Ali A. Ensafi, Rasool Noroozi, Navid Zandi-Atashbar, B. Rezaei

Fenitrothion is one of the common organophosphorus pesticides that is widely employed for insect control in agriculture. Here, cerium oxide@reduced graphene oxide nanocomposite (CeO₂/rGO) was successfully prepared to apply as an efficient electrocatalyst for electrochemical detection of fenitrothion. The CeO₂/rGO nanocomposite was characterized by various analytical methods including FT–IR spectroscopy, X–ray diffraction spectroscopy and electrochemical techniques. Also, the morphology and characteristic of CeO₂/rGO were monitored using microscopic images of TEM and AFM. CeO₂/rGO was employed to modify glassy carbon electrode (GCE) and resulting data was compared to unmodified GCE and some other reported sensors in literature. The electrochemical studies represented that CeO₂/rGO improved the GCE by decreasing the working potentials to more acceptable one (around 0.00 V vs. Ag/AgCl) with the observable increases in the voltammetric responses towards fenitrothion concentration. The quantitative data were obtained using differential pulse voltammetry (DPV) with a linear range of 0.025 – 2.00 µmol L^–1 fenitrothion. Moreover, its detection limit was obtained as 3.0 nmol L^–1 fenitrothion. Finally, CeO₂/rGO–GCE represented high selective sensing towards fenitrothion in the presence of common interference species present in real well water and spring water samples provided from the agricultural environment.

Keywords: Cerium oxide nanoparticles; Reduced graphene oxide; Fenitrothion;