A novel methyl parathion electrochemical sensor based on acetylene black–chitosan composite film modified electrode

An electrochemical sensor has been developed for the determination of methyl parathion, which was based on the enhanced redox response of methyl parathion at a novel acetylene black–chitosan composite film modified glassy carbon electrode. The electrochemical behavior of methyl parathion at the sensor was investigated by cyclic voltammetry and differential pulse voltammetry. The redox currents of methyl parathion at the acetylene black–chitosan film electrode were significantly higher than that at the bare electrode. The enhanced redox current of methyl parathion was owned to the nano-porus structure of the composite film and the enlarged effective electrode area. The influences of some experimental conditions on the reduction of methyl parathion were tested and the calibration plot was examined. The results indicated that the differential pulse response of methyl parathion was linear with its concentration in the range of 2.0 × 10 −8 to 1.0 × 10 −4 mol/L with a linear coefficient of 0.993. The detection limit was 2.0 × 10 −9 mol/L (S/N = 3). The high sensitivity and selectivity of the sensor were demonstrated by its practical application to the determination of residual methyl parathion in spiked cabbage sample.