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International Journal of Analytical Chemistry
Volume 2012 (2012), Article ID 923208, 10 pages
http://dx.doi.org/10.1155/2012/923208
Research Article

Multilayer Films Electrodes Consisted of Cashew Gum and Polyaniline Assembled by the Layer-by-Layer Technique: Electrochemical Characterization and Its Use for Dopamine Determination

1Departamento de Química, Centro de Ciências da Natureza (CCN), Universidade Federal do Piauí (UFPI), 64049550 Teresina, PI, Brazil
2DB, Universidade Federal do Piauí (UFPI), Campus Senador Helvídio Nunes de Barros (CSHNB), 64600000 Picos, PI, Brazil
3SEDIS, Universidade Federal do Rio Grande do Norte (UFRN), Caixa Postal 1524, Campus Universitário Lagoa Nova, 59072970 Natal, RN, Brazil
4Nanomedicine and Nanotoxicology Laboratory, IFSC, University of São Paulo, São Carlos, SP, Brazil
5Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, Campus Ministro Reis Velloso, CMRV, Universidade Federal do Piauí, UFPI, 64202020 Parnaíba, PI, Brazil

Received 1 October 2011; Revised 10 December 2011; Accepted 3 January 2012

Academic Editor: Ricardo Vessecchi

Copyright © 2012 Sergio Bitencourt Araújo Barros et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We take advantage of polyelectrolyte feature exhibited by natural cashew gum (Anacardium occidentale L.) (CG), found in northeast Brazil, to employ it in the formation of electroactive nanocomposites prepared by layer-by-layer (LbL) technique. We used polyaniline unmodified (PANI) or modified with phosphonic acid (PA), PANI-PA as cationic polyelectrolyte. On the other hand, the CG or polyvinyl sulfonic (PVS) acids were used as anionic polyelectrolytes. The films were prepared with PANI or PANI-PA intercalated with CG or with PVS alternately resulting in four films with different sequences: PANI/CG PANI-PA/CG, PANI/PVS and PANI-PA/PVS, respectively. Analysis by cyclic voltammetry (CV) of the films showed that the presence of gum increases the stability of the films in acidic medium. The performance of the modified electrode of PANI-PA/CG was evaluated in electro analytical determination of dopamine (DA). The tests showed great sensitivity of the film for this analyte that was detected at 10−5 mol L−1.