Abstract

The present study introduced a novel ion-pair complex of Co(5,5´-dmbpy)3Ce(NO3)6 (a1) fabricated by the reaction of Co(NO3)2·6H2O, Ce(NO3)3·6H2O, NaNO3 and 5,5´-dimethyl-2,2´-bipyridine ligand. A sonochemical method was used to synthesize the nano-scale Co(5,5´-dmbpy)3Ce(NO3)6 (a2). The sulfite was then detected and quantified on a carbon paste electrode (CPE) modified with ferrocene derivative and cobalt nanoparticles (Co-NPs). Scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) were employed to characterize the Co-NPs. The results showed a significant improvement in the electrocatalytic activity and electro-active surface area following the CPE surface modification with the ferrocene derivative and Co-NPs. The voltammetric detection of sulfite was performed successfully by the as-fabricated sensor in real samples, with the linear dynamic range and the limit of detection of 0.07–440.0 and 0.03 µM, under optimal conditions, respectively. © 2022, The Author(s), under exclusive licence to Shiraz University.