Electrochemical sensor based on polyaniline supported CdS/CeO2/Ag3PO4 nanocomposite for Malathion detection

Abstract

Different nanomaterials in single (CeO₂), binary (CdS/CeO₂ and Ag₃PO₄/CeO₂), ternary CdS/CeO₂/Ag₃PO₄ (4:1 molar ratio) and conductive polymer supported (PANI-CdS/CeO₂/Ag₃PO₄) were synthesized by co-precipitation method. Elemental analysis, crystal structure, surface area, morphology and optical properties of the as-synthesized nanoparticles were characterized. Electrochemical behavior of glassy carbon electrode modified by polyaniline supported CdS/CeO₂/Ag₃PO₄ nanocomposite were also characterized by electrochemical impedance spectroscopy and cyclic voltammetry in 0.1 M of K₃[Fe(CN)₆] containing 0.1 M KCl at pH 7 with a frequency range of 0.1 to 1000 Hz, with an amplitude of 50 mV. The voltammogramm shows that the process of all as synthesized nanocomposites modified glassy carbon electrode is diffusion controlled. Under optimum conditions, the electrochemical sensor showed Malathion concentrations in linear range of 1-13 $\times$ 10⁻⁷ M, good reproducibility, and no interference by other pesticides and high recovery values around 98.90%. As-synthesized nanocomposite modified glassy carbon electrode exhibits the lowest detection limit of 3.0 $\times$ 10⁻⁹ M for Malathion detection. The simplicity of preparation, high sensitivity, good stability and reproducibility of this nanostructured polyaniline supported CdS/CeO₂/Ag₃PO₄ electrode can be a potential candidate for application in the detection of Malathion.