TY - JOUR
T1 - Enhancement in the Raman scattering of polypyrrole electrodeposited on roughened gold substrates coated with gold monolayers
AU - Liu, Yu Chuan
PY - 2004/3/4
Y1 - 2004/3/4
N2 - In this study, polypyrrole (PPy) films were electrodeposited on gold substrates roughened by a triangular-wave oxidation-reduction cycle (ORC) in an aqueous solution containing 0.1 N HCl. Extending the applications of self-assembled monolayers, gold monolayers were then adsorbed onto PPy films by dipping the PPy-deposited gold substrates into Au complex-containing solutions, which were produced from the ORC procedure used in roughening the gold substrates. Encouragingly, the surface-enhanced Raman scattering (SERS) spectroscopy of PPy with this sandwiched structure, Au monolayers/PPy/roughened Au substrate, exhibits a higher intensity by 1 order of magnitude and a better resolution, as compared with the normal SERS of PPy electrodeposited on a roughened Au substrate. The enhanced SERS effects can be explained as the electromagnetic effect that correlates to both the Au monolayers above and the roughened Au substrate underneath. Moreover, the chemical effect, which is also contributive to the enhanced SERS effects, is first found from the phenomenon of charge transfer from the pyrrolylium nitrogen to the adsorbed Au-containing complex.
AB - In this study, polypyrrole (PPy) films were electrodeposited on gold substrates roughened by a triangular-wave oxidation-reduction cycle (ORC) in an aqueous solution containing 0.1 N HCl. Extending the applications of self-assembled monolayers, gold monolayers were then adsorbed onto PPy films by dipping the PPy-deposited gold substrates into Au complex-containing solutions, which were produced from the ORC procedure used in roughening the gold substrates. Encouragingly, the surface-enhanced Raman scattering (SERS) spectroscopy of PPy with this sandwiched structure, Au monolayers/PPy/roughened Au substrate, exhibits a higher intensity by 1 order of magnitude and a better resolution, as compared with the normal SERS of PPy electrodeposited on a roughened Au substrate. The enhanced SERS effects can be explained as the electromagnetic effect that correlates to both the Au monolayers above and the roughened Au substrate underneath. Moreover, the chemical effect, which is also contributive to the enhanced SERS effects, is first found from the phenomenon of charge transfer from the pyrrolylium nitrogen to the adsorbed Au-containing complex.
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U2 - 10.1021/jp036915s
DO - 10.1021/jp036915s
M3 - Article
AN - SCOPUS:1542440234
SN - 1520-6106
VL - 108
SP - 2948
EP - 2952
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 9
ER -