Rapid and sensitive detection of methyl-parathion pesticide with an electropolymerized, molecularly imprinted polymer capacitive sensor

Abstract

Capacitive detection of methyl-parathion (MP) was carried out on a polyquercetin (Qu)–polyresorcinol (Re)–gold nanoparticles (AuNPs) modified electrode using a molecular imprinting technique and electropolymerization method. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) measurements were used to monitor the process of electropolymerization. Uncovered surface areas were plugged with dodecanethiol to make the layer dense, and the insulating properties of the layer were studied in the presence of [Fe(CN) 6] 3−/[Fe(CN) 6] 4− redox couples and by the use of AC impedance measurements. The template molecules and the non-bound thiol were removed from the molecularly imprinted polymer film capacitance sensor surface with an acidic solution of ethanol. The sensor's linear response range was between 7 × 10 −8 mol L −1 and 1 × 10 −6 mol L −1, with a detection limit of 3.4 × 10 −10 mol L −1. The presented research provides a fast, sensitive and real-time method for detecting organophosphate pesticides. In water and in organic samples, the modified electrode has good anti-interference capabilities and stability (distilled water, tap water, river water, and rain water samples all have good recovery). Moreover, the MIPC sensor can detect MP on fruit surfaces within 72 h after spraying pesticides.