One-Step Electrochemically Deposited Gold Nanoparticles Interface Grafted with Avidin for Acetylcholinesterase Biosensor Design
作者:Weiying Zhang、Jiawang Ding、Yuehua Qin、Deli Liu、Dan Du
DOI:10.1166/jnn.2010.2476
日期:2010.9.1
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 μg mL−1 with detection limit of 0.001 μg mL−1. The simple method showed good fabrication reproducibility and acceptable stability, which provided a new avenue for electrochemical biosensor design.
本研究在含有四氯金酸(III)、生物素和壳聚糖的溶液中,通过一步电化学沉积法在壳聚糖水凝胶中构建了嵌入原位金纳米粒子(AuNPs)和生物素的界面。这种沉积界面可作为生物传感平台,为阿维丁提供特异性结合位点,并可进一步连接任何生物素双分子,用于生物传感器的设计。原子力显微镜(AFM)、A.C. 阻抗和表面等离子体共振被用来表征这种界面。以固定化的乙酰胆碱酯酶(AChE)为模型,该酶对其底物表现出极好的活性,并能定量检测有机磷农药。在最佳实验条件下,乙酰胆碱酯酶在 0.05 至 15 μg mL-1 的浓度范围内对二甲戊乐灵的抑制率与其浓度成正比,检测限为 0.001 μg mL-1。这种简单的方法具有良好的制造重现性和可接受的稳定性,为电化学生物传感器的设计提供了一条新途径。