Determination of alpha-Lipoic acid on a Pyrolytic Graphite Electrode Modified with Cobalt Phthalocyanine

Author(s)

Ferreira, Ana Paula M. ^[1] ; dos Santos Pereira, Laise N. ^[1] ; da Silva, Iranaldo Santos ^{[1, 2]} ; Tanaka, Sonia M. C. N. ^[1] ; Tanaka, Auro A. ^{[1, 3]} ; Angnes, Lucio ^[2]

Affiliation

^[1] Univ Fed Maranhao, Dept Quim, BR-65080805 Sao Luis, MA - Brazil

^[2] Univ Sao Paulo, Inst Quim, BR-05508000 Sao Paulo, SP - Brazil

^[3] Inst Nacl Ciencia Tecnol Bioanalit, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: Electroanalysis; v. 26, n. 10, p. 2138-2144, OCT 2014.
• Web of Science Citations: 6

Abstract

In this work voltammetric techniques were explored for quantification of a-Lipoic acid (ALA) using a pyrolytic graphite electrode modified with cobalt phthalocyanine. Cyclic voltammograms recorded in phosphate buffer solution containing 1 x 10(-3) mol L-1 of ALA presented an oxidation peak located at +0.8 V vs. SCE. The modification of the electrode produced a 100 mV shift of the onset oxidation potential to less positive value and a substantial increase in the ALA oxidation current. Among the voltammetric techniques explored, differential pulse voltammetry showed the best performance for quantifications of the analyte in low concentrations. Limits of detection and quantification of ALA obtained corresponds to 3.4 x 10(-9) mol L-1 and 1.2 x 10(-8) mol L-1, respectively. (AU)

• FAPESP's process: 13/16960-3 - Voltammetric sensors containing mesoporous Silica modified with gold nanoparticles and nitroheterocyclic compounds with antichagasic activity - Bioelectrochemical Applications.
• Grantee: Iranaldo Santos da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctorate