Zhang Weiying, Ding Jiawang, Qin Yuehua, Liu Deli, Du Dan
Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079, PR China.
J Nanosci Nanotechnol. 2010 Sep;10(9):5685-91. doi: 10.1166/jnn.2010.2476.
In this study, an interface embedded in situ gold nanoparticles (AuNPs) and biotin in chitosan hydrogel was constructed by one-step electrochemical deposition in solution containing tetrachloroauric (III) acid, biotin and chitosan. This deposited interface acts as biosensing platforms and provides specific binding sites for avidin, which are further capable of attaching any biotinylated bimolecular for biosensor design. Atomic force microscopy (AFM), A.C. impedance and surface plasmon resonance were used to characterize this interface. The immobilized acetylcholinesterase (AChE), as a model, showed excellent activity to its substrate and provided a quantitative measurement of organophosphate pesticide. Under the optimal experimental conditions, the inhibition of dimethoate was proportional to its concentrations in the range of 0.05 to 15 microg mL(-1) with detection limit of 0.001 microg mL(-1). The simple method showed good fabrication reproducibility and acceptable stability, which provided a new avenue for electrochemical biosensor design.
在本研究中，通过在含有氯金酸（III）、生物素和壳聚糖的溶液中一步电化学沉积，构建了一种原位嵌入壳聚糖水凝胶中的金纳米颗粒（AuNPs）和生物素的界面。该沉积界面作为生物传感平台，为抗生物素蛋白提供特异性结合位点，进而能够连接任何生物素化的双分子用于生物传感器设计。利用原子力显微镜（AFM）、交流阻抗和表面等离子体共振对该界面进行表征。以固定化乙酰胆碱酯酶（AChE）作为模型，其对底物表现出优异的活性，并能对有机磷农药进行定量测定。在最佳实验条件下，乐果的抑制率与其浓度在0.05至15μg mL⁻¹范围内成正比，检测限为0.001μg mL⁻¹。该简单方法具有良好的制备重现性和可接受的稳定性，为电化学生物传感器设计提供了一条新途径。
