Rapid and Sensitive SERS Detection of Bisphenol A via Using Hybrid Si Nanoparticle/Au Nanoparticle on Glass Substrates

A novel hybrid Structures plasmonics sensor of Au Nanoparticles/ Si Nanoparticles configuration (Si@Au NPs) for effectively sensing bisphenol A (BPA) was extensively synthesized and investigated. The microporous silicon was created via laser-assisting etching method with 30mW/cm² and 530 nm laser intensity and wavelength in an etching solution of 1:2 volumetric mixing ratio of 40% Hydrofluoric Acid (HF) of ethanol(C₂H₅OH) with 20 mA/cm² and 10 min etching current density and time respectively. The hybrid structure was produced by electrodeless ion reduction of hydrogen bonds of silicon nanoparticles through 0.005 M HAuCl₄ solution for 3 min. The characterization of Si Nanoparticles and the sensing performance of hybrid structures plasmonics sensors have been inspected by FE-SEM (Field Emission Scanning Electron Microscopes), HR-TEM (High-Resolution Transmission Electron Microscopy), XRD(X-ray diffraction), and Raman microscopy. The performance of the hybrid Structures sensor was investigated with BPA concentrations ranging from 10^–3, 10^–5, 10^–6, 10^–7, and10⁻⁸ M. The fabricated sensor, exhibits, a very low Detection Limit (DL) with excellent reproducibility with the lowest variation of 10^–10 M and 1.6% correspondingly, owing to the higher specific surface area extraordinary density of Si@Au NPs in addition to the huge surface of hot spot districts. The isolated Si@Au NPs hybrid structures sense the ultra-low BPA concentrations lower than the European Union acceptable of about (2.6 μM).