Surface Enhanced Raman Scattering:
Surface Enhanced Raman Scattering (SERS) was discovered in the year of 1974 when it was found which pyridine molecules adsorbed on an electrochemically roughened surface gave intense Raman Signals; much larger than the generally expected. This technique additionally developed in 1970s and includes taking spectra of the samples adsorbed on the surfaces of colloidal metal particles such as gold or silver. The Raman scattering from a compound (or ion) adsorbed on such a metal surface could be 103-106 times greater than in solution.
The surface-enhanced Raman scattering is found to be strongest on silver, but is observable on copper and gold as well. By the exact mechanism of the effect is not known but it is believed in which SERS is a combination of chemical enhancement of polarisability through the bonds formed among the sample and the surface, and the electromagnetic resonance of little gold or silver particles. SERS combined along with RRS could give a large increase in the sensitivity and the detection limits might go down to nano or even picomolar range.
SERS searches applications within diverse areas. For instance, in forensic sciences it could be used to examine the microstructure of forged handwriting through analysing whether the type (or types) of the ink used are different. SERS is also significant in life sciences as it can be used for biological materials within their physiological media.
There are several more ways of improving the quality of the Raman spectra but these are beyond the scope of present context.