Non-plasmonic Metal Oxide Nanostructures for SERS Applications

Non-plasmonic metal oxide (MeO) nanomaterials have become very promising surface-enhanced Raman scattering (SERS) substrates due to their unique physicochemical properties. Although significantly fewer SERS applications of MeO substrates have been reported so far compared to plasmonic noble metals-based ones, SERS-active MeO platforms have some important advantages. Most importantly, MeO-based nanomaterials provide good biocompatibility, low biotoxicity, good spectral stability, as well as some of them also have strong photocatalytic activity. On the other hand, the main limiting factor for their applications is the low SERS sensitivity. However, as shown in recent studies, this can be substantially improved through rationally tuning resonance conditions for the target analyte and MeO substrate. Moreover, it may be promising to profit from a synergy of both the chemical and electromagnetic enhancement in the case of a combination of MeO materials with plasmonic noble metals. The recent SERS applications of MeO materials include the detection of anions, pesticides, pollutants, biomarkers, and employment in cancer diagnosis. This chapter provides background information on non-plasmonic MeO nanostructures and their SERS-related applications.