Sensitive and Selective Electrochemical Detection of Bisphenol A Using Chitosan-Coated Magnetic Nanoparticles

Bisphenol A (BPA) is an endocrine-disrupting compound commonly found in plastics and food packaging. Its potential health risks highlight the need for sensitive and selective electrochemical detection methods, which are often lacking in current approaches. In this study, hybrid chitosan-based magnetic nanoparticles (MNP-CHT) were developed for BPA electrochemical sensing using a magnetic carbon paste electrode (MCPE). MNP was synthesized via a co-precipitation method, followed by surface modification with chitosan (CHT) to produce MNP-CHT. The material was characterized using FTIR, XRD, and FESEM. The electrochemical behaviour of BPA on MNP-CHT MCPE was investigated under different pH levels and scan rates, revealing a two-electron, two-proton transfer mechanism. Differential pulse voltammetry (DPV) enabled BPA detection within a linear range of 0.02–60 μM, with a detection limit of 7.83 nM. The sensor demonstrated excellent reusability for up to five cycles, good long-term stability over 21 days, and strong reproducibility. It also showed high selectivity and anti-interference performance against common BPA analogues, including bisphenol-S (BPS), bisphenol-AF (BPAF), and tetrabromo bisphenol-A (TBBPA). Finally, the MNP-CHT sensor was successfully validated in real samples including tap water, apple juice, and baby teether extract, achieving good recoveries in all cases. These findings confirm the potential of the proposed sensor for sensitive, selective, and reliable BPA detection in environmental, food safety, and consumer product monitoring.