Low concentration rhodamine 6G observed by surface-enhanced Raman scattering on optimally electrochemically roughened silver substrates

Abstract

In this work, the effects of preparation conditions in roughening silver substrates by electrochemical triangular-wave oxidation-reduction cycles (ORC) on surface-enhanced Raman scattering (SERS) were investigated. Based on this prepared substrate, the practical limit of detection (LOD) of rhodamine 6G (R6G) can be reduced by six orders of magnitude from 2 × 10⁻⁹ to 2 × 10⁻¹⁵ M, as compared with that of R6G adsorbed on a general procedure-prepared roughened Ag substrate. Further investigations indicate that the content and the oxidation state of Cl on the roughened Ag substrate demonstrate decided effects on the observed SERS.