▎ 摘　　要

An acetylcholinesterase (AChE) biosensor was successfully fabricated with a stable structure and high detection accuracy. Graphene (Gra) nanofragments modified with chitosan (CS) and AChE were successively drip coated on the surface of a glassy carbon electrode via a layer-by-layer assembly method. The concentration range of the sensor to detect dichlorvos was 0.1-100,000 nM, and the limit of detection was 54 pM. CS was used to modify Gra for the first time, which enhanced the mechanical flexibility of these Gra nanostructures, significantly improving the stability and detection accuracy of this sensor.