Surface‐Enhanced Raman Spectroscopy: General Introduction

Abstract The surface‐enhanced Raman scattering effect refers to the effect was discovered in the mid‐1970s, by which the intrinsically low detection sensitivity of Raman spectroscopy is no longer a fatal disadvantage for this analytical tool. As a general introduction of surface‐enhanced Raman spectroscopy (SERS), the over 40‐year history of SERS is first overviewed, showing that SERS has gone through a tortuous pathway to develop into a powerful diagnostic technique. We then describe the principle of SERS and enhancement mechanisms, illustrating that SERS is mainly surface plasmon resonance (SPR) and nanostructure‐enhancement phenomenon. The SERS measurement procedures, in particular the preparation of various SERS active substrates, are discussed. Based on the four important criteria in analytical science, i.e. detection sensitivity (energetic, spatial, and temporal), resolution, generality, and reliability, we highlight two different approaches to utilize the strength and offset the weakness of SERS. With the enormously high sensitivity and spectral resolution, SERS has been applied successfully to surface analysis and trace analysis by gaining meaningful information from an extremely small quantity of species even down to single molecules. To significantly improve the surface generality and spatial resolution, tip‐enhanced Raman spectroscopy (TERS) was invented in 2000. To greatly improve the material generality and measurement reliability, shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) was introduced in 2010. Finally, prospective developments of SERS in substrates, methods, and theory are briefly discussed.