Uracil Grafted Carbon Electrode:Electrocatalytic Behavior of Tryptophan, Tyrosine, Catecholamine and Related Compounds

Abstract

A uracil grafted glassy carbon electrode (Ura/GCE) was fabricated and characterized by X-ray photoelectron spectroscopy (XPS), cyclic voltammertry (CV) and differential pulse voltammetry (DPV) techniques. The electrochemical behavior of tryptophan (Trp), tyrosine (Tyr), catecholamine such as dopamine (DA), epinephrine (EP) and norepinephrine (NE), and related compounds involving uric acid (UA) and ascorbic acid (AA) at the Ura/GCE was investigated. All these bioactive species could be electrocatalytically oxidized to generate very different current sensitivities. This electrode can be used as a versatile electrochemical sensor for DA, EP, NE, UA, Trp and Tyr determination. The DPV peak potential, current sensitivity, linear range and detection limit of these species were obtained and used for analysis of molecular interactions between uracil and those electroactive species. A mechanism for the surface accumulation was discussed.

Antioxidant and Electron Donating Function of Hypothalamic Polypeptides: Galarmin and Gx-NH2

“…manifesting itself as an antioxidant-chelator, the Galarmin simultaneously maintains its antiradical activity and reduction properties. Earlier, by the voltammetry method the molecules of tyrosine, tryptophan, cystein and their residues in the polypeptides were identified as well [21][22][23][24].…”

Simultaneous determination of tryptophan and tyrosine in binary mixture by zero-crossing second derivative spectrophotometry.

“…A survey of the literature revealed that the analysis of tryptophan and tyrosine either in single or multicomponent mixtures has been reported through high performance liquid chromatography [3][4][5][6], voltammetry [7], gas chromatography [8], liquid chromatography [9], thin-layer chromatography [10,11], electrochemical [12,13] and differentialderivative [14][15][16][17] methods.…”