Electrochemical Modification of Glassy Carbon Electrode by Bismuth-chitosan Nanosheets for Electrocatalytic Reduction and Determination of Tartrazine

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.