Xiangyou Wang

Shandong University of Technology, Chang-tien-shih, Shandong Sheng, China

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Publications (33)41.13 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A sensitive amperometric acetylcholinesterase (AChE) biosensor was developed based on the nanocomposite of multi-walled carbon nanotubes (MWCNTs), tin oxide (SnO2) nanoparticles and chitosan (CHIT). Acetylcholinesterase (AChE) and Nafion were immobilized onto the nanocomposite film to prepare AChE biosensor for pesticide residues detection. The morphologies and electrochemistry properties of the surface modification were investigated using cyclic voltammetry, differential pulse voltammetry, and scanning electron microscopy, respectively. Compared with individual MWCNTs-CHIT, SnO2-CHIT and bare gold electrode, this nanocomposite showed the most obvious electrochemical signal in the presence of [Fe(CN)6](3-/4-) as a redox couple. Incorporating MWCNTs and SnO2 into 0.2 % CHIT solution can promote electron transfer, enhance the electrochemical response, and improve the microarchitecture of the electrode surface. All variables involved in the preparation process and analytical performance of the biosensor were optimized. Under optimized conditions, the AChE biosensor exhibited a wide linear range from 0.05 to 1.0 × 10(5 )μg/L and with a detection limit for chlorpyrifos was 0.05 μg/L. Based on the inhibition of pesticides on the AChE activity, using chlorpyrifos as model pesticide, the proposed biosensor exhibited a wide range, low detection limit, good reproducibility, and high stability. Using cabbages, lettuces, leeks, and pakchois as model samples, acceptable recovery of 98.7-105.2 % was obtained. The proposed method was proven to be a feasible quantitative method for chlorpyrifos analysis, which may open a new door ultrasensitive detection of chlorpyrifos residues in vegetables and fruits.
    Bioprocess and Biosystems Engineering 08/2014; · 1.87 Impact Factor
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    ABSTRACT: An electrochemical immunosensor based on interdigitated array microelectrodes (IDAMs) was developed for sensitive, specific and rapid detection of chlorpyrifos. Anti-chlorpyrifos monoclonal antibodies were orientedly immobilized onto the gold microelectrode surface through protein A. Chlorpyrifos were then captured by the immobilized antibody, resulting in an impedance change in the IDAMs surface. Electrochemical impedance spectroscopy was used in conjunction with the fabricated sensor to detect chlorpyrifos. Under optimum conditions, the impedance value change of chlorpyrifos was proportional to its concentrations in the range of 10(0)-10(5) ng/mL. The detection limit was found to be 0.014 ng/mL for chlorpyrifos. The proposed chlorpyrifos immunosensor could be used as a screening method in pesticide determination for the analysis of environmental, agricultural and pharmaceutical samples due to its rapidity, sensitivity and low cost.
    Bioprocess and Biosystems Engineering 08/2014; · 1.87 Impact Factor
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    ABSTRACT: In this study, an acetylcholinesterase (AChE) biosensor with superior accuracy and sensitivity was successfully developed based on interdigitated array microelectrodes (IAMs). IAMs have a series of parallel microband electrodes with alternating microbands connected together. Chitosan was used as the enzyme immobilization material, and AChE was used as the model enzyme for carbaryl detection to fabricate AChE biosensor. Electrochemical impedance spectroscopy was used in conjunction with the fabricated biosensor to detect pesticide residues. Based on the inhibition of pesticides on the AChE activity, using carbaryl as model compounds, the biosensor exhibited a wide range, low detection limit, and high stability. Moreover, the biosensor can also be used as a new promising tool for pesticide residue analysis.
    Bioprocess and Biosystems Engineering 04/2014; · 1.87 Impact Factor
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    ABSTRACT: The CLDHs as enzyme immobilization matrix was applied to construct highly performance-enhanced AChE biosensor. Graphene-gold nanocomposite was dropped on the surface of the glassy carbon electrode, and greatly improved the conductivity of the modified electrode. Amperometric experiments were performed on a workstation by adopt a conventional three electrode system. The obtained biosensor based on enzyme inhibition for determination of pesticide showed a wide linear range and low detection limit.
    Enzyme and Microbial Technology 01/2014; · 2.97 Impact Factor
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    ABSTRACT: An electrochemical aptasensor was developed for the detection of kanamycin based on the synergistic contributions of chitosan-gold nanoparticles (CS-AuNPs), graphene-gold nanoparticles (GR-AuNPs) and multi-walled carbon nanotubes-cobalt phthalocyanine (MWCNTs-CoPc) nanocomposites. The aptasensor was prepared by sequentially dripping CS-AuNPs, GR-AuNPs and MWCNTs-CoPc nanocomposites onto a gold electrode (GE) surface. During the above process, these nanomaterials showed a remarkable synergistic effect towards the aptasensor. CS-AuNPs, GR-AuNPs and MWCNTs-CoPc as the nanocomposites mediator improved electron relay during the entire electron transfer process and the aptasensor response speed. The electrochemical properties of the modified processes were characterized by cyclic voltammetry (CV). The morphologies of the nanocomposites were characterized by scanning electron microscopy (SEM). The experimental conditions such as the concentration of the aptamer, the time, temperature and the pH were optimized. Based on the synergistic contributions of CS-AuNPs, GR-AuNPs and MWCNTs-CoPc nanocomposites, the proposed aptasensor displayed high sensitivity, high specificity, a low detection limit (5.8 × 10(-9) M) (S/N = 3) and excellent stability. It was successfully applied to the detection of kanamycin in real milk spiked samples.
    The Analyst 11/2013; · 4.23 Impact Factor
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    Ying Zhu, Yaoyao Cao, Xia Sun, Xiangyou Wang
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    ABSTRACT: In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs) and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au) nanocomposites were modified onto the surface of a glass carbon electrode (GCE) via self-assembly. The nanocomposites can increase the surface area of the GCE to capture a large amount of antibody, as well as produce a synergistic effect in the electrochemical performance. Then the modified electrode was coated with gold nanoparticles-antibody conjugate (AuNPs-Ab) and blocked with BSA. The monoclonal antibody against carbofuran was covalently immobilized on the AuNPs with glutathione as a spacer arm. The morphologies of the GS-PEI-Au nanocomposites and the fabrication process of the immunosensor were characterized by X-ray diffraction (XRD), ultraviolet and visible absorption spectroscopy (UV-vis) and scanning electron microscopy (SEM), respectively. Under optimal conditions, the immunosensor showed a wide linear range, from 0.5 to 500 ng/mL, with a detection limit of 0.03 ng/mL (S/N = 3). The as-constructed immunosensor exhibited notable performance features such as high specificity, good reproducibility, acceptable stability and regeneration performance. The results are mainly due to the excellent properties of MWCNTs, GS-PEI-Au nanocomposites and the covalent immobilization of Ab with free hapten binding sites for further immunoreaction. It provides a new avenue for amperometric immunosensor fabrication.
    Sensors 01/2013; 13(4):5286-301. · 2.05 Impact Factor
  • Xia Sun, Chen Zhai, Xiangyou Wang
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    ABSTRACT: The nanocomposite comprised of O-carboxymethyl chitosan (CMCS) and gold nanoparticles (AuNPs) is successfully prepared by in-situ synthesis method. The synthesized nanocomposite has been characterized by scanning electron microscopy images. The CMCS-AuNPs nanocomposite is first modified onto the glassy carbon electrode (GCE), then the surface carboxyl group is activated by N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride. Finally, the acetylcholinesterase (AChE) is immobilized onto the GCE to construct a novel AChE biosensor for the detection of pesticides. Because the nanocomposite was able to inherit the properties of the AuNPs and CMCS, the resulting surface provided a favorable microenvironment for AChE biosensor fabrication and maintained the bioactivity of AChE for screening of pesticide exposure. Based on the inhibition of pesticides on AChE activity using chlorpyrifos as the model compound, the results showed that the inhibition of chlorpyrifos is proportional to its concentration ranging from 0.1 to 20 μg/L and 20 to 100 μg/L, with a detection limit of 0.07 μg/L (S/N=3). The developed biosensor exhibited good reproducibility, acceptable stability, fast response, and low detection limit, thus providing a new promising tool for the rapid detection of pesticides.
    IEEE Sensors Journal 01/2013; 13(1):172-179. · 1.48 Impact Factor
  • Xia Sun, Lu Qiao, Xiaoxu Sun, Xiangyou Wang
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    ABSTRACT: In this reported work, an acetylcholinesterase (AChE) biosensor based on chitosan-Prussian blue-multiwall carbon nanotubes-hollow gold nanospheres (Chit-PB-MWNTs-HGNs) film was used for detecting pesticide residues in vegetable samples. Three different kinds of sample extraction methods were investigated, such as the oscillation extraction method, the ultrasonication and the centrifugation extraction method and the ultrasonication and filtration extraction method. By comparison, the ultrasonication and centrifugation extraction method was the most appropriate and efficient for the AChE biosensor. After treatment by ultrasonication and centrifugation extraction, the recoveries of the pesticides from vegetable samples were from 76.8 to 105.9% with relative standard deviation lower than 12.68%. Subsequently, the detection results with the AChE biosensor were compared with the standard gas chromatography method. The results indicated that the proposed sample pretreatment method was applicable to the AChE biosensor for pesticide residues detection in real vegetable samples.
    Micro & Nano Letters 01/2013; 8(7):330-335. · 0.85 Impact Factor
  • Xia Sun, Ying Zhu, Xiangyou Wang
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    ABSTRACT: In this paper, a novel label-free amperometric immunosensor for the detection of carbofuran residues was developed. The deposited gold nanocrystals (DpAu)/4,4′-thiobisbenzenethiol (DMDPSE) multilayers ({DpAu/DMDPSE}n) membranes were used for modifying Au electrode to fabricate amperometric immunosensor. DpAu/DMDPSE multilayers were modified alternatively to form multiple membranes by layer-by-layer self-assembly technology. The sensitive steps of surface modification were characterized by cyclic voltammetric (CV) and electrochemical impedance spectroscopy (EIS), respectively. The immunoreaction between anti-carbofuran monoclonal antibody and carbofuran directly triggered a signal via different pulse voltammetry (DPV). Under the optimized conditions, a linear relationship between the relative change in peak current of DPV (%ΔI) and the logarithm of carbofuran solution was obtained in the range from 0.1 to 1.0 × 106 ng/mL with a detection limit of 0.06 ng/mL. The advantages of the immunosensor were exhibited in its wider linear range, better reproducibility, stability, selectivity and regeneration. Using lettuces, cabbages, green peppers, tomatoes, Chinese chives and strawberries as model samples, acceptable recovery of 82.0–109.2% was obtained. The proposed method was proven to be a feasible quantitative method for carbofuran analysis, which may open a new door for ultrasensitive detection of carbofuran residues in vegetables and fruits.
    Food Control. 11/2012; 28(1):184–191.
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    ABSTRACT: In this paper, chitosan-prussian blue-multiwall carbon nanotubes-hollow gold nanospheres (Chit-PB-MWNTs-HGNs) film was fabricated onto the gold electrode surface by one-step electrodeposition method; and then acetylcholinesterase (AChE) and Nafion were modified onto the film to prepare an AChE biosensor. Incorporating MWNTs and HGNs into Chit-PB hybrid film promoted electron transfer reaction, enhanced the electrochemical response and improved the microarchitecture of the electrode surface. The morphologies and electrochemistry properties of the composite were investigated by using scanning electron microscopy, transmission electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. Parameters affecting the biosensor response such as pH, enzyme loading and inhibition time were optimized. Based on the inhibition of pesticides on the AChE activity, using malathion, chlorpyrifos, monocrotophos and carbofuran as model compounds, this biosensor showed a wide range, low detection limit, good reproducibility and high stability. Moreover, AChE/Chit-PB-MWNTs-HGNs/Au biosensor can also be used for direct analysis of practical samples, which would be a new promising tool for pesticide analysis.
    Biosensors & bioelectronics 10/2012; 42C:124-130. · 5.43 Impact Factor
  • Xia Sun, Chen Zhai, Xiangyou Wang
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    ABSTRACT: In this work, a highly sensitive acetylcholinesterase (AChE) inhibition-based amperometric biosensor has been developed. Firstly, a glassy carbon electrode (GCE) was modified with chitosan (Chits). Then, hollow gold nanospheres (HGNs) were absorbed onto the surface of chitosan based on the strong affinity through electrostatic adsorption. After that, L: -cysteine (L: -cys) was assembled on HGNs through Au-S bond. The hollow gold nanospheres were prepared by using Co nanoparticles as sacrificial templates and characterized by scanning electron microscopy, transmission electron microscopy and ultraviolet spectra, respectively. Finally, AChE was immobilized with covalent binding via -COOH groups of L: -cysteine onto the modified GCE. The AChE biosensor fabrication process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy methods with the use of ferricyanide as an electrochemical redox indicator. Under optimum conditions, the inhibition rates of pesticides were proportional to their concentrations in the range of 0.1-150 and 0.1-200 μg L(-1) for chlorpyrifos and carbofuran, respectively, the detection limits were 0.06 μg L(-1) for chlorpyrifos and 0.08 μg L(-1) for carbofuran. Moreover, the biosensor exhibited a good stability and reproducibility and was suitable for trace detection of pesticide residues in vegetables and fruits.
    Bioprocess and Biosystems Engineering 07/2012; · 1.87 Impact Factor
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    ABSTRACT: In this work, a novel amperometric immunosensor based on multi-walled carbon nanotubes-thionine-chitosan (MWCNTs-THI-CHIT) nanocomposite film as electrode modified material was developed for the detection of chlorpyrifos residues. The nanocomposite film was dropped onto a glassy carbon electrode (GCE), and then the anti-chlorpyrifos monoclonal antibody was covalently immobilized onto the surface of MWCNTs-THI-CHIT/GCE using the crosslinking agent glutaraldehyde (GA). The modification procedure was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimized conditions, a linear relationship between the relative change in peak current of different pulse voltammetry (DPV) and the logarithm of chlorpyrifos solution concentration was obtained in the range from 0.1 to 1.0 × 105 ng/mL with a detection limit of 0.046 ng/mL. The proposed chlorpyrifos immunosensor exhibited high reproducibility, stability, and good selectivity and regeneration, making it a potential alternative tool for ultrasensitive detection of chlorpyrifos residues in vegetables and fruits.
    Sensors 01/2012; 12(12):17247-61. · 2.05 Impact Factor
  • Xia Sun, Qingqing Li, Xiangyou Wang
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    ABSTRACT: A new label-free immunosensor for the determination of carbofuran was proposed in this paper. Saturated thiourea (TU) and gold nanoparticles (GNPs) were modified onto the glassy carbon electrode surface to form a GNPs/TU film, which provided an interface containing $\hbox{-}{\rm NH}_{2}$ to assemble the second GNPs for the immobilization of anti-carbofuran antibody. Bovine serum albumin was used for blocking the non-specific adsorption sites. Thus, a novel amperometric immunosensor for carbofuran was prepared. The electrochemical properties of the modified processes were characterized by electrochemical impedance spectroscopy and cyclic voltammetry. Under the optimal conditions, the current response was proportional to the concentration of carbofuran ranging from 1.0 ng/mL to 100.0 ng/mL and from 100.0 ng/mL to 200 $\mu{\rm g}/{\rm mL}$ with the detection limit 0.11 ng/mL. The proposed amperometric immunosensor exhibited high sensitivity, low cost and simplified procedures, which provided a new promising tool for the detection of pesticides residues in food and environment.
    IEEE Sensors Journal 01/2012; 12(6):2071-2076. · 1.48 Impact Factor
  • Shuyuan Du, Xiangyou Wang, Xia Sun, Qingqing Li
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    ABSTRACT: In this study, anti-carbofuran monoclonal antibodies (Ab) were immobilized onto a gold electrode surface modified with multilayers of L-cysteine and gold colloidal nanoparticles (GNPs). Furthermore, horseradish peroxidase (HRP) as enzyme membrane was used for blocking unspecific sites and amplifying signal. The conformational properties of the immunosensor were characterized using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The concentration of antibody solution, pH of working buffer and incubation time were studied in detail for optimization of analytical performance. Under optimal conditions, the variation of current response was proportional to the concentration of carbofuran which ranged from 0.01 ng/mL to 50 ng/mL with correlation coefficient of 0.9912. The detection limit was 0.01 ng/mL (S/N = 3). The proposed immunosensor exhibited good reproducibility and stability and it can be used for the rapid detection of carbofuran pesticide.
    Analytical Letters - ANAL LETT. 01/2012;
  • Xia Sun, Qingqing Li, Xiangyou Wang, Shuyuan Du
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    ABSTRACT: In this paper, a novel amperometric immunosensor for the determination of carbofuran based on gold nanoparticles (GNPs), magnetic Fe3O4 nanoparticles-functionalized multiwalled carbon nanotubes-chitosan (Fe3O4-FCNTs- CS) and bovine serum albumin (BSA) composite film was proposed. Firstly, GNPs were immobilized onto the glassy carbon electrode (GCE) surface, and then the magnetic Fe3O4 nanoparticles mixed with chitosan-functionalized multiwall carbon nanotubes (CS-FCNTs) homogeneous composite (CS-FCNTs-Fe3O4) was immobilized onto the GNPs layer by electrostatic interactions between amino groups of CS and GNPs. Because chitosan (CS) contains many amino groups, it can absorb more antibodies; FCNTs have high surface area, high electrical conductivity, it can enhance electron transfer rate; Magnetite (Fe3O4) nanoparticles can provide a favourable microenvironment for biomolecules immobilization due to their good biocompatibility, strong superparamagnetic property, low toxicity; GNPs opssess high surface-to-volume reaction, stability, and high conductivity. Gold Nanoparticles /Fe3O4-FCNTs-CS composite film was constructed onto the GCE surface, which had significant synergistic effects towards immunoreaction signal amplification. The stepwise assembly process was characterized by cyclic voltammetry (CV) and electrochemical impendance spectroscopy (EIS), respectively. Under the optimal conditions, the current response was proportional to the concentration of carbofuran ranging from 1.0 ng/mL to 100.0 ng/mL and from 100.0 ng/mL to 200 µg/mL with the detection limit 0.032 ng/mL. The proposed immunosensor exhibited good accuracy, high sensitivity and stability, and it can be used for detection of carbofuran pesticide.
    Analytical Letters - ANAL LETT. 01/2012;
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    ABSTRACT: In this study, an anti-carbofuran monoclonal antibody (Ab) was immobilized on the surface of a glassy carbon electrode (GCE) using silica sol-gel (SiSG) technology. Thus, a sensitive, label-free electrochemical immunosensor for the direct determination of carbofuran was developed. The electrochemical performance of immunoreaction of antigen with the anti-carbofuran monoclonal antibody was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), in which phosphate buffer solution containing [Fe(CN)(6)](3-/4-) was used as the base solution for test. Because the complex formed by the immunoreaction hindered the diffusion of [Fe(CN)(6)](3-/4-) on the electrode surface, the redox peak current of the immunosensor in the CV obviously decreased with the increase of the carbofuran concentration. The pH of working solution, the concentration of Ab and the incubation time of carbofuran were studied to ensure the sensitivity and conductivity of the immunosensor. Under the optimal conditions, the linear range of the proposed immunosensor for the determination of carbofuran was from 1 ng/mL to 100 μg/mL and from 50 μg/mL to 200 μg/mL with a detection limit of 0.33 ng/mL (S/N = 3). The proposed immunosensor exhibited good high sensitivity and stability, and it was thus suitable for trace detection of carbofuran pesticide residues.
    Sensors 01/2011; 11(10):9520-31. · 2.05 Impact Factor
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    Xia Sun, Ying Zhu, Xiangyou Wang
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    ABSTRACT: In this paper, an amperometric immunosensor modified with protein A/deposited gold nanocrystals (DpAu) was developed for the ultrasensitive detection of carbofuran residues. First, DpAu were electrodeposited onto the Au electrode surface to absorb protein A (PA) and improve the electrode conductivity. Then PA was dropped onto the surface of DpAu film, used for binding antibody Fc fragments. Next, anti-carbofuran monoclonal antibody was immobilized on the PA modified electrode. Finally, bovine serum albumin (BSA) was employed to block the possible remaining active sites avoiding any nonspecific adsorption. The fabrication procedure of the immunosensor was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), respectively. With the excellent electroconductivity of DpAu and the PA's oriented immobilization of antibodies, a highly efficient immuno-reaction and detection sensitivity could be achieved. The influences of the electrodeposition time of DpAu, pH of the detection solution and incubation time on the current response of the fabricated immunosensor were investigated. Under optimized conditions, the current response was proportional to the concentration of carbofuran which ranged from 1 to 100 ng/mL and 100 ng/mL to 100 μg/mL. The detection limit was 0.1924 ng/mL. The proposed carbofuran immnuosensor exhibited high specificity, reproducibility, stability and regeneration performance, which may open a new door for ultrasensitive detection of carbofuran residues in vegetables and fruits.
    Sensors 01/2011; 11(12):11679-91. · 2.05 Impact Factor
  • Zhanli Liu, Xiangyou Wang
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    ABSTRACT: The design principles, system structure and experimental debugging of high oxygen modified atmosphere box for fresh-cut fruits and vegetables were studied. Compared with gas chromatography, the concentrations measured by the oxygen and carbon dioxide sensor were accurate. Debugging process could be seen. The concentration in the experimental box of O2, CO2 gradually reached the set value. The most significant fluctuation in temperature was less than ± 0.5°C. The most significant fluctuation in relative humidity was less than ± 3%. The most significant fluctuation of O2 concentration in the volume fraction was less than ± 5%. The most significant fluctuation of CO2 concentration was less than ± 2%.
    Electronics, Communications and Control (ICECC), 2011 International Conference on; 01/2011
  • Shuyuan Du, Xia Sun, Xiangyou Wang
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    ABSTRACT: In this study, two kinds of novel label-free amperometric immunosensor for the direct detection of carbofuran was developed using layer-by-layer assembly and sol-gel technology, respectively. In one hand anti-carbofuran monoclonal antibodies were immobilized on the gold electrode (GE) surface which was modified with multilayers of L-cysteinewas, gold nanoparticles (nano-Au) and horseradish peroxidase (HRP) through layer-by-layer assembly technology, in the other hand, anti-carbofuran monoclonal antibodies were immobilized on the surface of the glassy carbon electrode (GCE) based on sol-gel technology to prepare non-labeled electrochemical immunosensor for the detection of carbofuran. The conformational properties of the immunosensor were characterized using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and a current response curve. Effects of experimental variables, such as concentration of antibody solution, pH of working buffer and incubation time, were studied in detail for optimization of analytical performance. Under optimal conditions, the current response was proportional to the concentration of carbofuran.
    01/2011;
  • Xia Sun, Qingqing Li, Xiangyou Wang
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    ABSTRACT: com Abstract -Based on the change in electrochemical behavior of enzymatic activity induced by organophosphates (OP) compounds, a simple electrochemical method has been developed for investigation of Organophosphates (OP) compounds using acetylcholineste rase (AChE) biosensor. Aniline (AN) and multiwall carbon nanotubes (MWNTs) are modified on the surfuce of glassy carbon electrode(GCE). The electrochemical behavior of AChE-AN-MWNTs/GC E was studied, and the results showed the AN-MWNTs promoted electron-transfe r reactions at a lower potential and catalyzed the electro-oxidatio n of thiocholine, thus increasing detection sensitivity. Using dichlorvos as a model pesticide, the biosensor had good linearity in the concentration range of50ngL- 1-1I1gL- 1 and 50I1gL- 1-5mgL- l with a correlation coefficient of 0.9995 and 0.9990, respectively. The detection limit was 10ngL- t. The biosensor exhibited high sensitivity, good reproducibility and stability, and it was suitable for trace detection ofOP pesticide residue.
    01/2011;