Nanocavity-based single-molecule plasmon-enhanced Raman spectroscopy: Features and advancements

Since 1997, driven by advancements in nanoscience, single-molecule plasmon-enhanced Raman spectroscopy (SM-PERS) has developed into a powerful technique for ultrasensitive trace analysis through fingerprint vibrational chemical information. The nanocavity between the coupled plasmonic nanostructures, offering an exceptionally high Raman signal enhancement factor (i.e., plasmonic field hotspot), is crucial for the achievement of SM-PERS. Herein, we first briefly review the development of SM-PERS, followed by an introduction of the features and methodologies of SM-PERS, as well as the applications of SM-PERS in biological analysis, high-resolution chemical imaging, and the investigations of single-molecule reactions. Finally, a perspective highlighting the advancement of new methods and applications of nano-driven SM-PERS is presented.