Electrochemical polymerization of sunset yellow on carbon ceramic electrode and electrocatalytic activity for oxidation of tryptophan

The compounds which provide chromophore azo group (-N=N-) form a piece of conjugate system together with two or more aromatic ring in their structure and combination of these rings are called azo dye matrial [1]. Sunset yellow (E-110, sy) is one of the synthetic dyes that contain the azo group as chromophore in its molecular structure, have during several years widely use as food coloring agent in many countries[2-3]. In the present work, sunset yellow as a food dye, has been polymerized on ceramic carbon electrodes using cyclic voltammetry and the formation of polysunset yellow nano films has been confirmed. The characteristics and morphology of polysunset yellow synthesized on carbon cermic electrode were characterized by SEM and FT-IR, NMR and TGA. The electrochemical behavior of polysunset yellow modified carbon ceramic electrode showed a pair of symmetrical redox peaks at a formal redox potential, E`0=-0.03V vs. Ag/AgCl. The carbon ceramic electrode modified with polysunset yellow showed eletrocatalytic activity towards oxidaization of tryptophan. Under optimal experimental conditions, the carbon ceramic electrode modified with polysunset yellow exhibited a EC´ mechanism for the selective electrooxidation of tryptophan in the presence of other amino acids (pH= 5, phosphate buffer solution).