Preparation and sensitive SERS properties of sapphire-supported plasmonic Ag/Au hybrid coupled nanoarray

The regulation of surface plasmon properties of noble metal nanostructure has been a hot topic in the field of nanomaterials preparation and its applications. Surface-enhanced Raman Scattering (SERS), as a sensitive surface-interface trace molecule detection tool, strongly depends on the localized surface plasmonic characteristics. However, how to prepare highly sensitive and reproducible SERS substrates is still under difficult. Herein, Ag/Au hybrid coupled films were attached to the sapphire array by chemical method and interface assembly. Sapphire-based Ag/Au hybrid coupled nanoarrays (SA-Ag/Au HCNAs) with high SERS activity and plasmonic photocatalytic properties were obtained. By monitoring the catalytic reaction of PNTP on the substrate, we found that the prepared SA-Ag/Au HCNAs had significant plasmonic photocatalytic properties. The results show that the synergistic enhancement effect of Ag/Au hybrid coupling is 26.661 times higher than that of pure Au and 9.522 times higher than that of pure Ag. Furthermore, crystal violet (CV), Rhodamine 6G (R6G) and malachite green (MG) were selected as probe molecules, exhibiting good SERS stability and sensitivity of SA-Ag/Au HCNAs substrates. This work provides a simple, low-cost and scalable method for the preparation of hybrid coupled nanoarrays, showing good prospect in photocatalytic dye degradation, environmental monitoring and biomedical analysis.