An experimental and theoretical study of molecularly imprinted electrode based on methyl methacrylate polymer for pesticide detection

Abstract

A selective electrode based on molecularly imprinted polymer (MIP) was developed by the polymerization of methyl methacrylate polymer on a screen-printed electrode for pesticide detection. Cypermethrin is one of the pesticides in the pyrethroid group, which has high toxicity in an organism and humans and causes environmental pollution. Cypermethrin-MIP and non-imprinted polymer films on electrodes were characterized for their surface morphology. The electrochemical analysis of cypermethrin pesticide was measured by amperometry under the potential of -0.23 V versus Ag/AgCl. Decreasing the current was directly proportional to the concentration of cypermethrin in the range of 15.50 ppb-10.00 ppm, and the limit of detection value was calculated to be 15.00 ppb. The proposed modified electrode has high sensitivity of 0.094 μA ppm-1 and effective selective detection of cypermethrin in samples of real vegetable juice. The computational analyses were performed with the density functional theory at M06-2x/6-31 g(d,p), which predicted interaction and study mechanism between the MIP matrix with target pesticides.