Improved surface-enhanced Raman scattering on electrochemically roughened silver substrates prepared in bielectrolyte solutions.

Yu-Chuan Liu, Cheng-Cai Wang, Jeng-Feng Tsai

Index: Anal. Chim. Acta 584(2) , 433-8, (2007)

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Abstract

In this work, the effect of supplemental LiClO(4) electrolytes in KCl solutions used in roughening silver substrates by electrochemical triangular-wave oxidation-reduction cycles (ORC) on surface-enhanced Raman scattering (SERS) was first investigated. To prepare SERS-active substrates by ORC procedures, electrolytes of KCl were generally employed. In contrast, LiClO(4) ones were unsuitable for producing SERS-active substrates. Encouragingly, SERS of Rhodamine 6G (R6G) adsorbed on the roughened Ag substrate prepared in an aqueous solution containing KCl and LiClO(4) electrolytes exhibits a higher intensity by one order of magnitude, as compared with that of R6G adsorbed on a roughened Ag substrate prepared in a solution only containing KCl. Further investigations indicate that the oxidation state of Cl on the roughened Ag substrate demonstrates decided effects on this improved SERS.