Methyl parathion sensors based on gold nanoparticles and Nafion film modified glassy carbon electrodes

Gold nanoparticles were electrochemically deposited on a Nation film coated glassy carbon electrode to prepare a sensor for determining methyl parathion. The electrochemical behaviours of methyl parathion at the sensor based on gold nanoparticles and Nation film modified glassy carbon electrodes were studied by cyclic voltammetry. The microscopic network structure of Nation provides so much scope that Au nanoparticles can infiltrate into it to enhance ionic and electronic conduction and makes them nanosized. Gold nanoparticles possess extreme small size, a high surface-to-volume ratio and high electrocatalytic activity towards the reduction of methyl parathion. The experimental parameters were optimized, and square wave voltammetry for determining methyl parathion was developed. The irreversible reduction peak current of methyl parathion was proportional to the concentration of methyl parathion over the range of 5.0 x 10(-7) to 1.2 x 10(-4) M with the detection limit of 1.0 x 10(-7) M. The presented method was applied to determining methyl parathion in real samples of water and different vegetables. The sensors for methyl parathion exhibit high sensitivity and good reproducibility and are promising for fast, simple, and sensitive analysis of OPs in environmental and biological samples. (C) 2009 Elsevier B.V. All rights reserved.