Poly(2-bis-aminophenyldisulfide) and Polythiothene / Platinum-Particles Modified Electrodes. Prospective Applications in Sensing and Electrocatalysis

• Published in: International journal of electrochemical science 2011-12, Vol.6 (12), p.6105-6114
• Main Authors: Valle, M. A. del, Santander, R.A., Díaz, F.R., Faúndez, M., Gacitúa, M., Antilén, M., Hernández, L.A.
• Format: Article
• Language: English
• Subjects: electropolymerization; modified electrodes; platinum particles; poly(2-bis-aminophenyldisulfide); polythiophene
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/S1452-3981(23)19666-0

In this paper electrode miniaturization with prospective use in electro-catalysis or as sensors is proposed. To this purpose it was postulated that dispersion of metal particles in a polymer matrix increases the effective area, on the same geometric area. In addition, the catalytic effect would significantly improve the sensitivity and detection limit toward the analyte compared to the same electrode material when used in massive form. In this first study, besides of verifying the catalytic properties towards formic acid oxidation, the determination of nifedipine in its OROS (Osmotic Release Oral System) formulation is proposed to test the hypothesis and to lay the groundwork for more concrete proposals regarding this matter. Platinum proved to be the most suitable for nifedipine oxidation, therefore this metal was selected to be dispersed in the polymer matrix. In the current survey 2-bis-(aminophenyldisulfide), APDS, and thiophene, Th, electro-deposited on gold and platinum electrodes respectively. After, platinum dispersion was carried out by applying reduction potentials at the polymer modified electrodes on a hexachloroplatinic acid solution. These composite electrode were then used for HCOOH electro-oxidation. The results also demonstrated, firstly, that the catalytic effect on formic acid is higher when platinum was dispersed into poly-APDS and, secondly, that indeed the used methodology would allow the polymer to increase the metal effective area and thus, the sensitivity for analyte determination. However, the morphology of the polymeric matrix should be optimized as a function of the analyte size before optimizing its use as sensor.