Probing the interactions of guanine on silver nanoparticles by surface-enhanced Raman spectroscopy on an electrochemical system

Abstract

Abstract As a typical deoxyribonucleic acid (DNA) base with diverse amino/imino groups, guanine has remarkable Raman activity; however, its Raman modes are largely forbidden in solid Raman measurements, which hinders full understanding of the chemistry of such DNA bases. Here a study on surface-enhanced Raman scattering (SERS) of guanine is reported by employing colloidal silver nanoparticles modified on the silver electrode as substrate. High-quality SERS spectra with potential dependence were obtained, shedding light on the varying adsorption behavior of guanine on the nano-surface. High-quality SERS spectra have also been obtained for picolinic acid molecules. The good stability and homogeneous size distribution of silver nanoparticle coatings provide a highly SERS-active substrate for detecting DNA-bases and probing their local interactions.