A Conceptual Overview of Surface-Enhanced Raman Scattering (SERS)

This review briefly delves into the fundamental considerations of surface-enhanced Raman scattering (SERS). This technique combines Raman spectroscopy and nanotechnology with great potential for molecular fingerprint identification. SERS has been associated with remarkable characteristics: high-resolution detection for a small amount of sample, high sensitivity of Raman measurement, and more fluorescence quenching. The amplification of Raman signals can be enhanced by two different mechanisms: electromagnetic enhancement and charge transfer. The electromagnetic mechanism depends on localized surface plasmon resonance phenomena and the generation of hotspots. The charge transfer mechanism involves the electron transfer between the metal substrate and the molecule of interest. The sensing approach of SERS could be a label-free or label-based approach adsorbed on the substrate surface. The main challenge of the reproducibility of SERS substrates can be mitigated by development in nanotechnology. Surface-enhanced resonance Raman spectroscopy (SERRS), shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS), and tip-enhanced Raman spectroscopy (TERS) are other methods for generating enhancement of the Raman signal.