Surface enhanced Raman scattering (SERS) - a quantitative analytical tool?

Raman spectroscopy is a widely used analytical tool capable of providing valuable information about the chemical structure and composition of molecules. In order to detect substances also at a very low concentration levels, Surface Enhanced Raman Scattering (SERS) was introduced. The different amplification mechanisms result in extreme sensitivity, however, a quantitative use of SERS appears to be problematic. Especially, when deploying silver sols as SERS substrates, the reproducibility of the signal intensities for a given substance concentration is questionable. Experimental results of an investigation of this problem for low concentrations of adenine are presented. Comparison with results obtained for different SERS substrates by other authors reveals clearly different dependencies. Only in a very limited concentration range reproducible and therefore quantitatively utilizable data could be obtained. Copyright (C) 2006 John Wiley & Sons, Ltd.