A silver-graphene modified acetylcholinesterase biosensor for detecting organophosphate pesticides

A highly sensitive, stable electrochemical acetylcholinesterase biosensor with silver-graphene modified was fabricated to detect organophosphorus pesticides, dichlorvos. Complete production and test process were characterized by scanning electron microscopy, cyclic voltammetry, differential pulse voltammetry. The electrochemical signal of biosensor got to be well amplified because of the modification of silver-graphene. The better detection performance was got, compared with the sensors that lack or no modified. Moreover, TiO2 sol-gel and high viscous chitosan were used as a highly efficient immobilization matrix for immobilizing acetylcholinesterase. The detection linear range of the biosensor to dichlorvos, a model organophosphorus pesticides compound, was from 0.036 μM (7.9 ppb) to 22.6 μM, with a limit of detection of 7.4 nM (1.6 ppb). The biosensor was highly reproducible and stable in detection and storage.