Development of a Flexible Biosensor based on Green-Synthesized Hematite–Graphene Oxide Nanocomposites for Electrochemical Detection of Bisphenol A

Bisphenol A (BPA), a hazardous endocrine disruptor with strong estrogen-like effects, has raised environmental and health concerns. Therefore, it is crucial to develop an approach that is greener, simpler, cost-effective, flexible, environmentally friendly and efficient for detecting BPA. This work introduces a user-friendly electrochemical sensing platform to detect BPA, utilizing hematite nanoparticles (α-Fe₂O₃NPs) combined with reduced graphene oxide (rGO) on a carbon cloth substrate. Green synthesis, facilitated by Cinnamomum tamala leaf extract, produced α-Fe₂O₃NPs, which were subsequently integrated with graphene oxide to form reduced graphene oxide (rGO), which served as a stabilizing as well as a reducing agent for α-Fe₂O₃NPs. The sensing surface was prepared using electrophoretic deposition, resulting in a nanostructure with superior conductivity and a high surface area, enhancing its electrochemical response on carbon cloth (CC) (i.e., α-Fe₂O₃NPs@rGO/CC) owing to the synergistic effect. The α-Fe₂O₃NPs@rGO/CC sensor exhibited remarkable performance, including a wide detection range (from 1.9 × 10⁻¹⁰ to 1.00 μM), high sensitivity (33.04 μA (log μM)⁻¹ cm⁻²), and the lowest detection limit (0.23 μM), alongside excellent reproducibility, stability, as well as selectivity, ultimately providing satisfying outcomes. Moreover, the sensor was validated using real-world samples, i.e., food and environmental samples confirmed its applicability, paving the way for detecting other similar environmental contaminants.