Distinct Adsorbed States of DNA and RNA Bases Investigated by Flocculation-Assisted Surface Enhanced Raman Scattering

Abstract

We have succeeded in forming flocculates of gold nanoparticles (AuNPs) using DNA and RNA bases to obtain their surface enhanced Raman spectra. Adenine, guanine and cytosine molecules which possess a primary amino group (-NH₂) formed flocculates at much lower concentration than uracil and thymine without an -NH₂ group, suggesting a crucial role of an -NH₂ group for adsorption of these base molecules on neighboring AuNPs. Detailed adsorption structure of base molecules was investigated using their SERS spectra at various pH in solutions and those for deuterated bases, comparing with those for bulk state and also by DFT calculations. [DOI: 10.1380/ejssnt.2015.223]