AuNPs/Sol-gel复合膜法固定乙酰胆碱酯酶生物传感器检测有机磷农药

Determination of Organophosphorus Pesticides Using a Biosensor Based on Acetylcholinesterase Immobilized by Au Nanoparticles/Sol-gel Composite Membrane

基于有机磷农药对乙酰胆碱酯酶(Acetylcholinesterase,AChE)的抑制作用,用金纳米粒子(Au nanopar-ticles,AuNPs)与壳聚糖/SiO2杂化溶胶-凝胶构成复合固酶基质,将AChE固定于玻碳电极表面,制备了电流型AChE生物传感器.选用久效磷进行实验,以氯化硫代乙酰胆碱为底物,建立了电化学测定有机磷农药的分析方法.依据传感器的电流响应值,优化了各种实验条件.该传感器对久效磷进行检测的线性响应范围为0.5～12.0μg/mL,检出限为0.02μg/mL.传感器具有良好的重现性和稳定性,为有机磷农药的检测提供了一种简便易行的方法.

Based on the inhibition effects of organophosphorus pesticides on acetylcholinesterase （ACHE）, an amperomerometric biosensor was developed by immobilizing AChE on glassy carbon electrode with the composite film of Au nanoparticals and chitosan-silica hybrid sol-gel. Using acetylthiocholine chloride as the substrate, the electrochemical determination method for organophosphorus pesticide was established with monocrotophos as a representative model for sensitivity tests. The experimental conditions were optimized according to the current response. The response of biosensor fabricated was related linearly to the concentration of monocrotophos in the range of 0.5--12.0 ug/mL with a detection limit of 0.02 ug/mL. The developed biosensor exhibited good reproducibility and acceptable stability, providing a simple method for the analysis of organophosphorus pesticide.