Development of electrochemical impedance-based sensor for the detection of pesticides type organophosphate

In this study chlorpyrifos (CPF) templated molecularly imprinted film is electrochemically synthesized on a pencil graphite electrode (PGE) using cyclic voltammetry to electropolymerize pyrrole in the presence of CPF. The fabricated modified electrode was used as a novel impedimetric sensor for the determination of an important organophosphorus pesticide, CPF. The binding performance of CPF to the polypyrrole (PPy) film was examined by using electrochemical impedance spectroscopy. The surface morphology of the imprinted film was characterized by Scanning Electron Microscopy. The results obtained from impedance measurements show that imprinted PPy modified PGE gives renewable, disposable, low cost, selective and sensitive electrochemical sensor for the determination of CPF. Under experimental conditions, the proposed impedimetric sensor has a linear response range between 20 to 300 µg L-1 with detection limit of 5.8 µg L-1 (based on 3sb). Furthermore, the fabricated sensor was successfully applied to determine CPF in spiked samples.