An Acetylcholinesterase-Functionalized Biosensor for Sensitive Detection of Organophosphorus Pesticides Based on Solution-Gated Graphene Transistors

In this work, a highly sensitive and selective organophosphorus pesticide (OP) biosensor based on a solution-gated graphene transistor (SGGT) has been successfully constructed. The electrochemical performance of the device is improved by immobilization of acetylcholinesterase (AChE) on the gold gate electrode with chitosan (CHIT) for detection of OPs. The AChE/CHIT-functionalized SGGT sensor shows an ultralow detection limit of 10 nM for OPs and a wide linear range from 300 nM to 3 μM. We also proved that the SGGT-based OP sensor has good selectivity and recovery performance for efficient evaluation of the level of OPs in actual rice samples. This sensor provides a promising detection platform for rapid and sensitive analysis of OPs in real samples with complex components and can be readily applied to many other important analytes for agricultural and food safety using the corresponding enzymes.