ELECTROCHEMICAL OXIDATION OF L-ASCORBIC-ACID ON 7,7,8,8-TETRACYANOQUINODIMETHANE (TCNQ) MODIFIED ELECTRODE

被引：31

作者：

MURTHY, ASN

ANITA

机构：

[1] Department of chemistry, Indian Institute of Technology, New Delhi

来源：

BIOSENSORS & BIOELECTRONICS | 1994年 / 9卷 / 06期

关键词：

MODIFIED ELECTRODE; TCNQ; ASCORBIC ACID; CYCLIC VOLTAMMETRY; ELECTROCATALYSIS;

D O I：

10.1016/0956-5663(94)90032-9

中图分类号：

Q6 [生物物理学];

学科分类号：

071011 ;

摘要：

A new chemically modified electrode for electrocatalytic oxidation of ascorbic acid is described. 7,7,8,8-Tetracyanoquinodimethane (TCNQ) is immobilised on edge plane pyrolytic graphite by immersing the electrode in a toluene solution of TCNQ for one hour. The surface coverage as determined by cyclic voltammetry, is 6.1 x 10(-9) mol cm-2. The electrocatalytic activity of TCNQ modified electrode for ascorbic acid oxidation in phosphate buffer solutions (pH 7.0) is shown by cyclic voltammetry at a potential of 0.08 V vs. Ag/AgCl. The modified electrode is stable and shows linear variation of current with concentration of ascorbic acid in the range 1-10 mM. The rate constant for the reaction between ascorbic acid and immobilized TCNQ is estimated to be 1.8 x 10(6) M-1 s-1 and is therefore ideally suited for a quantitative determination of ascorbic acid.

引用

页码：439 / 444

页数：6

共 18 条

[1] HETEROGENEOUS (CHEMICALLY MODIFIED ELECTRODES, POLYMER ELECTRODES) VS HOMOGENEOUS CATALYSIS OF ELECTROCHEMICAL REACTIONS [J].