An efficient electrochemical sensor for determination of sulfite in water and soft drinks based on Ce3+-doped CuO nanocomposite

Abstract

This study addressed the preparation, characterization, and assay of a screen-printed electrode (SPE) modified with the Ce3+ doped-CuO nanocomposite for the voltammetric detection of sulfite ions. Therefore, the dimension of the new nanocomposite and its morphology were verified by characterization analyses such as energy-dispersive X-ray spectroscopy (EDX), scanning electron microscope (SEM) and X-ray diffraction (XRD). According to cyclic voltammetry (CV), the oxidation of the sulfite at the Ce3+-doped CuO/SPE followed an irreversible and diffusion-controlled mechanism. The results indicated that the new electrode exhibited good electrocatalytic activities towards sulfite oxidation, based on which an electrochemical sensor was presented to detect sulfite. In addition, Ce3+-doped CuO/SPE showed a wide linear range between 0.6 and 400 μM with the limit of detection (LOD) of 0.08 μM to detect sulfite. Finally, this new approach was applied for determining sulfite in real samples, reflecting its utility as one of the cheap analytical tools to control product quality.