization (LMP)-dependent apoptosis in cancer cells and real-time imaging.
Co-reporter:Xu Wang, Jianzheng Lv, Xueying Yao, Yong Li, Fang Huang, Mengmeng Li, Jie Yang, Xiuyun Ruan and Bo Tang
Chemical Communications 2014 - vol. 50(Issue 97) pp:NaN15442-15442
Publication Date(Web):2014/10/16
DOI:10.1039/C4CC06637E
Here we report the synthesis and screening of Cy-3-NO2 that showed simultaneous fluorescence sensing ability towards glutathione and cysteine under single excitation, and its application in living cell imaging.
Co-reporter:Yuan Gao, Guangming Qiao, Linhai Zhuo, Na Li, Ying Liu and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 18) pp:NaN5318-5318
Publication Date(Web):2011/03/31
DOI:10.1039/C1CC10557D
A bi-photosensitizer molecular beacon (bi-PS MB) is assembled by coupling two PS molecules, respectively, onto the opposite ends of a single MB. The MB can be triggered by a tumor marker-survivin mRNA. Fluorescence and cytotoxic 1O2 generation occur effectively in breast cancer cells, but not in normal cells. Compared with a single-PS MB, a bi-PS MB exhibits much-enhanced properties in the signal-to-background ratio and 1O2 generation simultaneously.
Co-reporter:Xuan Kuang, Sujuan Ye, Xiangyuan Li, Yu Ma, Caiyun Zhang and Bo Tang
Chemical Communications 2016 - vol. 52(Issue 31) pp:NaN5435-5435
Publication Date(Web):2016/03/24
DOI:10.1039/C6CC00320F
For the first time, we report the synthesis of Ag nanoparticles (NPs) arranged in a helical structure on a chiral metal–organic framework via a facile process at room temperature. This material can serve as a new type of surface-enhanced Raman scattering sensor for the efficient recognition of D/L-cysteine and D/L-asparagine enantiomers.
Co-reporter:Sujuan Ye, Yanying Wu, Wen Zhang, Na Li and Bo Tang
Chemical Communications 2014 - vol. 50(Issue 66) pp:NaN9412-9412
Publication Date(Web):2014/07/01
DOI:10.1039/C4CC03988B
A novel surface-enhanced Raman scattering (SERS) detection system is developed for proteins and nucleic acids based on a triple-helix molecular switch for multiple cycle signal amplification, achieving high sensitivity, universality, rapid analysis, and high selectivity.
Co-reporter:Jie Ding, Xia Kong, Jing Yao, Jian Wang, Xiaoguang Cheng, Bo Tang and Zhiwei He
Journal of Materials Chemistry A 2012 - vol. 22(Issue 37) pp:NaN19931-19931
Publication Date(Web):2012/08/07
DOI:10.1039/C2JM32271D
(−)-Epigallocatechin-3-gallate (EGCG) is an effective anticancer drug for a variety of cancer cell lines, but it is unstable with a half-life of 30 minutes to 2 hours under different culture conditions for cell apoptosis; EGCG dimers, hydrogen peroxide (H2O2) and other oxidative products are formed. Herein, we report that a multiple core–shell functionalized colloidal mesoporous silica nanoparticle system (CMS) resulted in the electrostatic attraction of EGCG to the surface and pores, alleviating the interaction of free radicals which produced dimers or other polymers. Based on the results of MTT assay, cell cycle analysis and western blot, the loading of EGCG into the CMS increased the anticancer ability of EGCG compared to that of free EGCG being used to treat HeLa cells in the absence of CMS. In addition, fluorescein isothiocyanate (FITC) was entrapped in the core of CMS, which allowed the CMS to simultaneously denote the position of EGCG in cells. These results demonstrate that it is possible to use the CMS platform as a promoter to improve the anticancer ability of the unstable chemotherapeutic agent.
Co-reporter:Fanpeng Kong, Lihong Ge, Xiaohong Pan, Kehua Xu, Xiaojun Liu and Bo Tang
Chemical Science (2010-Present) 2016 - vol. 7(Issue 2) pp:NaN1056-1056
Publication Date(Web):2015/10/28
DOI:10.1039/C5SC03471J
Hydrogen selenide (H2Se), a highly reactive Se species, is an important selenium metabolism intermediate involved in many physiological and pathological processes. This compound is of scientific interest with regard to the real-time monitoring of H2Se in living cells and in vivo to understand the anti-cancer mechanism of selenium. However, monitoring H2Se in living cells is still challenging due to the lack of straight forward, highly selective and rapid methods. Here, we developed a novel small-molecule fluorescent probe, NIR-H2Se, for imaging endogenous H2Se. NIR-H2Se exhibited high selectivity toward H2Se over selenocysteine (Sec), H2S and small molecule thiols and was successfully used to image the H2Se content in HepG2 cells during Na2SeO3-induced apoptosis. Increased H2Se content and reduced ROS levels were observed under hypoxic conditions compared to normoxic conditions, which indicated that the cell apoptosis induced by Na2SeO3 under a hypoxic environment is via a non-oxidative stress mechanism. Thus, this probe should serve as a powerful tool for exploring the physiological function of H2Se and Se anticancer mechanisms in a variety of physiological and pathological contexts.
Co-reporter:Haibin Xiao, Ping Li, Wei Zhang and Bo Tang
Chemical Science (2010-Present) 2016 - vol. 7(Issue 2) pp:NaN1593-1593
Publication Date(Web):2015/11/23
DOI:10.1039/C5SC04099J
Mitochondrial polarity is a crucial characteristic of these indispensable organelles, and tremendously impacts cellular events. Herein, we describe a new mitochondria-targeting fluorescent probe MCY-BF2 that is singularly sensitive and specifically responsive to mitochondrial polarity. The pull–push system in the conjugated structure of MCY-BF2 is responsible for the polarity-ultrasensitivity due to the excited state intramolecular charge transfer (ICT). By combining with cardiolipin, MCY-BF2 preferentially accumulates in mitochondria. Because the fluorescence emission wavelengths exhibit an obvious red-shift with increasing media polarity, the fluorescence intensity ratio at two different wavelengths versus the solvent dielectric constant can quantify the mitochondrial polarity. Experimental results demonstrate that the fluorescent intensity of MCY-BF2 in a non-polar solvent, dioxane, is 120 times higher than that in a polar solvent, dimethyl sulfoxide. As the first near-infrared (NIR) and most sensitive fluorescent imaging probe for polarity, MCY-BF2 can locate exclusively in mitochondria in various cells and discriminate polarity differences between normal and cancer cells. Also, the intrinsic polarity variance at different developmental stages in Caenorhabditis elegans (C. elegans) was reported here for the first time. Interestingly, the embryonic development stage has a more non-polar environment with a dielectric constant of 7.20, and in contrast the polarity at the young adult stage changes to 10.07. In addition, in vivo imaging results suggest that the tumor tissues of mice have an obviously lower polarity than that in normal tissues. Altogether, the merits of the NIR property, high sensitivity and moderate Stokes shift all greatly promote the accuracy of imaging. This probe will be a promising tool for studying biological processes and the pathological mechanism of polarity-related diseases.
Co-reporter:Lu Li, Jie Feng, Haiyun Liu, Qingling Li, Lili Tong and Bo Tang
Chemical Science (2010-Present) 2016 - vol. 7(Issue 3) pp:
Publication Date(Web):
DOI:10.1039/C5SC03909F
Co-reporter:Xu Wang, Juan Sun, Weihong Zhang, Xiaoxu Ma, Jianzheng Lv and Bo Tang
Chemical Science (2010-Present) 2013 - vol. 4(Issue 6) pp:NaN2556-2556
Publication Date(Web):2013/04/05
DOI:10.1039/C3SC50369K
We describe the design and synthesis of a cyanine-based near-infrared ratiometric fluorescent probe, HS–Cy, for H2S detection, which features rapid response, high sensitivity, and mitochondria targeting. After a rapid quenching at 780 nm by initial nucleophilic addition on the aldehyde group, HS–Cy experienced a polymethine π-electron conjugation modulation triggered by a second nucleophilic addition on the ester, releasing the cyanine fluorophore which underwent tautomerism from enol form to ketone form. Therefore, gradual emergence of a new peak at 625 nm was observed, constructing a ratiometric signal for H2S with a detection limit of 5.0–10 nM, which is the most sensitive among the reported H2S-sensing fluorescent probes. HS–Cy was proven to selectively locate into mitochondria with faster trapping kinetics towards H2S. Based on this, the endogenously generated H2S in human A549 cells was ratiometrically detected and imaged by HS–Cy.
Co-reporter:Bo Tang, Lingling Yin, Xu Wang, Zhenzhen Chen, Lili Tong and Kehua Xu
Chemical Communications 2009(Issue 35) pp:NaN5295-5295
Publication Date(Web):2009/07/28
DOI:10.1039/B909542J
A novel organoselenium fluorescent probe (Rh-Se-2), which features a high signal-to-noise ratio (up to 170-fold), fast response (5 min) and excellent immunity to interferences, was designed, synthesized and applied to bioimaging.
Co-reporter:Kehua Xu, Huachao Chen, Jiangwei Tian, Baiyu Ding, Yanxia Xie, Mingming Qiang and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 33) pp:NaN9470-9470
Publication Date(Web):2011/07/22
DOI:10.1039/C1CC12994E
BzSe-Cy is a small-molecule fluorescent probe containing Se, which can respond reversibly to changes in ONOO− or reduced ascorbate and exhibit high sensitivity and selectivity for ONOO−.
Co-reporter:Hui Xu, Qian Li, Lihua Wang, Yao He, Jiye Shi, Bo Tang and Chunhai Fan
Chemical Society Reviews 2014 - vol. 43(Issue 8) pp:NaN2661-2661
Publication Date(Web):2014/01/06
DOI:10.1039/C3CS60309A
Nanomaterials with unique optical properties have shown great promise as probes for cellular imaging. Based on these properties, a wide range of plasmonic, fluorescent and Raman probes have been designed and prepared. Nanomaterials of different sizes and shapes have also been functionalized with various types of biomolecules, such as antibodies, DNA or RNA, which are actively exploited to realize targeted imaging. In this review, we will summarize recent advances in using functional nanomaterials for imaging, primarily cellular imaging. These nanomaterials are categorized based on their conducting properties, i.e. conductors, semiconductors and insulators.
Co-reporter:Guan-wei Cui, Xi-Feng Shi, Na Li, Chongbin Wang, Yu-Bin Dong, Xu Wang and Bo Tang
Journal of Materials Chemistry A 2012 - vol. 22(Issue 24) pp:NaN11918-11918
Publication Date(Web):2012/05/01
DOI:10.1039/C2JM31549A
A novel photocatalyst, TiO2 nanotubes with the confinement of the electron donor and acceptor at the inner and outer surface, respectively, was fabricated by a universal method. The as-designed nanostructure afforded a void space separation state of electron donors and acceptors, which remarkably enhanced the photoinduced charge separation, resulting in the enhancement of the catalytic activity for the photooxidation of olefins with O2.
Co-reporter:Lei Wang, Jinhua Zhan, Weiliu Fan, Guanwei Cui, Honggang Sun, Linhai Zhuo, Xian Zhao and Bo Tang
Chemical Communications 2010 - vol. 46(Issue 46) pp:NaN8835-8835
Publication Date(Web):2010/10/18
DOI:10.1039/C0CC03660A
Microcrystalline sodium tungsten bronze nanowire bundles were obtained via a facile hydrothermal synthesis, and were applied in water purification as visible-light-driven photocatalysts for the first time.
Co-reporter:Zhengze Yu, Wei Pan, Na Li and Bo Tang
Chemical Science (2010-Present) 2016 - vol. 7(Issue 7) pp:NaN4244-4244
Publication Date(Web):2016/03/11
DOI:10.1039/C6SC00737F
Photodynamic therapy against cancer, especially multidrug resistant cancer, is limited seriously due to the efflux of photosensitizer molecules by P-glycoprotein, which leads to insufficient production of reactive oxygen species (ROS). For the purpose of abundant ROS generation and effective therapeutic response, herein, we firstly design and fabricate a nuclear targeted dual-photosensitizer for photodynamic therapy against multidrug resistant cancer. Molecule-photosensitizer Ce6 was selected and modified on the surface of core/shell structure nano-photosensitizer upconversion@TiO2 and then nuclear targeted peptides TAT were anchored for nuclear targeting. Through selective doping of rare earth elements Er and Tm, multiple ROS (˙OH, O2˙−, and 1O2) can be generated for the dual-photosensitizer and realize their functions synergistically using a single 980 nm NIR excitation. The nano-sized photosensitizer accompanied with nuclear targeting can effectively generate multiple ROS in the nucleus regardless of P-glycoprotein and directly break DNA double strands, which is considered as the most direct and serious lesion type for cytotoxic effects. Therefore, enhanced photodynamic therapy can be achieved against multidrug resistant cancer. In vitro and in vivo studies confirmed the excellent therapeutic effect of the dual-photosensitizer against cancer cells and drug-resistant cancer cells, as well as xenograft tumor models.
Co-reporter:Na Li, Huijun Yang, Wei Pan, Wei Diao and Bo Tang
Chemical Communications 2014 - vol. 50(Issue 56) pp:NaN7476-7476
Publication Date(Web):2014/05/16
DOI:10.1039/C4CC01009D
We have established a tumour marker activated nanocarrier that can respond to the intracellular mRNA, allowing multimodal cancer cell imaging and therapy.
Co-reporter:Feng Li, Peng Li, Limin Yang and Bo Tang
Chemical Communications 2012 - vol. 48(Issue 100) pp:NaN12194-12194
Publication Date(Web):2012/11/02
DOI:10.1039/C2CC36404B
A new strategy for determining the RNA endonuclease activity of mammalian argonaute2 (Ago2) protein has been developed, which combines the unique cleavage function of Ago2 protein with an RNA molecular beacon (RMB). Through the fluorescence restoration of the RMB, simple and sensitive detection of Ago2 is achieved.
Co-reporter:Haibin Xiao, Ping Li, Xiufen Hu, Xiaohui Shi, Wen Zhang and Bo Tang
Chemical Science (2010-Present) 2016 - vol. 7(Issue 9) pp:NaN6159-6159
Publication Date(Web):2016/06/01
DOI:10.1039/C6SC01793B
Cell apoptosis is a biochemical and molecular pathway essential for maintaining cellular homeostasis. It is an integrated process involving in a series of signal transduction cascades. Moreover, the apoptotic pathways may be initiated inside various subcellular organelles. Increasing evidence indicates that hydrogen peroxide (H2O2) is closely related to cell apoptosis, particularly in the mitochondria. However, during the apoptotic process, the synergetic variation of H2O2 levels in different compartments is seldom explored, particularly in two important organelles: mitochondria and endoplasmic reticulum (ER). To solve this problem, we developed two new organelle-specific fluorescent probes termed MI-H2O2 and ER-H2O2 that can detect H2O2 in mitochondria and ER, respectively or simultaneously. Experimental results demonstrated that MI-H2O2 and ER-H2O2 display distinguishable excitation and emission spectra, as well as excellent organelle targeting capabilities. Therefore, we used MI-H2O2 and ER-H2O2 to successfully image exogenous or endogenous hydrogen peroxide in the mitochondria and ER. Interestingly, during diverse apoptotic stimuli, dual-color fluorescence imaging results revealed that the changes of H2O2 levels in mitochondria and ER are different. The H2O2 levels are enhanced in both the mitochondria and ER during the L-buthionine sulfoximine (BSO)-treated cell apoptosis process. During mitochondria-oriented apoptosis induced by carbonyl cyanide m-chlorophenylhydrazone (CCCP) or rotenone, H2O2 levels prominently and continuously increase in the mitochondria, whereas the ER H2O2 levels were found to rise subsequently after a delay. Moreover, during ER-oriented apoptosis induced by tunicamycin, ER is the major site for overproduction of H2O2, and delayed elevation of the H2O2 levels was found in the mitochondria. Altogether, this dual-probe and multicolor imaging approach may offer a proven methodology for studying molecular communication events on H2O2-related apoptosis and also other physiological and pathological processes within different subcellular organelles.
Co-reporter:Kehua Xu, Feng Wang, Xiaohong Pan, Renpu Liu, Jing Ma, Fanpeng Kong and Bo Tang
Chemical Communications 2013 - vol. 49(Issue 25) pp:NaN2556-2556
Publication Date(Web):2013/02/11
DOI:10.1039/C3CC38980D
A highly selective and sensitive near-infrared (NIR) fluorescence probe (Cy-NO2) for imaging nitroreductase was developed and was successfully applied to investigating the relationship between epithelial–mesenchymal transitions (EMTs) in tumour progression and intracellular hypoxic level.
Co-reporter:Guan-wei Cui, Wei-liang Wang, Ming-yue Ma, Ming Zhang, Xin-yuan Xia, Feng-yun Han, Xi-feng Shi, Ying-qiang Zhao, Yu-Bin Dong and Bo Tang
Chemical Communications 2013 - vol. 49(Issue 57) pp:NaN6417-6417
Publication Date(Web):2013/06/03
DOI:10.1039/C3CC42500B
The rational design of carbonaceous hybrid nanostructures is very important for obtaining high photoactivity. TiO2 particles strewn with an optimal quantity of carbon nanodots have a much higher photoactivity than that of TiO2 covered with a carbon layer, showing the importance of carbon morphology in the photocatalysis of carbonaceous hybrid nanostructures.
Co-reporter:Ping Li, Xia Duan, Zhenzhen Chen, Ying Liu, Ting Xie, Libo Fang, Xiaorui Li, Miao Yin and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 27) pp:NaN7757-7757
Publication Date(Web):2011/05/27
DOI:10.1039/C1CC11885D
The first near-infrared fluorescent probe was developed toward Cu2+. Based on the photo-induced electron transfer (PET) mechanism, the probe exhibited weak fluorescence. Upon the addition of Cu2+, it fluoresced strongly. The probe offered this unique capability, and was successfully applied to living cells, tissues and in vivo to visualize Cu2+.
Co-reporter:Kehua Xu, Shuxia Sun, Jing Li, Lu Li, Mingming Qiang and Bo Tang
Chemical Communications 2012 - vol. 48(Issue 5) pp:NaN686-686
Publication Date(Web):2011/12/01
DOI:10.1039/C1CC15844A
A near-infrared fluorescent probe (Trp-Cy) for endogenous ozone is presented, which exhibited a large stokes shift about 140 nm and a rapid fluorescence response to ozone with high selectivity and sensitivity.
Co-reporter:Feng Li, Yan Feng, Can Zhao, Peng Li and Bo Tang
Chemical Communications 2012 - vol. 48(Issue 1) pp:NaN129-129
Publication Date(Web):2011/11/03
DOI:10.1039/C1CC15694B
A sensitive and selective fluorescent sensing platform for bleomycin (BLM) was developed based on BLM-induced DNA strand scission and the difference in affinity of graphene oxide for single-stranded DNA containing different numbers of bases in length.
Co-reporter:Na Li, Hui Wang, Mei Xue, Chenyang Chang, Zhenzhen Chen, Linhai Zhuo and Bo Tang
Chemical Communications 2012 - vol. 48(Issue 19) pp:NaN2509-2509
Publication Date(Web):2012/01/05
DOI:10.1039/C2CC16376D
A novel fluorescent nanoprobe with high sensitivity and selectivity for detection and imaging of the superoxide anion radical () in living cells was designed and synthesized by a simple self-assembly method based on 2-chloro-1,3-dibenzothiazoline-cyclohexene (DBZTC) and Ag@SiO2 core–shell nanoparticles.
Co-reporter:Mei Xue, Xu Wang, Hui Wang, Dezhan Chen and Bo Tang
Chemical Communications 2011 - vol. 47(Issue 17) pp:NaN4988-4988
Publication Date(Web):2011/03/22
DOI:10.1039/C0CC05389A
Specific hydrogen bond breakage by fluoride anions was observed in a simple FRET system formed by thioglycolic acid modified CdTe quantum dots and citrate-capped gold nanoparticles.
Co-reporter:Jie Ding, Xu Wang, Lin-Hai Zhuo and Bo Tang
Journal of Materials Chemistry A 2009 - vol. 19(Issue 19) pp:NaN3032-3032
Publication Date(Web):2009/03/17
DOI:10.1039/B819230H
High aspect ratio CdTe nanostructures were fabricated by hierarchical assembly of nanoparticles at the water–oil interface. The nature of two distinct morphologies, nanotubes and nanowires, was explored as a function of preparation parameters. Semiconductor CdTe nanoparticles covered with a mixed monolayer of n-dodecanethiol and thioglycollic acid were prepared and found to mediate the oil–water interface by assembly. CdTe nanoparticles in water phase, as starting materials, initiated the synthesis of nanotubes and nanowires. Acetone as an additional component was crucial in the phase transfer process. Some factors, including reaction temperature, reaction time, additional components, and reactant ratio, controlled the morphology of the products. The present method could be readily used to construct nanostructures possessing biological application potentials.
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4-amino-2',7'-difluoro-3',6'-dihydroxy-5-(methylamino)-](/data/chemimg/21300/254109-20-1.png)
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4-amino-2',7'-difluoro-3',6'-dihydroxy-5-(methylamino)-](/data/chemimg/21300/254109-20-1_b.png)
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![Dinaphtho[2,1-q:1',2'-s][1,4,7,10,13,16]hexaoxacycloeicosin,4,5,7,8,10,11,13,14,16,17-decahydro-, (24bR)-](http://img.cochemist.com/ccimg/75700/75684-69-4.png)
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