Effect of preparation conditions for roughening gold substrate by oxidation-reduction cycle on the surface-enhanced Raman spectroscopy of polypyrrole

The surface-enhanced Raman spectroscopy (SERS) of polypyrrole (PPy) can be obtained by roughening the An substrate with electrochemical oxidation-reduction cycle (ORC) before PPy deposition. The optimum condition for obtaining SERS effect is based on the strongest peak of C=C backbone stretching of PPy located at ca. 1600 cm(-1) shown in SERS. The optimum preparation conditions are as follows. Cathodic and anodic vertex potentials are -300 and 1200 mV vs. SCE. respectively. Delays at cathodic and anodic vertex potentials are 10 and 2 s, respectively. Cathodic and anodic scan rates are 500 and 1000 mV s(-1), respectively. The ORC cycle is 25 times. Also, the result indicates that the SERS effect decreases with increasing the charge passed for PPy deposition. (C) 2002 Elsevier Science B.V. All rights reserved.