Surface-enhanced Raman spectroscopy (SERS) is a variation of Raman spectroscopy whereby the molecule of interest is first adsorbed onto a surface, often of silver or gold, rather than being studied in solution. The defining advantage of this approach is that the observed intensity of the spectrum is much greater than in solution studies. This effect is strongly associated with the use of nanoscale surfaces for adsorption.
It is clear from reading the article ‘Persistent misconceptions regarding SERS’ by Martin Moskovits, that explaining the mechanism of the phenomenon underlying this technique is still the matter of an intense and interesting debate. It is very possible that this lack of consensus contributes to the fact that SERS is yet to be successfully explained by quantum mechanics, and the theory used to explain it is still classical in nature.
In his article, Moskovits makes it clear that his favoured candidate to explain the enhancement mechanism is the plasmonic theory, which he explains clearly and succinctly. He then systematically examines the other popular theories, and provides arguments that in his view display the superiority of the plasmonic mechanism. He writes particularly strongly against the chemical enhancement theory, and urges its abandonment. Moskovits further suggests that the disagreements amongst SERS researchers may have resulted in opportunities to use the technique being missed due to uncertainty over its mechanism.
As research techniques undergo simultaneous development by multiple research groups, it is unsurprising that differences of opinion and opposing theories arise. If a particular view becomes popular, it can become so widely accepted that it is taken as fact and remains unchallenged for many years. It is therefore important that opposing views are presented, as in this article, in order that the relevant research community may consider their merits.
by Victoria Wilton
Form your own opinion – read the Perspective today:
Persistent misconceptions regarding SERS
Martin Moskovits
DOI: 10.1039/C2CP44030J
