A novel electrochemical sensor for isocarbophos based on a glassy carbon electrode modified with electropolymerized molecularly imprinted terpolymer

In this paper, a novel electrochemical sensor with sensitive and selective binding sites for isocarbophos (ICP) detection is reported, which is based on a glassy carbon electrode (GCE) modified with molecularly imprinted terpolymer of poly(o-phenylenediamine-co-gallic acid-co-m-aminobenzoic acid) (p(PD-GA-ABA)) templated with ICP. The surface feature of the p(PD-GA-ABA) modified GCE (MIP/GCE) was characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Several important parameters controlling the performance of the MIP/GCE were investigated and optimized. Under optimal conditions, the changes in DPV peak currents of the redox probe, hexacyanoferrate, were linear to ICP concentrations in the range from 7.50 x 10(-8) to 5.00 x 10(-5) M and 5.00 x 10(-5) to 1.00 x 10(-4) M, with the detection limit of 2.01 x 10(-8) M (S/N = 3). The method was applied successfully to determine ICP in cabbage and cowpea samples with satisfactory precision (2.30-5.28% of RSD) and acceptable recoveries (95.5-110.0%), demonstrating a promising feature for applying the MIP sensor to the measurement of ICP in real samples. (C) 2012 Elsevier B.V. All rights reserved.