Electrochemical sensor based on polyaniline nanofibers/single wall carbon nanotubes composite for detection of malathion

Abstract Detection of malathion (organophosphorous pesticide) based on composite of polyaniline nanofiber and single walled carbon nanotube deposited onto graphite electrode was investigated. >Fourier transforms infrared and UV–vis absorption spectra, X-ray diffraction, scanning electron microscope and cyclic voltammetry were used to characterize the prepared polyaniline. Malathion concentration was detected using differential pulse voltammetry technique at polyaniline–single wall carbon nanotubes modified graphite electrode. The fabricated polyaniline–single wall carbon nanotubes modified graphite electrodes have exhibited higher accuracy toward the reduction of malathion. Malathion was found to exhibit one well-defined reduction peak at pH 7. A linear response to malathion in the concentration range from 2.0 × 10 −7 M to 14.0 × 10 −7 M was observed. The minimum detection limit in the linear range for the modified electrodes was 2.0 × 10 −7 M malathion. It was found that the single wall carbon nanotubes improved the sensitivity of the polyaniline salt graphite electrode from 5.4 mA/μM for polyaniline salt to 7.22 mA/μM.