The SERS effect
What is the SERS effect?
The SERS effect is the term used to describe the phenomenon of the enhancement of the Raman signal. There is still a lot of discussion about the underlying mechanism of this specific enhancement in literature. Throughout literature two main mechanisms of how SERS works are described, which are both accepted. The SERS effect can be explained by the electromagnetic (based on excitation of the localized surface plasmons) and the chemical (based on charge transfer complex formation of the analyte) model (2). The enhancement factor (EF) is a number that is widely used to characterize the SERS effect, which is a measure of how much the Raman signal is amplified. Different factors can be taken into account to calculate the final EF and therefore this number could be meaningless when comparing between different SERS substrates.
2) Ujjal Kumar Sur: Surface-enhanced Raman scattering (SERS) spectroscopy: a versatile spectroscopic and analytical technique used in nanoscience and nanotechnology. Advances in Nano Research 2013