Electrochemical Sensor for Determination of Fenitrothion at Multi-wall Carbon Nanotubes Modified Glassy Carbon Electrode

A sensor, based on multi-wall carbon nanotubes modified glassy carbon electrode (MWCNT/GCE), was developed for determination of fenitrothion. Determining the surface area of MWCNT/GCE showed that this surface is three times more active than that of a glassy carbon electrode. The experimental parameters, such as the amount of MWCNTs, pH of the fenitrothion solution, preconcentration potential and preconcentration time were optimized. Under these conditions, reduction current showed a linear relationship with the concentration of fenitrothion in a range of 0.01-5.0 mM, with a detection limit of 6.4 nM. The modified electrode also exhibited good stability and reproducibility. The effects of possible interferents were studied and found to be negligible, indicative of high selectivity of the electrode. This sensor was also successfully employed for determination of fenitrothion in soil and Teff samples with recovery values in the range of 88.0-93.3% and 86.7-91.4%, respectively.