Sandwich Au/SMSiO2/Ag hybrid substrate: synthesis, characterization, and surface-enhanced Raman scattering performance

Surface-enhanced Raman scattering (SERS) has been considered a high sensitivity, specificity, and ultra-fast analytical technique in molecular fingerprint recognition. Herein, a kind of sandwich Au/“star-like” mesoporous SiO 2 /Ag (Au/MSiO 2 /Ag) hybrid nanostructure was developed by implementing the electrostatic adsorption and magnetron sputtering technology for SERS application. In the experiment, the decoration density of the MSiO 2 /Ag nanostructure was conveniently adjusted through tuning the washing times of the silicon wafer in ethanol. The prepared substrate with the optimal geometry structure exhibited an enhancement factor (EF) of 9.2 × 10 5 , a limit of detection (LOD) of 5 × 10 −5  M, and a low relative standard deviation value of 5.02%. In the end, the obtained hybrid SERS substrate was used to detect nitrofurazone and an excellent LOD of 1 ppm was achieved. Overall, our novel sandwich Au/MSiO 2 /Ag hybrid SERS substrate provides a rapid and accurate way of monitoring ultra-low trace antibiotics, which can significantly promote food safety. Graphical abstract