SURFACE ENHANCED RAMAN SPECTROSCOPY (SERS): A TOOL FOR MODERN BIOANALYSIS AND FORENSIC ANALYSIS

Raman spectroscopy is a strong, non-destructive vibrational method of allow elemental examination that can provide much specific molecular fingerprinting evidence, but its practical limit of detectability is limited by the inherently weak Raman scattering section. Surface-Enhanced Raman Spectroscopy (SERS) addresses this limitation through exploiting plasmonic nanostructures made of noble metals thus amplifying Raman signals by multiple orders of magnitude and allowing trace-level (even single-molecule) sensitive detection. The chapter has a detailed and methodical account of the basics behind Raman scattering, including the Rayleigh, Stokes, and anti-Stokes scattering, and their classical theory explanations. The physical principles of SERS improvement such as electromagnetic hotspots created by localized surface plasmon resonances and chemical effects enhancement are discussed in detail. The aspects of instrumentation, e.g., laser excitation, optical filters, spectral dispersion, and detector technologies, are analysed thoroughly after which the description of the typical SERS experiment setups is given in details. Lastly, the chapter clarifies the analytical benefits of SERS over traditional spectroscopic and chromatographic methods, as well as defines its emerging use in bioanalysis, forensics, environmental monitoring and chemical sensing. This standardized treatment is aimed at providing a reference base to the researchers and practitioners using SERS in higher order of analysis.