Construction of plasmonic nanocavity and their application in surface-enhanced Raman scattering

Surface-enhanced Raman scattering(SERS)technology has attracted significant attention and applications in various fields due to its high sensitivity, fingerprinting properties and nondestructive properties. Metal nanostructures form nano-sized gaps(nanocavity)as an important part of the SERS technique, and their morphology, composition and spacing determine the sensitivity and stability of SERS spectra. Therefore, the construction of high-quality plasmonic nanocavity has attracted much attention. The aim of this paper is to review the construction methods of nanocavity and the applications in SERS. Firstly, it introduces the principles of SERS enhancement. Secondly, the methods of preparing highly sensitive, tunable and uniform nanocavity are classified and discussed, including hydrophobic substrate self-shrinkage, two-step photo-reduction, template, self-assembly, and strain-induced cracking, etc. Thirdly, the applications of SERS technology in the fields of food safety, environmental health, and biomedicine are introduced. Finally, the future prospect of SERS technology is outlooked, pointing out the potential value of its applications and challenges in different fields.