From Fundamental toward Applied SERS: Shared Principles and Divergent Approaches

Abstract Over more than 40 years since its discovery, surface‐enhanced Raman scattering/spectroscopy (SERS) has attracted substantial attention as a tool for fundamental research in surface science and for potential analytical sensing applications. This review aims to concisely summarize the essential principles of both the physical and chemical processes underlying Raman signal enhancement, as well as elements of the broader field of plasmonics that are most relevant to SERS. In order to make sense of the overwhelming variety of SERS platforms that are reported, the fabrication, properties, and operational principles of enhancing substrates are given particular attention here in the context of specific application requirements. While the high spatial precision of lithographic techniques has helped to improve the understanding of plasmonic platforms, their prohibitive cost has encouraged the exploration of more facile fabrication methods for more widespread adoption of SERS. Selected examples are introduced to illustrate common themes that recur in fundamental studies, analytical applications, and efforts to produce stable, affordable, and robust SERS sensing platforms.