Resumo

ASADPOUR-ZEYNALI, Karim  e  ALESHI, Mozhdeh. Electrochemical Modification of Glassy Carbon Electrode by Bismuth-chitosan Nanosheets for Electrocatalytic Reduction and Determination of Tartrazine. Port. Electrochim. Acta [online]. 2014, vol.32, n.6, pp.369-379. ISSN 0872-1904.  https://doi.org/10.4152/pea.201406369.

In this paper, a glassy carbon electrode is modified by Bismuth-Chitosan (Bi-Chit) nanosheets. Bismuth, that is “environmentally friendlier'' than mercury, is deposited on a glassy carbon electrode by electrolysis at -0.75 V vs. SCE in a stirring solution containing 0.18 mg mL^-1 Bi(NO₃)₃, 0.05 mg mL^-1 KBr and acetate buffer 0.1 M (pH=4.5) for 200 s. Furthermore, the electrode is modified by chitosan by the means of sonication of bismuth-modified glassy carbon electrode in chitosan solution for 15 minutes. Study of the field emission by scanning electron microscopy (SEM) shows the formation of Bi-Chit nanosheets on the glassy carbon electrode. The modified electrode surface is also characterized by energy dispersive X-ray analysis (EDX). In this research the Bi-Chit modified glassy carbon electrode exhibits excellent catalytic activity toward the electro-reduction of Tartrazine. The modified electrode is successfully used for determination and measurement of Tartrazine in Bisacodyle tablets and chocolates with colorful coatings.

Palavras-chave : Bismuth-Chitosan; Nanosheet; Electrochemical modification; Tartrazine.

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