▎ 摘　　要

Highly dispersed zinc oxide nanoparticles (ZnO NPs) were synthesized on carboxylic graphene (CGR). A novel acetylcholinesterase (AChE) biosensor based on ZnO NPs, CGR and Nafion (NF) hybrids modified glass carbon electrode (GCE) has been successfully developed. ZnO NPs-CGR was homogeneously dispersed in NF and dropped on the surface of GCE. ZnO NPs-CGR-NF possessed excellent conductivity, catalysis and biocompatibility which were attributed to the synergistic effects of ZnO NPs, CGR and NF. ZnO NPs-CGR-NF/GCE provided a hydrophilic surface for AChE adhesion. The AChE biosensor showed favorable affinity to acetylthiocholine chloride (ATCl) and could catalyze the hydrolysis of ATCl with an apparent Michaelis-Menten constant value of 126 mu M, which was then oxidized to produce a detectable and fast response. Under optimum conditions, the biosensor detected chlorpyrifos and carbofuran ranging from 1.0 x 10(-13) to 1 x 10(-8) M and from 1.0 x 10(-12) to 1 x 10(-8) M. The detection limits for chlorpyrifos and carbofuran were 5 x 10(-14) M and 5.2 x 10(-13) M, respectively. The developed biosensor exhibited many advantages such as good sensitivity, stability, reproducibility and low cost, thus providing a promising tool for analysis of enzyme inhibitors. This study could provide a universal platform for meeting the demand of the effective immobilization enzyme on the electrode surface. (c) 2013 Elsevier B. V. All rights reserved.