Electrochemical behavior and sensitive determination of L-tyrosine with a gold nanoparticles modified glassy carbon electrode.
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.
Cheng
Hao
H
Department of Biological and Chemical Engineering, Guangxi University of Technology, Liuzhou 545006, P. R. China. haochenggxut@gmail.com
Chen
Changdong
C
Zhang
Shuai
S
D000284:Administration, Oral; D016477:Artifacts; D002244:Carbon / Q000737:chemistry*; D003543:Cysteamine / Q000737:chemistry; D004553:Electric Conductivity; D004563:Electrochemistry; D004566:Electrodes; D005898:Glass / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D016014:Linear Models; D053768:Metal Nanoparticles / Q000737:chemistry*; D014443:Tyrosine / Q000008:administration & dosage / Q000032:analysis* / Q000737:chemistry*
D014443:Tyrosine; D003543:Cysteamine; D002244:Carbon; D006046:Gold