Surface-enhanced Raman scattering (SERS) of nucleic acid components in silver sol: Adenine series

Abstract

Surface-enhanced Raman scattering (SERS) of adenine, adenosine, 2′-deoxyadenosine, 5′-dAMP, 5′-rAMP, 5′-rADP and 5′-rATP adsorbed on aqueous Ag sol has been investigated. A shift of the adenine ring breathing mode from 746 to 735 cm−1 with increasing adenine concentration is interpreted as reflecting the reorientation of adenine on the Ag surface. Such a shift is not observed for adenosine, 2′-deoxyadenosine and 5′-dAMP. SERS spectra of 5′-rAMP, 5′-rADP and 5′-rATP can be obtained either at neutral pH in the presence of pyridine or by lowering the pH of the Ag sol. The pH effect is discussed in terms of surface plasmon resonance theory.