中文摘要：

基于生物催化纳米金的生成和纳米金粒子电催化银沉积实现两次信号放大的原理，构建了一种快速、灵敏的乙酰胆碱酯酶电化学传感器，用于检测有机磷农药。固定在金电极表面的乙酰胆碱酯酶催化底物氯化乙酰硫代胆碱产生硫代胆碱，硫代胆碱还原氯金酸生成纳米金，将电极置于1．0mol／LNH3-．0X10^-3mol／LAgNO，的银增强液中，由于纳米金粒子的催化作用，在-0．10V的电压下，银只会沉积在生成的纳米金表面，沉积银的量与生成的纳米金颗粒的数目成正比，通过线性扫描伏安法定量检测沉积的银。在0．1．1000μg／L范围内，乙酰胆碱酯酶的抑制剂马拉硫磷的浓度与银的溶出峰呈线性，线性方程为ipa=149．9—40．491gC（r-=0．9963），检出限为0．05μg／L。本方法极大地提高了传感器检测的灵敏度。将其应用于湘江水

英文摘要：

A novel, fast and sensitive electrochemical biosensor based on biometallization and silver- enhancing for continuous signal amplification was described for the detection of organophosphate pesticide （OP）. Malathion was used as a model to confirm our strategy. In this method, the immobilized acetylcholinesterase （ACHE） mediated the hydrolysis of acetylthiocholine （ATC1） to yield a reducing agent thiocholine which reduced AuC14- to form gold nanopartieles （AuNPs）. The electrode was then immersed in the silver enhancer solution containing 1.0 mol/L NH3 and 2.0xl0 3 mol/L AgNO3, and under the condition of （1）. 10 V as deposition potential, the metal silver was only deposited on the surface of AuNPs instead of the electrode surface for continuous signal amplification. The deposited silver was then quantified by linear sweep voltammetry （LSV）. In the presence of malathion, the decrease in the stripping peak currents of silver was proportional to the concentration of malathion from 0.1 μg/L to 1000 μg/L, and the linear equation is ipa = 149.9-40. 491℃ （r=0.9963）. The detection limit was found to be as low as 0.05 μg/L. The utilization of biometallization and silver deposition for continuous signal amplification to detect OP dramatically enhanced the sensitivity of AChE electrochemical biosensors. The sensor has been applied to analysis of OP in the water of Xiangjiang River with a satisfactory recovery rates ranging from 95.5% to 102.2% , showing a great potential for the OP assay.