Trace Analysis of Biological Compounds by Surface Enhanced Raman Scattering (SERS) Spectroscopy

Abstract

Surface enhanced Raman scattering (SERS) spectroscopy is a sensitive analytical technique, which extends its applications to the detection of substances at low concentration levels. SERS spectroscopy measurements were performed on adenine and rhodamine 6G on silver and gold colloids to evaluate the linearity at low analyte concentrations and at different time intervals. The maximum intensity for adenine was observed at Raman shifts of 728 cm-1 and 1318 cm-1 and the maximum intensity for R6G was observed at Raman shifts of 1352 cm-1 and 1519 cm-1. These SERS measurements were compared with solution absorbance measurements at 650 nm and 900 nm. Raman enhancement factors have also been evaluated for each compound. The results of these studies demonstrate that SERS techniques provide high sensitivity and have the potential to detect a range of compounds in biological samples.