Co-reporter:Min You, Shuai Yang, Wanxin Tang, Fan Zhang, and Pin-Gang He
ACS Applied Materials & Interfaces April 26, 2017 Volume 9(Issue 16) pp:13855-13855
Publication Date(Web):April 10, 2017
DOI:10.1021/acsami.7b00444
Herein we propose a multiple signal amplification strategy designed for ultrasensitive electrochemical detection of glycoproteins. This approach introduces a new type of boronate-affinity sandwich assay (BASA), which was fabricated by using gold nanoparticles combined with reduced graphene oxide (AuNPs-GO) to modify sensing surface for accelerating electron transfer, the composite of molecularly imprinted polymer (MIP) including 4-vinylphenylboronic acid (VPBA) for specific capturing glycoproteins, and SiO2 nanoparticles carried gold nanoparticles (SiO2@Au) labeled with 6-ferrocenylhexanethiol (FcHT) and 4-mercaptophenylboronic acid (MPBA) (SiO2@Au/FcHT/MPBA) as tracing tag for binding glycoprotein and generating electrochemical signal. As a sandwich-type sensing, the SiO2@Au/FcHT/MPBA was captured by glycoprotein on the surface of imprinting film for further electrochemical detection in 0.1 M PBS (pH 7.4). Using horseradish peroxidase (HRP) as a model glycoprotein, the proposed approach exhibited a wide linear range from 1 pg/mL to 100 ng/mL, with a low detection limit of 0.57 pg/mL. To the best of our knowledge, this is first report of a multiple signal amplification approach based on boronate-affinity molecularly imprinted polymer and SiO2@Au/FcHT/MPBA, exhibiting greatly enhanced sensitivity for glycoprotein detection. Furthermore, the newly constructed BASA based glycoprotein sensor demonstrated HRP detection in real sample, such as human serum, suggesting its promising prospects in clinical diagnostics.Keywords: boronate-affinity sandwich assay; electrochemical sensor; glycoproteins; multiple signal amplification; oriented surface imprinting;
Co-reporter:Baoping Chen, Qingqing Hu, Qiang Xiong, Fan Zhang, Pingang He
Electrochimica Acta 2016 Volume 192() pp:127-132
Publication Date(Web):20 February 2016
DOI:10.1016/j.electacta.2015.12.102
The long DNA concatemers have been well developed to fabricate various biosensing platforms for the signal amplification. Herein, this signal amplification strategy was firstly used for an ultrasensitive scanning electrochemical microscopy (SECM)-based DNA biosensing platform. This platform was constructed through the hybridization of target DNA (TD) with thiol-tethered DNA capture probes (CP), immobilized on the gold substrate surface, and biotinylated DNA signal probes (SP), which formed then the long DNA concatemers through the continuous self-assembly with alternating DNA auxiliary probes (AP). The streptavidin-horseradish peroxidase (HRP) was linked to the long DNA concatemers through biotin-streptavidin interaction. In the HRP-catalyzed reaction, hydroquinone (H2Q) was oxidized to benzoquinone (BQ) with H2O2 at the modified substrate surface where sequence-specific hybridization had occurred, and the BQ generated could be monitored by a SECM tip. This platform exhibited a low detection limit of 0.18 aM estimated by the 3σ rule. Combined with DNA microarrays, four kinds of TDs (100 fM) as the models were detected simultaneously by using this proposed strategy, which also demonstrated sufficient selectivity to distinguish specific DNA sequences and good reproducibility. This method opens a promising direction to improve the SECM sensitivity for high-throughput DNA detection.
Co-reporter:Min You, Shuai Yang, Fang Jiao, Li-zhu Yang, Fan Zhang, Pin-Gang He
Electrochimica Acta 2016 Volume 199() pp:133-141
Publication Date(Web):1 May 2016
DOI:10.1016/j.electacta.2016.03.151
•A novel label-free electrochemical multi-sites recognition strategy of G-rich DNA was designed and MWCNTs-MIP with guanine recognition sites of DNA was employed as the recognition material.•Under the optimized experimental conditions, MWCNTs-MIP presented high selectivity for G-rich DNA and the imprinting factor of this composite was nearly 5.68.•A wider linear range (0.05–1 μM and 5–30 μM, respectively) and a higher sensitivity (detection limit: 7.52 nM, S/N = 3) was realized in the detection of G-rich DNA by the MWCNTs-MIP.A novel label-free electrochemical strategy was designed for multi-sites recognizing the guanine-rich DNA (G-rich DNA) with surface molecular imprinting polymer composite, in which the multi-walled carbon nanotubes (MWNCTs) were regarded as supporting material and the molecularly imprinted polymer (MIP) with guanine sites of DNA was applied as recognition element. Firstly, the vinyl groups were grafted onto the surface of carboxylic acid-functionalized MWNCTs (MWCNTs-COOH) through chemical modification. Then, the composite of MWCNTs-MIP was fabricated by the selective copolymerization of methacrylic acid, ethylene glycol dimethacrylate and guanine on the vinyl group-functionalized MWNTs surface. MWCNTs-MIP was characterized by different techniques, including Fourier transform infrared (FTIR) spectroscopy, scanning electronic microscopy (SEM), cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS), showing that the MWCNTs-MIP composite was successfully prepared. Under the optimized conditions, the imprinting factor was nearly 5.68 according to the comparative slopes obtained on MWCNT-MIP and MWCNTs-non-imprinted polymer (MWCNTs-NIP), indicating that MWCNTs-MIP exhibited high selectivity for G-rich DNA. Moreover, the MWCNTs-MIP composite had a relatively wide linear range over G-rich DNA concentration of 0.05–1 μM and 5–30 μM with a detection limit of 7.52 nM (S/N = 3). Furthermore, the novel electrochemical strategy based on imprinted composite has very excellent performance in real samples of human serum and human urine.
Co-reporter:Shuai Yang, Lijing Liu, Min You, Fan Zhang, Xiaojuan Liao, Pingang He
Sensors and Actuators B: Chemical 2016 Volume 227() pp:497-503
Publication Date(Web):May 2016
DOI:10.1016/j.snb.2015.12.090
•The sensing platform for DNA was constructed based on host–guest interaction between novel pillararenes and alkylamino modified DNA.•The sensing platform could be recycled after simple washing with hot acetonitrile.•The sensing platform exhibited wide linear range and excellent specificity.•Homogeneous DNA hybridization was utilized taking the advantage of free of previous immobilization of DNA probe.In this work, a recyclable electrochemical sensing platform to detect breast cancer susceptibility gene (BRCA) was constructed by pillararenes based host–guest recognition and homogeneous DNA hybridization. BRCA target DNA (T-DNA) formed sandwich-type DNA via homogeneous hybridization with methylene blue labeled signal DNA and alkylamino modified capture DNA, which could form complexes with pillararenes. Such sandwich-type DNA was captured by a novel trithiocarbonate modified pillar[5]arene (P5A-CTA) which was immobilized on the Au electrode. With the help of enzyme amplification, the electrochemical detection signal of target DNA in sensing platform was apparently amplified. This sensing platform exhibited wide linear range and excellent specificity, and was particularly recyclable after simple washing with hot acetonitrile due to the reversible host–guest complexation between P5A-CTA and alkylamino modified DNA.
Co-reporter:Fan Zhang, Ying-Ying Zhao, Hong Chen, Xiu-Hua Wang, Qiong Chen and Pin-Gang He
Chemical Communications 2015 vol. 51(Issue 30) pp:6613-6616
Publication Date(Web):18 Feb 2015
DOI:10.1039/C5CC00428D
A new series of photoactive metallocyclodextrins with increased fluorescence intensity upon binding with ssDNAs/aptamers has been demonstrated to sensitively and selectively detect lysozyme. The detection mechanism relies on the formation of an aptamer–lysozyme complex, which leads to reduction of fluorescence intensity.
Co-reporter:Na Zhang, Wei Ma, Pin-Gang He, Yi-Tao Long
Journal of Electroanalytical Chemistry 2015 Volume 739() pp:197-201
Publication Date(Web):15 February 2015
DOI:10.1016/j.jelechem.2014.12.007
•A new kind of thiol dopamine derivatives was synthesized.•Polydopamine monolayer as a platform for secondary reaction.•Horseradish peroxidase was adhered on the polydopamine monolayer.•The HRP on the monolayer catalyzed the oxidation of H2O2 obviously.Here, polydopamine derivative monolayer was generated by electro-polymerization of thiol dopamine derivatives modified on gold electrode, and the adhesion of polydopamine made it being a platform for secondary reaction. The influence of pH on formation of polydopamine derivative was investigated. Horseradish peroxidase (HRP) was adhered on the polydopamine derivative monolayer electrode catalyzing the oxidation of H2O2. Cyclic voltammetry (CV) was used to detect the polydopamine monolayer as well as electrochemical catalysis of H2O2. Besides, electrochemical impedance spectroscopy (EIS) and atomic force microscope (AFM) were also employed to characterize the polymeric monolayer.
Co-reporter:Zhen Gu, Yi-Lun Ying, Bing-Yong Yan, Hui-Feng Wang, Pin-Gang He, Yi-Tao Long
Chinese Chemical Letters 2014 Volume 25(Issue 7) pp:1029-1032
Publication Date(Web):July 2014
DOI:10.1016/j.cclet.2014.05.009
Nanopore technique plays an important role in single molecule detection, which illuminates the properties of an individual molecule by analyzing the blockage durations and currents. However, the traditional exponential function is lack of efficiency to describe the distributions of blockage durations in nanopore experiments. Herein, we introduced an exponentially modified Gaussian (EMG) function to fit the duration histograms of both simulated events and experimental events. In comparison with the traditional exponential function, our results demonstrated that the EMG provides a better fit while covers the entire range of the distributions. In particular, the fitted parameters of EMG could be directly used to discriminate the sequence length of the oligonucleotides at single molecule level.We introduced the EMG function to fit the distributions of blockage durations in nanopore-based experiments, which is well performed for revealing the behaviors of biomolecules at single molecule level.
Co-reporter:Qiong Chen, Hong Chen, Yingying Zhao, Fan Zhang, Fan Yang, Jie Tang, Pingang He
Biosensors and Bioelectronics 2014 Volume 54() pp:547-552
Publication Date(Web):15 April 2014
DOI:10.1016/j.bios.2013.11.028
•Tris(bpyRu)-β-CD is first synthesized in our group and possesses of great ECL performance as well as good recognition capability.•The host–guest recognition between tris(bpyRu)-β-CD and aptamer is employed to construct a label-free ECL-based aptasensor.•A detection limit of 0.1 pM without any other signal labeling or amplifying procedures is obtained in our approach.•The proposed aptasensor exhibits excellent sensitivity, operability and simplicity so that it offers great potential for detection of other targets.An ultrasensitive label-free electrochemiluminescence (ECL) aptasensor for the detection of thrombin was developed based on the specific recognition between tris(bipyridine)ruthenium(II)-β-cyclodextrin (tris(bpyRu)-β-CD) and the anti-thrombin aptamer (aptamer). The NH2-aptamer was first immobilized on the activated glassy carbon electrode (GCE) by coupling interaction. By use of the specific recognition between tris(bpyRu)-β-CD and aptamer, tris(bpyRu)-β-CD was then attached on the surface of GCE. Resulting from the outstanding photoactive properties of tris(bpyRu)-β-CD, the fabricated GCE performed strong ECL signal with the coreactant of 2-(dibutylamino)ethanol (DBAE). However, in the presence of thrombin, aptamer–thrombin bioaffinity complexes were formed, which restricted the recognition activities between aptamer and tris(bpyRu)-β-CD. Thus, fewer tris(bpyRu)-β-CD could be attached on the surface of GCE and led to an obvious decrease of ECL signal. Fortunately, the difference of ECL intensity before and after combination with thrombin was logarithmically linear with the concentration of thrombin in a wide range of 10 nM–1pM. Meantime, a detection limit of 0.1 pM without any other signal labeling or amplifying procedures indicated that the biosensor performed excellent sensitivity, operability and simplicity.
Co-reporter:Na Zhang;Yong-Xu Hu;Zhen Gu;Yi-Lun Ying
Science Bulletin 2014 Volume 59( Issue 35) pp:4942-4945
Publication Date(Web):2014 December
DOI:10.1007/s11434-014-0660-4
We presented an integrated software system for analyzing nanopore data. This self-developed software provided rapid processes for accurate location, classification, and evaluation of every individual blockade. Using the proposed software, statistical analysis could be achieved easily and conveniently. The results of β-Amyloid 42 demonstrated that our data process could rapidly extract duration time and current amplitudes. In addition, our data process could accurately carry out statistical fittings.提出了一套纳米通道数据分析集成软件系统。利用该自主开发的软件,能够对复杂庞大的纳米通道实验数据进行快速读取、处理、分类、统计并形成图表。该系统数据处理速度快、准确度高,可处理不同环境与检测条件下得到的各种纳米通道数据,通过灵活设定处理系统的各项参数以满足各种数据分析目的。本文以β-淀粉样蛋白(β-Amyloid 42)为例证明这一数据分析系统可以快速读取单个纳米通道信号的阻断时间与阻断电流,并且能够对统计数据进行精准拟合。
Co-reporter:Hong Chen, Qiong Chen, Yingying Zhao, Fan Zhang, Fan Yang, Jie Tang, Pingang He
Talanta 2014 Volume 121() pp:229-233
Publication Date(Web):April 2014
DOI:10.1016/j.talanta.2013.12.039
•A tris(bpyRu)-β-CD complex was newly synthesized by our group.•The tris(bpyRu)-β-CD had both photoactive properties and recognition capabilities.•Host–guest recognition was used to construct a sensitive ECL aptasensor.•A detection limit of 0.01 nM ATP was obtained, without any other signal labeling.•The aptasensor had excellent sensitivity, high efficiency, and good selectivity.A sensitive and label-free electrochemiluminescence (ECL) aptasensor for the detection of adenosine triphosphate (ATP) was successfully designed using host–guest recognition between a metallocyclodextrin complex, i.e., tris(bipyridine)ruthenium(II)-β-cyclodextrin [tris(bpyRu)-β-CD], and an ATP-binding aptamer. In the protocol, the NH2-terminated aptamer was immobilized on a glassy carbon electrode (GCE) by a coupling interaction. After host–guest recognition between tris(bpyRu)-β-CD and aptamer, the tris(bpyRu)-β-CD/aptamer/GCE produced a strong ECL signal as a result of the photoactive properties of tris(bpyRu)-β-CD. However, in the presence of ATP, the ATP/aptamer complex was formed preferentially, which restricted host–guest recognition, and therefore less tris(bpyRu)-β-CD was attached to the GCE surface, resulting in an obvious decrease in the ECL intensity. Under optimal determination conditions, an excellent logarithmic linear relationship between the ECL decrease and ATP concentration was obtained in the range 10.0–0.05 nM, with a detection limit of 0.01 nM at the S/N ratio of 3. The proposed ECL-based ATP aptasensor exhibited high sensitivity and selectivity, without time-consuming signal-labeling procedures, and is considered to be a promising model for detection of aptamer-specific targets.
Co-reporter:Huajun Fan, Xiaolan Wang, Fang Jiao, Fan Zhang, Qingjiang Wang, Pingang He, and Yuzhi Fang
Analytical Chemistry 2013 Volume 85(Issue 13) pp:6511
Publication Date(Web):June 9, 2013
DOI:10.1021/ac4011155
Imaging of localized hybridization of nucleic acids immobilized on a glass DNA microarray was performed by means of generation collection (GC) mode scanning electrochemical microscopy (SECM). Amine-tethered oligodeoxynucleotide probes, spotted on the glass surface, were hybridized with an unmodified target sequence and a biotinylated indicator probe via sandwich hybridization. Spots where sequence-specific hybridization had occurred were modified by streptavidin-horseradish-peroxidase-(HRP)-wrapped SiO2 nanoparticles through the biotin–streptavidin interaction. In the presence of H2O2, hydroquinone (H2Q) was oxidized to benzoquinone (BQ) at the modified spot surface through the HRP catalytic reaction, and the generated BQ corresponding to the amount of target DNA was reduced in solution by an SECM tip. With this DNA microarray, a number of genes could be detected simultaneously and selectively enough to discriminate between complementary sequences and those containing base mismatches. The DNA targets at prepared spots could be imaged in SECM GC mode over a wide concentration range (10–7–10–12 M). This technique may find applications in genomic sequencing.
Co-reporter:Fang Jiao;Huajun Fan;Guangda Yang;Fan Zhang ;Pingang He
Journal of Molecular Recognition 2013 Volume 26( Issue 12) pp:672-678
Publication Date(Web):
DOI:10.1002/jmr.2312
Aptamers are single-stranded nucleic acid molecules that can be used for protein recognition, detection, and inhibition. Over the past decades, two thrombin-binding aptamers (15apt and 27apt) were reported by systemic evolution of ligands by exponential enrichment technique. Though many studies have been reported about the interactions between the aptamers and thrombin by atomic force microscopy, the thrombins in those studies were all immobilized by chemical agents. Recently, we developed a new method using atomic force microscopy to directly investigate the specific interactions between thrombin and its two aptamers without immobilizing the thrombin. Furthermore, the unbinding dynamics and dissociation energy landscapes of aptamer/thrombin were discussed. The results indicate that the underlying interaction mechanisms of thrombin with its two aptamers will be similar despite that the structures of 15apt and 27apt are different in buffer solution. Copyright © 2013 John Wiley & Sons, Ltd.
Co-reporter:Chen CHEN, Zhu CHANG, Li-Zhu YANG, Fan ZHANG, Pin-Gang HE, Yu-Zhi FANG
Chinese Journal of Analytical Chemistry 2013 Volume 41(Issue 7) pp:973-978
Publication Date(Web):July 2013
DOI:10.1016/S1872-2040(13)60738-0
Electrochemical DNA biosensor with high sensitivity of homogenous hybridization was fabricated on the basis of host-guest recognition between β-cyclodextrin (β-CD) and m-toluic acid (mTA). β-CD, as the host molecule, was electropolymerized on the poly(N-acetylaniline)-modified glassy carbon electrode, and mTA, was labeled on the probe DNA as the guest through acid-amine condensation reaction. Two intercalators were used as electrochemical indicators to detect DNA hybridization:methylene blue (MB) and daunorubicin (DNM). The electrochemical signals of MB were linear in the range of complementary DNA from 2.0 × 10−12 M to 2.0 × 10−10 M with a detection limit of 7.6 × 10−13 M. The electrochemical response of DNM was linear with the concentrations of complementary from 1 × 10−12 M to 1 × 10−9 M with a detection limit of 6.0 × 10−13 M. This DNA biosensing technique exhibited excellent reproducibility and stability.
Co-reporter:Fan ZHANG, Hong CHEN, Pin-Gang HE, Yu-Zhi FANG
Chinese Journal of Analytical Chemistry 2013 Volume 41(Issue 1) pp:1-9
Publication Date(Web):January 2013
DOI:10.1016/S1872-2040(13)60618-0
Electrochemiluminescence (ECL) signal is generated directly or indirectly by the electrochemical reactions. Due to its characteristics of high sensitivity, specificity, easy realization of integration, real-time and in-situ detection, ECL detection provides powerful research tools and methods in life sciences at molecular level. Research on deoxyribonucleic acid (DNA) is an extremely important aspect in life science and shows the significance in the areas of forensic identification, epidemic prevention and environmental monitoring, especially for the early diagnosis and treatment of diseases. DNA-ECL biosensing is considered as the most promising technology for DNA analysis and has been a hot research topic in the fields of biology and medicine. This review summarizes the research on DNA-ECL biosensing technologies in China in the recent five years. Also, we look into its research prospects.
Co-reporter:Dr. Hong Chen;Dr. Xiuhua Wang;Dr. Yantao Qi;Shanshan Zheng;Qiong Chen; Pingang He;Dr. Fan Zhang; Fan Yang; Jie Tang; Yuzhi Fang
ChemPlusChem 2013 Volume 78( Issue 8) pp:780-784
Publication Date(Web):
DOI:10.1002/cplu.201300071
Co-reporter:Huajun Fan, Fang Jiao, Hong Chen, Fan Zhang, Qingjiang Wang, Pingang He, Yuzhi Fang
Biosensors and Bioelectronics 2013 Volume 47() pp:373-378
Publication Date(Web):15 September 2013
DOI:10.1016/j.bios.2013.03.027
•Qualitative and quantitative detection of DNA use SG/TC mode of SECM.•The detection signals were amplified by HRP-wrapped SiO2 nanoparticles.•The detection limit for complementary DNA was as low as 0.8 pM.Qualitative and quantitative detection of DNA was achieved by a “sandwich” DNA sensor through SG/TC (substrate generation and tip collection) mode of scanning electrochemical microscopy (SECM). The “sandwich” DNA structure was formed by the hybridization of thiol-tethered oligodeoxynucleotide probes (capture probe), assembled on the gold substrate surface, with target DNA and biotinylated indicator probe. HRP (horseradish peroxidase)-wrapped SiO2 nanoparticles were linked to the sandwich structure through biotin–streptavidin interaction. Hydroquinone (H2Q) was oxidized to benzoquinone (BQ) at the modified substrate surface where sequence-specific hybridization had occurred through the HRP-catalyzed reaction in the presence of H2O2. The detection was based on the reduction of BQ generated on the modified substrate by SECM tip. For SECM imaging experiment, we structured the microsensor platform through localized desorption of 1-dodecanethiol monolayer. Approach curves were employed for quantitative detection of DNA concentration. The detection limit of complementary DNA was as low as 0.8 pM. This technique is promising for the application on electrochemical DNA chip.
Co-reporter:Yu Cheng, Guoxiang Xie, Tianlu Chen, Yunping Qiu, Xia Zou, Minhua Zheng, Binbin Tan, Bo Feng, Taotao Dong, Pingang He, Linjing Zhao, Aihua Zhao, Lisa X. Xu, Yan Zhang, and Wei Jia
Journal of Proteome Research 2012 Volume 11(Issue 2) pp:1354-1363
Publication Date(Web):2017-2-22
DOI:10.1021/pr201001a
A full spectrum of metabolic aberrations that are directly linked to colorectal cancer (CRC) at early curable stages is critical for developing and deploying molecular diagnostic and therapeutic approaches that will significantly improve patient survival. We have recently reported a urinary metabonomic profiling study on CRC subjects (n = 60) and health controls (n = 63), in which a panel of urinary metabolite markers was identified. Here, we report a second urinary metabonomic study on a larger cohort of CRC (n = 101) and healthy subjects (n = 103), using gas chromatography time-of-flight mass spectrometry and ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry. Consistent with our previous findings, we observed a number of dysregulated metabolic pathways, such as glycolysis, TCA cycle, urea cycle, pyrimidine metabolism, tryptophan metabolism, polyamine metabolism, as well as gut microbial–host co-metabolism in CRC subjects. Our findings confirm distinct urinary metabolic footprints of CRC patients characterized by altered levels of metabolites derived from gut microbial–host co-metabolism. A panel of metabolite markers composed of citrate, hippurate, p-cresol, 2-aminobutyrate, myristate, putrescine, and kynurenate was selected, which was able to discriminate CRC subjects from their healthy counterparts. A receiver operating characteristic curve (ROC) analysis of these markers resulted in an area under the receiver operating characteristic curve (AUC) of 0.993 and 0.998 for the training set and the testing set, respectively. These potential metabolite markers provide a novel and promising molecular diagnostic approach for the early detection of CRC.
Co-reporter:Hao Fan, Hui Li, Qingjiang Wang, Pingang He, Yuzhi Fang
Biosensors and Bioelectronics 2012 Volume 35(Issue 1) pp:33-36
Publication Date(Web):15 May 2012
DOI:10.1016/j.bios.2012.01.027
A sensitive electrochemical aptasensor for thrombin detection is presented based on the host-guest recognition technique. In this sensing protocol, a 15 based thrombin aptamer (ab. TBA) was dually labeled with a thiol at its 3′ end and a 4-((4-(dimethylamino)phenyl)azo) benzoic acid (dabcyl) at its 5′ end, respectively, which was previously immobilized on one Au electrode surface by AuS bond and used as the thrombin probe during the protein sensing procedure. One special electrochemical marker was prepared by modifying CdS nanoparticle with β-cyclodextrins (ab. CdS-CDs), which employed as electrochemical signal provider and would conjunct with the thrombin probe modified electrode through the host–guest recognition of CDs to dabcyl. In the absence of thrombin, the probe adopted linear structure to conjunct with CdS-CDs. In present of thrombin, the TBA bond with thrombin and transformed into its special G-quarter structure, which forced CdS-CDs into the solution. Therefore, the target-TBA binding event can be sensitively transduced via detecting the electrochemical oxidation current signal of Cd of CdS nanoparticles in the solution. Using this method, as low as 4.6 pM thrombin had been detected.Highlights► We constructed an electrochemical aptasensor for thrombin detection based on the host-guest recognition technique. ► Conformation-change-based electronic biosensors. ► The mono(6-O-4-aminophenoxy) heptakis(2,3-O-diacetyl) β-cyclodextrin (MPA-β-CD) was synthesized.
Co-reporter:Lizhu Yang, Ying Xu, Xiuhua Wang, Jing Zhu, Renyi Zhang, Pingang He, Yuzhi Fang
Analytica Chimica Acta 2011 Volume 689(Issue 1) pp:39-46
Publication Date(Web):9 March 2011
DOI:10.1016/j.aca.2011.01.026
We functionalized aligned carbon nanotubes (ACNTs) electrode with a new kind of β-cyclodextrin (β-CD) derivative through diazotization reaction. The resulting β-CD/ACNTs electrode was used to detect DNA hybridization in homogeneous solution based on host–guest recognition technology. In the sensing protocol, one special DNA probe was designed with a stem-loop structure and both ends modified, which we called dually labeled DNA probe (DLP). One end of the DLP was labeled with dabcyl as guest molecule for β-CD/ACNTs electrode capture, and the other end was labeled with a CdS nanoparticle as an electrochemical tag to indicate the occurrence of DNA hybridization. In the absence of the target DNA sequence, the DLP maintains its hairpin structure in solution phase and would not be captured and detected by the β-CD/ACNTs electrode. In the presence of the complementary target sequence, the conformational structure of the DLP was altered and a double-stranded DNA (dsDNA) molecule was formed by the hybridization of DLP and complementary DNA sequence. Consequently, the dsDNA was captured by the β-CD/ACNTs electrode owing to guest–host recognition between β-CD and dabcyl. The electrochemical signal from the CdS nanoparticle–dsDNA/β-CD/ACNTs was then measured. Under optimized detection conditions, the proposed method showed high sensitivity and selectivity with a detection limit of 5.0 × 10−13 M for complementary DNA sequence.
Co-reporter:Xiaoying Wang, Xiangyi Zhang, Pingang He, Yuzhi Fang
Biosensors and Bioelectronics 2011 Volume 26(Issue 8) pp:3608-3613
Publication Date(Web):15 April 2011
DOI:10.1016/j.bios.2011.02.012
An enzyme-based solid-state electrochemiluminescence (ECL) sensing platform for sensitive detection of a single point mutation is developed successfully using p53 tumor suppressor gene as a model analyte. A composite of multiwalled carbon nanotubes and Ruthenium (II) tris-(bipyridine) (MWNTs–Ru(bpy)32+) was prepared and coated on an electrode surface, which was covered by polypyrrole (PPy) to immobilize ssDNA. Then, the ssDNA recognized the gold nanoparticle (AuNP)-labeled p53 tumor suppressor gene, and produced AuNP-dsDNA electrode with AuNP layer. The surface adsorbed the glucose-dehydrogenase (GDH) molecules for producing ECL signal. This system combined enzyme reaction with ECL detection, and it can recognize sequence-specific wild type p53 sequence (wtp53) and muted type p53 sequence (mtp53) with discrimination of up to 56.3%. The analytic results were sensitive and specific. It holds promise for the diagnosis and management of cancer.
Co-reporter:Ying Xu;Ping Dong;XiaoYan Zhang;PinGang He;YuZhi Fang
Science China Chemistry 2011 Volume 54( Issue 7) pp:1109-1115
Publication Date(Web):2011 July
DOI:10.1007/s11426-011-4278-y
One solid-state electrochemiluminescence (ECL) protein biosensor based on the competing reaction and substitute reaction between protein-to-DNA aptamer and DNA-to-DNA aptamer was proposed. Additionally, the biosensor was based on ECL photo-quenching effect of ferrocene (Fc) to tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+). It was built up by modification of Au nanoparticles (AuNPs) and Ru(bpy)32+ on one Au electrode firstly, and then self-assembly of one special double-stranded DNA (dsDNA) onto the electrode. This dsDNA was prepared by hybridization of one Fc labeled molecular beacon single-stranded DNA(ssDNA) and one anti-thrombin aptamer ssDNA. Without the target protein, this Fc-dsDNA/Ru(bpy)32+-AuNPs/Au electrode trigged strong ECL signal, so we called it ECL “signal on” state. When thrombin was present in the sensing solution, the protein reacted with its aptamer from the Fc-dsDNA/Ru(bpy)32+-AuNPs/Au electrode. Then the left molecular beacon ssDNA on the electrode recovered to its normal stem-loop structure and consequently its Fc labeler was close enough to the electrode surface to quench the ECL signal from Ru(bpy)32+. It was in ECL “signal off” state. We measured the decrease in ECL intensity to sense the target protein. This was one endeavour to sense protein by using un-labeling target or probe strategy, which gave higher sensitivity and selectivity due to the better combination efficiency of protein and the un-labeled aptamer. 6.25 fmol/L thrombin was detected out.
Co-reporter:Ying Xu;ShuQi Zhuang;XiaoYan Zhang;PinGang He;YuZhi Fang
Science Bulletin 2011 Volume 56( Issue 35) pp:3823-3828
Publication Date(Web):2011 December
DOI:10.1007/s11434-011-4745-z
Aligned carbon nanotubes (ACNTs) were modified with polypyrrole (PPy) via electropolymerization. Because of the large specific surface area and excellent electrical conductivity of ACNTs, continuous electropolymerization was able to be carried out, forming a thick PPy coating on the ACNTs. The resulting nanocomposite possessed a core-shell structure with ACNTs as the core, PPy as the shell, and nanoparticles of PPy on the top, and displayed high performance supercapacitance properties.
Co-reporter:Hao Fan, Rong Xing, Ying Xu, Qingjiang Wang, Pingang He, Yuzhi Fang
Electrochemistry Communications 2010 Volume 12(Issue 4) pp:501-504
Publication Date(Web):April 2010
DOI:10.1016/j.elecom.2009.11.030
This communication reports on a new electrochemical method to detect the hybridization specificity by using host–guest recognition technique. A hairpin DNA with dabcyl-labeled at its 3′ and NH2 group at 5′ terminal was combined with CdS nanoparticle to construct a double-labeled probe (DLP), which could selectively hybridize with its target DNA in homogeneous solution. A β-CD modified Poly(N-acetylaniline) glassy carbon electrode was used for capturing the dabcyl label in DLP. When without binding with target DNA, the DLP kept its stem-loop structure which shielded the dabcyl molecule due to the loop of the hairpin DNA and CdS nanoparticle blocking dabcyl enter into the cavity of these β-CD molecules on the electrode. However, in present of complementary sequence, the target-binding DLP was incorporated into double stranded DNA, causing the DLP’s loop-stem structure opened and then the dabcyl was easily captured by the β-CD modified electrode. During electrochemical measurement, the signal from the dissolved Cd2+ was used for target DNA quantitative analysis.
Co-reporter:Xiaoying Wang, Ping Dong, Pingang He, Yuzhi Fang
Analytica Chimica Acta 2010 Volume 658(Issue 2) pp:128-132
Publication Date(Web):25 January 2010
DOI:10.1016/j.aca.2009.11.007
A solid-state electrochemiluminescence sensing platform based on ferrocene-labeled structure-switching signaling aptamer (Fc-aptamer) for highly sensitive detection of small molecules is developed successfully using adenosine as a model analyte. Such special sensing platform included two main parts, an electrochemiluminescence (ECL) substrate and an ECL intensity switch. The ECL substrate was made by modifying the complex of Au nanoparticle and Ruthenium (II) tris-(bipyridine) (Ru(bpy)32+–AuNPs) onto Au electrode. An anti-adenosine aptamer labeled by ferrocene acted as the ECL intensity switch. A short complementary ssDNA for the aptamer was applied to hybridizing with the aptamer, yielding a double-stranded complex of the aptamer and the ssDNA on the electrode surface. The introduction of adenosine triggered structure switching of the aptamer. As a result, the ssDNA was forced to dissociate from the sensing platform. Such structural change of the aptamer resulted in an obvious ECL intensity decrease due to the increased quenching effect of Fc to the ECL substrate. The analytic results were sensitive and specific.
Co-reporter:Zhiyong Yang;Zicheng Li;Jinkun Zhu;Qingjiang Wang;Pingang He;Yuzhi Fang
Journal of Separation Science 2010 Volume 33( Issue 9) pp:1312-1318
Publication Date(Web):
DOI:10.1002/jssc.200900586
Abstract
With a view of simultaneous determination of physio-active ingredients in oolong tea infusion: sugars, amino acids, epigallocatechin gallate and ascorbic acid, a novel CZE with amperometric detection method was studied. Operated in a wall-jet configuration, 100 mmol/L NaOH was used in detecting cell to lead the electrocatalysis oxidation behaviors of the analytes on a 300 μm diameter copper-disc electrode (working electrode), while in separating capillary, a mild alkaline running buffer consisting in a mixture of 30 mmol/L borate and 40 mmol/L phosphates charged and carried analytes to detecting end. The methodology research was performed for system stability and suitability. Under the optimal CE conditions, analytes could be separated within moderate time period. Good linearity between peak area and concentration existed over three orders of magnitude; lower RSD and LOD were achieved. The oolong tea infusion was assayed and result was satisfactory.
Co-reporter:Xiaoying Wang, Pingang He, Yuzhi Fang
Journal of Luminescence 2010 Volume 130(Issue 8) pp:1481-1484
Publication Date(Web):August 2010
DOI:10.1016/j.jlumin.2010.03.016
A solid-state electrochemiluminescence (ECL) biosensing switch incorporating quenching of ECL of ruthenium(II) tris-(bipyridine) (Ru(bpy)32+) by ferrocene (Fc) has been successfully developed for DNA hybridization detection. The important issue for this biosensing system is based on the ferrocene-labeled molecular beacon (Fc-MB), i.e. using the special Fc-MB to react with the target DNA and then change its structure, resulting in an ECL intensity change. Under the optimal conditions, the difference of ECL intensity before and after the hybridization reaction (ΔIECL) was linearly related to the concentration of the complementary sequence in the range of 10 fM–10 pM and the detection limit was down to 1.0 fM.
Co-reporter:Hao Fan;Rong Xing;Ying Xu;Miao Chen; Dr. Qingjiang Wang; Dr. Pingang He;Yuzhi Fang
Chinese Journal of Chemistry 2010 Volume 28( Issue 10) pp:1978-1982
Publication Date(Web):
DOI:10.1002/cjoc.201090330
Abstract
A competitor-switched electrochemical sensor based on a generic displacement strategy was designed for DNA detection. In this strategy, an unmodified single-stranded DNA (cDNA) completely complementary to the target DNA served as the molecular recognition element, while a hairpin DNA (hDNA) labeled with a ferrocene (Fc) and a thiol group at its terminals served as both the competitor element and the probe. This electrochemical sensor was fabricated by self-assembling a dsDNA onto a gold electrode surface. The dsDNA was pre-formed through the hybridization of Fc-labeled hDNA and cDNA with their part complementary sequences. Initially, the labeled ferrocene in the dsDNA was far from surface of the electrode, the electrochemical sensor exhibited a "switch-off" mode due to unfavorable electron transfer of Fc label. However, in the presence of target DNA, cDNA was released from hDNA by target DNA, the hairpin-open hDNA restored its original hairpin structure and the ferrocene approached onto the electrode surface, thus the electrochemical sensor exhibited a "switch-on" mode accompanying with a change in the current response. The experimental results showed that as low as 4.4×10−10 mol/L target DNA could be distinguishingly detected, and this method had obvious advantages such as facile operation, low cost and reagentless procedure.
Co-reporter:Jing Zheng, Gui-Fang Cheng, Pin-Gang He, Yu-Zhi Fang
Talanta 2010 Volume 80(Issue 5) pp:1868-1872
Publication Date(Web):15 March 2010
DOI:10.1016/j.talanta.2009.10.036
An aptamer-based assay for thrombin with high specificity and sensitivity was presented. In the protocol, the aptamer for thrombin was immobilized on magnetic nanoparticle, and its complementary oligonucleotide was labeled with gold nanoparticles, then the aptamer was hybridized with the complementary oligonucleotide to form the duplex structure as a probe, this probe could be used for the specific recognition for thrombin. In the presence of thrombin, the aptamer prefer to form the G-quarter structure with thrombin, resulting in the dissociation of the duplex of the probe and the release of the gold labeled oligonucleotide. Upon this, we were able to detect thrombin through the detection of the electrochemical signal of gold nanoparticles. The strategy combines with the high specificity of aptamer and the excellent characteristics of nanoparticles. This assay is simple, rapid, sensitive and highly specific, it does not require labeling of thrombin, and it could be applied to detect thrombin in complex real sample. The method shows great potential in other protein analysis and in disease diagnosis.
Co-reporter:Zhiyong Yang;Linlin Zhang;Gang Li;Qingjiang Wang;Pingang He
Chromatographia 2010 Volume 71( Issue 5-6) pp:439-445
Publication Date(Web):2010 March
DOI:10.1365/s10337-009-1459-3
A composite electrode was fabricated from Cu2O powder, carboxyl-functionalized multi-wall carbon nanotubes (MWCNT-COOH), and paraffin oil in the proportions 51:17:32 (w/w). This composite electrode was used for amperometric detection (CZE–AD) in simultaneous capillary zone electrophoretic analysis of chlorogenic acid, rutin, sucrose, glucose, mannose, and fructose in tobacco samples. Under the optimum conditions, the six analytes could be separated in 100 mmol L−1 NaOH buffer within 30 min. Good linearity was achieved in the range 1 × 10−7–1 × 10−4 mol L−1 for the two polyphenols and 5 × 10−6–1 × 10−3 mol L−1 for the four sugars. The detection limits (S/N = 3) for the polyphenols and sugars were as low as 10−8 mol L−1 and 10−6 mol L−1, respectively.
Co-reporter:Xiaoying Wang, Ping Dong, Wen Yun, Ying Xu, Pingang He, Yuzhi Fang
Talanta 2010 Volume 80(Issue 5) pp:1643-1647
Publication Date(Web):15 March 2010
DOI:10.1016/j.talanta.2009.09.060
A solid-state electrochemiluminescence (ECL) biosensing switch based on special ferrocene-labeled molecular beacon (Fc-MB) has been successfully developed for T4 DNA ligase detection. Such special switch system consisted of two main parts, an ECL substrate and an ECL intensity switch. The ECL substrate was made by modifying the complex of Au nanoparticle and Ruthenium (II) tris-(bipyridine) (Ru(bpy)32+-AuNPs) onto Au electrode. A molecular beacon labeled by ferrocene as the ECL intensity switch. The molecular beacon is designed with special base sequence, which could combine with its target biomolecule via the reaction of the repair and recombination of nucleic acids by DNA ligase. During the reaction, the molecular beacon opened its stem–loop, and the labeled Fc was consequently kept away from the ECL substrate. Such structural change resulted in an obvious increment in ECL intensity due to the decreased Fc quenching effect to the ECL substrate. The analysis results are sensitive and specific.
Co-reporter:Guifang Cheng, Bijun Shen, Fan Zhang, Jikui Wu, Ying Xu, Pingang He, Yuzhi Fang
Biosensors and Bioelectronics 2010 Volume 25(Issue 10) pp:2265-2269
Publication Date(Web):15 June 2010
DOI:10.1016/j.bios.2010.03.008
A new electrochemical aptamer molecular beacon (MB) was designed by the carminic acid (CA) covalently linking at the each end of a special single-stranded stem-loop shaped oligonucleotide and named as CAs-MB. CA is an electrochemically active molecule and two CA molecules at the ends of molecular beacon stem were closed enough to associate each other to be as CA dimer. The dimer was electrochemically inactive. It separated into two CA monomers and produced the electrochemical signal while CAs-MB combined with target. In this protocol, the detection strategy of CAs-MB for thrombin is based on electrochemical active–inactive switching between monomer and dimer forms of CA. In order to enhance the electrochemical signal, magnetic nanobeads (MNB) was applied by connecting CAs-MB with MNB through a duplex of DNA. With the magnetic enrichment, the detection limit for thrombin reached to 42.4 pM. The experiment results showed that this type of electrochemical active–inactive switching aptamer molecular beacon allowed the direct detection of target proteins in the solution with no requirement of removing uncombined CAs-MB. Besides, CAs-MB/MNB can be easily regenerated by using 2 M NaCl solution to cleave the thrombin from the aptasensor.
Co-reporter:Guifang Cheng, Bijun Shen, Fan Zhang, Jikui Wu, Ying Xu, Pingang He, Yuzhi Fang
Biosensors and Bioelectronics 2010 Volume 26(Issue 1) pp:299
Publication Date(Web):15 September 2010
DOI:10.1016/j.bios.2010.05.029
Co-reporter:Jikui Wu, Cuihua Huang, Guifang Cheng, Fan Zhang, Pingang He, Yuzhi Fang
Electrochemistry Communications 2009 Volume 11(Issue 1) pp:177-180
Publication Date(Web):January 2009
DOI:10.1016/j.elecom.2008.10.053
We report a new kind of electrochemical molecular beacon, termed “electrochemically active–inactive switching molecular beacon”, for direct detection of DNA in homogenous solution. The electrochemical molecular beacon consists of a stable stem-loop oligonucleotide carrying two carminic acid moieties (acting as electrochemical reporter) attached at its termini. In a close form, the electrochemical signal is quenched because two carminic acid moieties are close enough to associate into dimer. In the presence of the complementary DNA target, the electrochemical molecular beacon undergoes a conformational transformation from closed (hairpin) to open (linear) structure, which is associated with an increase in electrochemical signal. We found that the electrochemical molecular beacon is as effective as conventional molecular beacon in signaling the presence of complementary target and discriminating targets that differ by a single nucleotide. The proposed electrochemical molecular beacon has a great potential for investigating the interactions of DNA-protein and developing electrochemical real-time polymerase chain reaction.
Co-reporter:Wen Yun, Ying Xu, Ping Dong, Xiongxiong Ma, Pingang He, Yuzhi Fang
Analytica Chimica Acta 2009 Volume 635(Issue 1) pp:58-62
Publication Date(Web):2 March 2009
DOI:10.1016/j.aca.2008.12.050
Tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) has been successfully immobilized onto electrode through the electrodeposition of Ru(bpy)32+/AuNPs/chitosan composite film. In the experiments, chitosan solution was first mixed with Au nanoparticles (AuNPs) and Ru(bpy)32+. Then, during chronopotentiometry experiments in this mixed solution, a porous 3D network structured film containing Ru(bpy)32+, AuNPs and chitosan has been electrodeposited onto cathode due to the deposition of chitosan when pH value is over its pKa (6.3). The applied current density is crucial to the film thickness and the amount of the entrapped Ru(bpy)32+. Additionally, these doping Ru(bpy)32+ in the composite film maintained their intrinsic electrochemical and electrochemiluminescence activities. Consequently, this Ru(bpy)32+/AuNPs/chitosan modified electrode has been used in ECL to detect tripropylamine, and the detection limit was 5 × 10−10 M.
Co-reporter:Fei Hui, Bin Li, Pingang He, Jun Hu, Yuzhi Fang
Electrochemistry Communications 2009 Volume 11(Issue 3) pp:639-642
Publication Date(Web):March 2009
DOI:10.1016/j.elecom.2008.12.051
A versatile method for preparing nanoporous polypyrrole (PPy) film using electrogenerated nanobubbles as templates on highly oriented pyrolytic graphite (HOPG) is presented using in situ electrochemical atomic force microscopy (EC-AFM).
Co-reporter:Xiaoying Wang, Ping Dong, Wen Yun, Ying Xu, Pingang He, Yuzhi Fang
Biosensors and Bioelectronics 2009 Volume 24(Issue 11) pp:3288-3292
Publication Date(Web):15 July 2009
DOI:10.1016/j.bios.2009.04.019
A solid-state electrochemiluminescence (ECL) biosensing switch system based on special ferrocene-labeled molecular beacon aptamer (Fc-MBA) has been developed successfully for thrombin detections. Such special switch system includes two main parts, an ECL substrate and an ECL intensity switch. The ECL substrate was made by modifying the complex of Au nanoparticle and Ruthenium (II) tris-(bipyridine) (Ru(bpy)32+–AuNPs) onto Au electrode. A molecular beacon aptamer labeled by ferrocene acted as the ECL intensity switch. The loop bases of the ECL intensity switch are designed with special anti-thrombin aptamer sequence which could be combined with its target protein via the reaction between aptamer and thrombin. During the reactions, the molecular beacon aptamer opened its stem-loop, and the labeled Fc was consequently kept away from the ECL substrate. Such structural change resulted in an obvious ECL intensity increment due to the decreased quenching effect of Fc to the ECL substrate. The analytic results are sensitive and specific.
Co-reporter:Wen Yun, Ping Dong, Ying Xu, Lizhu Yang, Pingang He, Yuzhi Fang
Sensors and Actuators B: Chemical 2009 Volume 141(Issue 1) pp:244-248
Publication Date(Web):18 August 2009
DOI:10.1016/j.snb.2009.04.063
Co-reporter:Zhu Chang, Miao Chen, Hao Fan, Kun Zhao, Shuqi Zhuang, Pingang He, Yuzhi Fang
Electrochimica Acta 2008 Volume 53(Issue 6) pp:2939-2945
Publication Date(Web):15 February 2008
DOI:10.1016/j.electacta.2007.11.004
A novel Au nanoparticles (Au-NPs)-based protocol for DNA hybridization detection based on assembly of alternating DNA and poly(dimethyldiallylammonium chloride) (PDDA) multilayer films by layer-by-layer (LBL) electrostatic adsorption has been studied. Electrochemical impedance spectroscopy (EIS) and UV–vis absorbance measurements were used to study the film assembly. All the results indicate that the uniform multilayer can be obtained on the polypyrrole (PPy) coated electrode surface and the hybridization reaction can be amplified by the layer-by-layer progress. The hybridization was detected by the reductive signal of Au-NPs and nonspecific adsorption was greatly eliminated by an unrelated DNA sequence to the target DNA. Under optimum conditions, a significant sensitivity enhancement had been obtained, and the detection limit was down to 3.20 × 10−14 M when 6 layers assembled. The DNA biosensor has good stability and reproducibility.
Co-reporter:Kun Zhao, Haiyan Song, Shuqi Zhuang, Liming Dai, Pingang He, Yuzhi Fang
Electrochemistry Communications 2007 Volume 9(Issue 1) pp:65-70
Publication Date(Web):January 2007
DOI:10.1016/j.elecom.2006.07.001
A thionine modified aligned carbon nanotubes (ACNTs) electrode was fabricated and was used to electrochemically determine nitrite. The thionine modified ACNTs electrode exhibited enhanced electrocatalytic behavior to the oxidation of nitrite. The electrochemical mechanism of the thionine/ACNTs electrode towards the oxidation of nitrite was discussed. The thionine modified ACNTs electrode exhibited fast response towards nitrite with a detection limit of 1.12 × 10−6 mol L−1 and a linear range of 3 × 10−6 – 5 × 10−4 mol L−1. The proposed method was successfully applied in the detection of nitrite in real samples.
Co-reporter:Xiaoying Wang, Jingming Zhou, Wen Yun, Shasha Xiao, Zhu Chang, Pingang He, Yuzhi Fang
Analytica Chimica Acta 2007 Volume 598(Issue 2) pp:242-248
Publication Date(Web):29 August 2007
DOI:10.1016/j.aca.2007.07.050
A sensitive and selective aptasensor using tri(2,2′-bipyridyl)ruthenium(II)-doped silica nanoparticles (Ru(bpy)32+-doped SNPs) as DNA tags for detection of thrombin is developed based on the target protein-induced strand displacement of the DNA probe. For the proposed aptasensor, the aptamer was assembled on the surface of the Au electrode through Au-S binding. The hybridization event between the DNA probe labeled by the Ru(bpy)32+-doped SNPs and the aptamer was evaluated by electrogenerated chemiluminescence (ECL) measurements. Then, the DNA probe was displaced by thrombin and the binding event between the thrombin and the aptamer was monitored by ECL measurements again. The difference of ECL intensity (ΔIECL) of the two events could be used to quantify the thrombin. Other proteins, such as bovine serum albumin and bovine hemoglobin, had almost negligible ΔIECL. Under the optimal conditions, the ΔIECL was linearly related to the concentration of the thrombin in the range of 10 fM to 10 pM and the detection limit was down to 1.0 fM since SNPs containing a large number of Ru(bpy)32+ molecules were labeled on the DNA probe.
Co-reporter:Juan Juan Ren, Hai Yan Liu, Yu Hong Hao, Pin Gang He, Yu Zhi Fang
Chinese Chemical Letters 2007 Volume 18(Issue 8) pp:985-988
Publication Date(Web):August 2007
DOI:10.1016/j.cclet.2007.06.013
A sensitive flow injection chemiluminescence method has been developed for the detection of resveratrol in red wine based on the fact that resveratrol can greatly enhance chemiluminescence reaction between KMnO4 and HCHO in sulfuric acid medium. Analytes were pre-concentrated on solid sorbents (C18 solid-phase extraction cartridges). Under the optimum conditions, the proposed method allows the measurement of resveratrol over the range of 1.32 × 10−8 to 1.32 × 10−5 mol/L with a detection limit of 3.30 × 10−9 mol/L, and the relative standard deviation for 1.32 × 10−5 mol/L resveratrol (n = 11) is 3.8%. This method has been successfully applied for the determination of the resveratrol in red wine. Furthermore, the possible reaction mechanism was also discussed.
Co-reporter:Haiyan Liu;Yuhong Hao;Pingang He;Juanjuan Ren;Yuzhi Fang
Luminescence 2007 Volume 22(Issue 4) pp:302-308
Publication Date(Web):30 APR 2007
DOI:10.1002/bio.963
A sensitive, simple and rapid flow-injection chemiluminescence (FI–CL) method is described to determine tsumacide pesticide residue based on the CL reaction of the alkaline degradation product of tsumacide with acidic KMnO4 when rhodamine 6G was present. Under the optimum conditions, the relative CL intensity is linear with the concentration of tsumacide in the range of 2.0 × 10−3–0.20 mg/L. The detection limit is 6.6 × 10−4 mg/L (3σ) and the relative standard deviation for 2.0 × 10−2 mg/L tsumacide solution was 2.28% (intra-day) and 4.85% (inter-day). The proposed method has been applied to determine the residue of tsumacide in vegetable samples and the recovery test is very satisfactory. Copyright © 2007 John Wiley & Sons, Ltd.
Co-reporter:Haiyan Liu, Juanjuan Ren, Yuhong Hao, Pingang He, Yuzhi Fang
Talanta 2007 Volume 72(Issue 3) pp:1036-1041
Publication Date(Web):15 May 2007
DOI:10.1016/j.talanta.2006.12.048
A simple, sensitive and selective flow injection-chemiluminescence method for the determination of sulfadiazine in compound naristillae has been investigated. It is based upon the chemilimunescence reaction of sulfadiazine, formaldehyde and potassium permanganate in polyphosphate acid medium. The optimum conditions for the chemiluminescence emission were investigated. Under the optimum conditions, the linear range for the determination of sulfadiazine was 8.0 × 10−7 to 2.0 × 10−4 mol/L with a detection limit of 2.0 × 10−7 mol/L calculated as proposed by IUPAC and a relative standard deviation of 2.53% for 11 solutions of 5.0 × 10−5 mol/L sulfadiazine on the same day. It was also found that the coexisting ephedrine hydrochloride did not interfere with this determination. This led to the successful application of the proposed method for the direct and selective determination of sulfadiazine in compound naristillae.
Co-reporter:Jing Zheng;Li Lin;GuiFang Cheng;AnBao Wang
Science China Chemistry 2007 Volume 50( Issue 3) pp:351-357
Publication Date(Web):2007 June
DOI:10.1007/s11426-007-0062-4
This paper presents a high specific, sensitive electrochemical biosensor for recognition of protein such as thrombin based on aptamers and nano particles. Two different aptamers were chosen to construct a sandwich manner for detecting thrombin. Aptamer I was immobilized on nano magnetic particle for capturing thrombin, and aptamer II labled with nano gold was used for detection. The electrical current generated from gold after the formation of the complex of magnetic particle, thrombin and nano gold, and then an electrochemical cell designed by ourselves was used for separating, gathering, and electrochemical detecting. Through magnetic separation, high specific and sensitive detection of the target protein, thrombin, was achieved. Linear response was observed over the range 5.6×10−12−1.12×10−9 mol/L, with a detection limit of 1.42×10−12 mol/L. The presence of other protein as BSA did not affect the detection, which indicates that high selective recognition of thrombin can be achieved in complex biological samples such as human plasma.
Co-reporter:Jing Zheng, Wanjuan Feng, Li Lin, Fan Zhang, Guifang Cheng, Pingang He, Yuzhi Fang
Biosensors and Bioelectronics 2007 Volume 23(Issue 3) pp:341-347
Publication Date(Web):31 October 2007
DOI:10.1016/j.bios.2007.04.015
An ultrasensitive and highly specific electrochemical aptasensor for detection of thrombin based on gold nanoparticles and thiocyanuric acid is presented. For this proposed aptasensor, aptamerI was immobilized on the magnetic nanoparticles, aptamerII was labeled with gold nanoparticles. The magnetic nanoparticle was used for separation and collection, and gold nanoparticle offered excellent electrochemical signal transduction. Through the specific recognition for thrombin, a sandwich format of magnetic nanoparticle/thrombin/gold nanoparticle was fabricated, and the signal amplification was further implemented by forming network-like thiocyanuric acid/gold nanoparticles. A significant sensitivity enhancement had been obtained, and the detection limit was down to 7.82 aM. The presence of other proteins such as BSA and lysozyme did not affect the detection of thrombin, which indicates a high specificity of thrombin detection could be achieved. This electrochemical aptasensor is expected to have wide applications in protein monitoring and disease diagnosis.
Co-reporter:Zhu Chang, Jingming Zhou, Kun Zhao, Ningning Zhu, Pingang He, Yuzhi Fang
Electrochimica Acta 2006 Volume 52(Issue 2) pp:575-580
Publication Date(Web):25 October 2006
DOI:10.1016/j.electacta.2006.05.036
A sensitive electrogenerated chemiluminescence (ECL) detection of DNA hybridization, based on tris(2,2′-bipyridyl)ruthenium(II)-doped silica nanoparticles (Ru(bpy)32+-doped SNPs) as DNA tags, is described. In this protocol, Ru(bpy)32+-doped SNPs was used for DNA labeling with trimethoxysilylpropydiethylenetriamine(DETA) and glutaraldehyde as linking agents. The Ru(bpy)32+-doped SNPs labeled DNA probe was hybridized with target DNA immobilized on the surface of polypyrrole (PPy) modified Pt electrode. The hybridization events were evaluated by ECL measurements and only the complementary sequence could form a double-stranded DNA (dsDNA) with DNA probe and give strong ECL signals. A three-base mismatch sequence and a non-complementary sequence had almost negligible responses. Due to the large number of Ru(bpy)32+ molecules inside SNPs, the assay allows detection at levels as low as 1.0 × 10−13 mol l−1 of the target DNA. The intensity of ECL was linearly related to the concentration of the complementary sequence in the range of 2.0 × 10−13 to 2.0 × 10−9 mol l−1.
Co-reporter:Haiyan Liu, Ling Zhang, Yuhong Hao, Qingjiang Wang, Pingang He, Yuzhi Fang
Analytica Chimica Acta 2005 Volume 541(1–2) pp:185-190
Publication Date(Web):13 June 2005
DOI:10.1016/j.aca.2005.02.078
A rapid and sensitive flow-injection chemiluminescence method is described for the determination of meloxicam based on its reaction with N-bromosuccinimide (NBS) in alkaline medium. Under the optimum conditions, the proposed method allows the measurement of meloxicam over the range of 2.2 × 10−7 to 2.8 × 10−5 mol/l with a detection limit of 7.7 × 10−8 mol/l. The relative standard deviation for 11 parallel measurements of 2.8 × 10−6 mol/l meloxicam is 2.14%. The method has been applied satisfactorily to the determination of meloxicam in pharmaceutical preparations. The results agree well with those obtained by spectrophotometry. The mechanism of the chemiluminescence reaction is briefly explained with spectroscopic evidence.
Co-reporter:Fan Zhang, Ying-Ying Zhao, Hong Chen, Xiu-Hua Wang, Qiong Chen and Pin-Gang He
Chemical Communications 2015 - vol. 51(Issue 30) pp:NaN6616-6616
Publication Date(Web):2015/02/18
DOI:10.1039/C5CC00428D
A new series of photoactive metallocyclodextrins with increased fluorescence intensity upon binding with ssDNAs/aptamers has been demonstrated to sensitively and selectively detect lysozyme. The detection mechanism relies on the formation of an aptamer–lysozyme complex, which leads to reduction of fluorescence intensity.
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