SERS Application of Noble Metal–Metal Oxide Hybrid Nanoparticles

Abstract The controlled synthesis of nanohybrids composed of noble metals such as Au, Ag, Pt, and Pd, as well as combinations of these noble metals (core shell, Janus, alloy, etc.) with metal oxides such as ZnO, TiO 2 , Fe 2 O 3 , SiO 2 , etc. have received considerable attention for applications in the fields of photocatalysis, photovoltaics, drug delivery, sensing, and surface-enhanced Raman scattering (SERS), along with the other applications. The morphological characteristics of these materials is one of the most important factors which govern the physical properties of nanohybrids. Noble metals can be coupled to metal oxides to achieve diversified nanostructures, including noble metal decorated-metal oxide nanoparticles, nanoarrays, noble metal–metal oxide core–shell, and Janus noble metal–metal oxide nanostructures. In this chapter, the focus is on the significant advances in tailored nanostructures of noble metal–metal oxide nanohybrids mainly for the SERS applications. The improvement in performance in the representative SERS applications, including the role of morphology and their correlation with the enhancement factor, reusability, and the analyte detection in trace concentrations along with the detailed Raman signal enhancement mechanisms are discussed. Finally, the conclusion has been made with a perspective on the future direction illustrating the prospects of these controllable noble metal–metal oxide-based hybrids in SERS-based applications.