Plant-derived zirconia nanoparticles from Syzygium cumini Lam. leaf extract for the ultrasensitive electrochemical detection of endocrine disruptor bisphenol-A

Abstract

Bisphenol A (BPA) is one of the organic pollutants that disrupt the functioning of hormones, which can significantly disrupt the normal operation of the pituitary-adrenal and hypothalamus-pituitary-gonadal glands. It can downregulate T lymphocytes and antioxidant genes because of its immune-suppressive properties. Thus, the impact of BPA must be quickly identified and eliminated owing to its significant genotoxic and cytotoxic effects. This study explores the eco-friendly synthesis of zirconia (ZrO₂) nanoparticles and their utilization in the development of an electrochemical biosensor for BPA detection. The ZrO₂ nanoparticles are synthesized via a green approach and subsequently characterized using various analytical techniques, including PXRD, SEM, EDS, UV-visible (UV-vis) absorption spectroscopy, FTIR spectroscopy, and AFM, and their electrochemical sensing behaviour is investigated. XRD analysis reveals mixed tetragonal/cubic phases with an average grain size of 2 nm, and the UV-vis absorption result exhibits an optical band-gap of ∼4.6 eV. For BPA detection, an electrochemical biosensor is fabricated by depositing the ZrO₂ nanoparticles onto bare ITO electrodes and then immobilizing them with the tyrosinase enzyme. Electrochemical analysis demonstrates the high sensitivity and selectivity of the biosensor towards BPA, exhibiting a linear range of 50–700 μM, a low detection limit, and a rapid response time (45 s). The fabricated device maintains stability for 40 days when stored at 4 °C and shows reusability for up to 18 scans. Interference studies confirm BPA selectivity in the presence of common interfering compounds. Eco-friendly synthesis, cost-effectiveness, and favourable analytical performance make the ZrO₂ nanoparticle-based biosensor a promising tool for practical applications in environmental monitoring and food safety testing for BPA.