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Updated: Jun 24, 2026
Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds
Published on: October 12, 2018
Surface-enhanced resonance Raman scattering of polyaniline on silver and gold colloids
Celly M S Izumi1, Gustavo F S Andrade, Marcia L A Temperini
1Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, CP 26.077, CEP 05513-970, São Paulo, SP, Brazil.
Abstract:
The interaction of emeraldine base (PANI-EB) with silver and gold colloids was probed by using Surface-Enhanced Resonance Raman Scattering (SERRS) at 3 different exciting radiations. Due to the great sensitivity of SERRS technique the detection limit of PANI-EB concentration was ca. 2 x 10(-7) mol L(-1) in Ag and Au colloidal suspensions. The UV-vis-NIR spectra of metal colloids in function of PANI-EB concentrations showed that gold colloids present a higher degree of aggregation than silver colloids. SERRS of PANI-EB on metal colloids allowed the study of the polymeric species formed primarily on the metallic surface. The polymer formed after the adsorption of PANI-EB on metallic nanoparticles is strongly dependent on the nature of the metal colloids. The oxidation of PANI-EB to pernigraniline occurred for silver colloids, while a doping process of PANI-EB on Au nanoparticles was evidenced through the observation of the characteristic SERRS spectrum of emeraldine salt at 1064nm.
