Surface-enhanced Raman spectroscopy

Surface-enhanced Raman spectroscopy (SERS) is a spectroscopic technique that simultaneously combines fingerprint recognition capabilities, typical of vibrational spectroscopies, and very high sensitivity (down to single molecule), owing to the enhancement provided by plasmonic effects. SERS inherits the rich chemical fingerprint information on Raman spectroscopy and gains sensitivity by Plasmon-enhanced excitation and scattering. In particular, most Raman peaks have a narrow width suitable for multiplex analysis, and the measurements can be conveniently made under ambient and aqueous conditions. SERS applications in bio analysis involve the complex interactions of plasmonicnanomaterials with biological systems and their environments. We then introduce the current understanding of the interaction of nanomaterials with biological systems, mainly living cells, to guide the design of functionalized SERS nanoparticles for target detection. In the end, we give an outlook of the key challenges in bio analytical SERS, including reproducibility, sensitivity, spatial and time resolution.  The last section illustrates the applications of SERS in several fields of sensing, like the detection of chemical warfare agents, environmental pollutants, food contaminants, and illicit drugs; the use of SERS in art preservation, forensic science, and medical diagnosis. Keywords: SERS, Plasmon’s, Enhancement, Nanoparticles, Resonance, Finger printing