Open AccessElectrochemical Behavior and Sensitive Determination of l-Tyrosine with a Gold Nanoparticles Modified Glassy Carbon Electrode
Author(s) -
Hao Cheng,
Chen Chang-dong,
Shuai Zhang
Publication year - 2009
Publication title -
analytical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 73
eISSN - 1348-2246
pISSN - 0910-6340
DOI - 10.2116/analsci.25.1221
Subject(s) - chemistry , cyclic voltammetry , glassy carbon , differential pulse voltammetry , electrochemistry , electrode , inorganic chemistry , analytical chemistry (journal) , nuclear chemistry , organic chemistry
The electrocatalytic oxidation of L-tyrosine was investigated on a gold nanoparticles self-assembled glassy carbon electrode (gold nanoparticles/cysteamine/glassy carbon) using cyclic voltammetry and differential pulse voltammetry. Cyclic voltammetry was carried out to study the electrochemical oxidation mechanism of L-tyrosine, which showed an irreversible oxidation process at a potential of 0.681 V at a modified electrode and 0.807 V at a bare glassy carbon electrode. The anodic peak current linearly increased with the square root of the scan rate, suggesting that the oxidation of L-tyrosine at this kind of modified electrode is a diffusion-controlled process. A good linear relationship between the oxidation peak current and the L-tyrosine concentration in the range of 1.0 x 10(-7) to 3.0 x 10(-4) mol L(-1) was obtained in a phosphate buffer solution at pH 7.0. Good sensitivity, selectivity and stability of the modified electrode make it very suitable for L-tyrosine determination in a commercial amino acid oral solution.