Biomodified NiAl LDH for High-Performance Electrochemical Sensing and Degradation of Bisphenol A

Bisphenol A (BPA) is a chemical of increasing concern because of its widespread harmful impacts on the environment and aquatic systems. To address this issue, we synthesized a stearic-acid-modified nickel-aluminum layered double hydroxide with rutin intercalation (Ru@SA-NiAl LDH) for the electrochemical detection of BPA. The excellent reduction in band gap lowers the energy required for electron excitation, thereby improving conductivity and charge transfer at the electrode surface. In the same way, increased roughness in the composite indicates successful Ru loading and provides more active sites, improved surface heterogeneity, and enhanced interaction capability for BPA detection. The [Fe(CN)₆]^3-/4- redox probe validated the electrochemical activity of Ru@SA-NiAl LDH and its suitability for BPA sensing by demonstrating efficient interfacial charge transport, high stability, successful surface modification, enhanced electroactive surface area, and rapid electron-transfer kinetics. In the SWV analysis, rutin (Ru) acts as the electron mediator to shuttle electrons to BPA and hence improves the sensitivity of the Ru@SA-NiAl LDH with a linear range of 10 nM-600 μM. Its LOD is 1.29 nM and serves as a reliable platform of BPA in real-time environmental monitoring. Interestingly, we also performed a degradation study of BPA with different metal ions such as Fe, Cu, and Cr interacting with •OH radicals, oxidatively breaking BPA into phenoxyl radicals, and reducing the amount of electroactive BPA available for oxidation at the electrode. Also, the analysis of the degradation ability with different buffers demonstrated that BPA is deprotonated by phenolate ions, which are nucleophilic and have more reactivity to degrade BPA in NaOH buffer. Overall, Ru@SA-NiAl LDH exhibited outstanding electrochemical sensing and degradation ability.