Electrocatalytic oxidation of L-tyrosine by a nitroxide.
The electrochemistry of L-tyrosine was studied by cyclic voltammetry at a glassy carbon electrode. Although L-tyrosine itself showed very poor electrochemical response, the response could be greatly enhanced by using 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxy (HO-TEMPO) as a mediator that enables a sensitive determination of the substrate. An electrocatalytic EC' mechanism with the oxoammonium ion of HO-TEMPO as the active oxidant is proposed. The catalytic rate constant was determined to be 2.0 x 10(4) M(-1) s(-1) by using chronoamperometry.
Wen
X L
XL
Department of Physics, National Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, People's Republic of China.
Jia
Y
Y
Yang
L
L
Liu
Z L
ZL