Novel Electrochemical Sensing Strategy for Organophosphorus Pesticide Residues

Organophosphorus pesticide residues (OPPs) pose significant threats to ecological systems and human health, and conventional detection techniques are cumbersome, time-consuming, and costly. Herein, a facile electrochemical biosensor has been constructed based on a methyl green/chitosan (MG/Chi) composite membrane-modified electrode for the selective detection of OPPs, using isazofos (Isa) as the model analyte. Experimental results demonstrated that Isa significantly decreases the redox peak current of the modified electrode in buffer solution, and a good linear relationship was observed between the change in peak current and Isa concentration within a specific range. This biosensor exhibits excellent anti-interference capability and high sensitivity, with a limit of detection (LOD) as low as 0.60 μM. Furthermore, it was successfully applied for the quantitative determination of OPPs in real food and environmental samples, which confirms its reliable practical applicability and potential for on-site monitoring.