A multi-residue electrochemical biosensor based on graphene/chitosan/parathion for sensitive organophosphorus pesticides detection

A graphene/chitosan/parathion multi-residue electrochemical biosensor was prepared by combining the formation of phosphorylated acetylcholinesterase (AChE) between organophosphorus molecules and AChE as well as the excellent conductivity of graphene, and was used to detect 11 organophosphorus pesticides (OPs) by indirect competitive method. The optical and electrochemical properties of modified electrode were studied by UV–Vis absorption spectroscopy, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The linear detection ranges for 11 organophosphorus molecules are 1–1500 ng⋅mL −1 , with detection limits of 0.012–0.23 ng⋅mL −1 , which indicates satisfactory repeatability and stability and can realize quantitative detection of organophosphorus molecules with high sensitivity. The accuracy of chlorpyrifos or dichlorvos detection in real apple samples was performed by graphene/chitosan/parathion electrochemical biosensor, which greatly meets the needs of various departments for quantitative detection of organophosphorus pesticides.