XII Iberian Meeting of Electrochemistry XVI Meeting of the ...
XII Iberian Meeting of Electrochemistry XVI Meeting of the ...
XII Iberian Meeting of Electrochemistry XVI Meeting of the ...
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<strong>XII</strong> <strong>Iberian</strong> <strong>Meeting</strong> <strong>of</strong> <strong>Electrochemistry</strong> & <strong>XVI</strong> <strong>Meeting</strong> <strong>of</strong> <strong>the</strong> Portuguese Electrochemical Society PC 01<br />
A Conducting Polymer / Self-Assembled Monolayer Modified<br />
Electrode for <strong>the</strong> Determination <strong>of</strong> Ascorbic Acid<br />
José Carlos A. Mesquita 1 , Sónia Maria A. Fernandes 1,2 , Jorge M. G. Teixeira 2<br />
1 Centro de Química da Madeira. LQCMM/CQM, Universidade da Madeira,<br />
Campus da Penteada, 9000-390 Funchal<br />
2 Departamento de Química da Universidade de Évora, Colégio Luís Verney, 7000 Évora<br />
jcm@uma.pt<br />
Self-assembled monolayers (SAMs) have become a convenient way <strong>of</strong> surface<br />
modification in order to obtain highly organized structures with well-defined properties,<br />
in particular through <strong>the</strong> incorporation <strong>of</strong> appropriate terminate functional groups [1, 2].<br />
The technique <strong>of</strong> electrostatic self-assembly layer-by-layer proposed by Decher et al in<br />
<strong>the</strong> 90s, which allows obtaining multilayer thin films, also enables <strong>the</strong> self-assembly <strong>of</strong><br />
conducting polymers [1]. However, several authors electropolymerize directly<br />
conducting polymers on SAMs [3] with particularly <strong>the</strong> intention <strong>of</strong> obtaining polymer<br />
layers with increased adherence.<br />
In this work, it is compared <strong>the</strong> voltammetric behaviour <strong>of</strong> <strong>the</strong> polyaniline (PANI)<br />
electrodeposited on 3-mercapto-1-propanesulfonic acid (MPS) self-assembled on a<br />
carbon electrode (C) with that <strong>of</strong> <strong>the</strong> PANI chemically syn<strong>the</strong>sized self-assembled by<br />
electrostatic interaction equally on MPS. Complementarily, <strong>the</strong> cyclic voltammetric<br />
study <strong>of</strong> <strong>the</strong> PANI deposited on MPS self-assembled on carbon provided valuable<br />
information about <strong>the</strong> modified electrodes thus obtained.<br />
Additionally, it is verified by cyclic voltammetry that with <strong>the</strong> C/MPS/PANI modified<br />
electrode it is possible to well define <strong>the</strong> oxidation <strong>of</strong> <strong>the</strong> acid ascorbic (AA), besides not<br />
arise any fur<strong>the</strong>r oxidation <strong>of</strong> this chemical species. Fur<strong>the</strong>rmore, it is observed with<br />
C/MPS/PANI modified electrodes a good correlation <strong>of</strong> <strong>the</strong> acid ascorbic voltammetric<br />
current with <strong>the</strong>ir concentration. What gives a positive perspective for <strong>the</strong> use <strong>of</strong> this<br />
kind <strong>of</strong> modified electrode in <strong>the</strong> determination <strong>of</strong> AA.<br />
Acknowledgments: Sónia Fernandes acknowledges Secretaria Regional da Educação da Madeira<br />
for <strong>the</strong> grant. We gratefully acknowledge <strong>the</strong> NMR Portuguese Networks (REDE/1517/RMN/2005).<br />
The support from F CT (Pluriannual base funding) and CS Madeira is also gratefully<br />
acknowledged.<br />
References<br />
[1] Paterno, L.G.; Mattoso, L.H.C.; Oliveira Jr. O.N. Quim. Nova, 2001, 24, 228.<br />
[2] Love, J.C.; Estr<strong>of</strong>f, L.A.; Kriebel, J.K.; Nuzzo, R.G.; Whitesides G.M. Chem. Rev., 2005, 105,<br />
1103.<br />
[3] Mazur, M.; Krysinski, P.; Jackowska K. Thin Solid Films, 1998, 330, 167.<br />
September, 811, 2010. ISEL - Lisbon 79
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