TOLUIDINE BLUE COVALENTLY IMMOBILIZED ONTO GOLD ELECTRODE SURFACES - AN ELECTROCATALYTIC SYSTEM FOR NADH OXIDATION
TOLUIDINE BLUE COVALENTLY IMMOBILIZED ONTO GOLD ELECTRODE SURFACES - AN ELECTROCATALYTIC SYSTEM FOR NADH OXIDATION
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DOI：
10.1002/elan.1140060903
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发表时间：
1994-09-01
期刊：
影响因子：
3
通讯作者：
SCHMIDT, HL
中科院分区：
文献类型：
--
作者：
SCHLERETH, DD;KATZ, E;SCHMIDT, HL
研究了甲苯胺蓝在溶液中的电化学行为，发现电极表面性质对甲苯胺蓝的电化学行为有很强的依赖性。胱胺（C）或3-巯基丙酸（MP）化学吸附在金电极表面上的单层膜已被用作甲苯胺蓝（TOB）通过其3位的芳族氨基和覆盖电极表面的氨基或羧基共价连接的载体。TOB共价连接到MP单分子膜上后，有三种不同的物质稳定地连接在电极表面：物理吸附的TOB，其中点电位与增溶状态相同，E（1/2）= -245 mV（Ag/AgCl）;甲苯胺蓝修饰电极在-100 mV处开始催化氧化NADH，其电流响应依赖于底物浓度。在连续加入NADH后观察到电极结垢过程，导致催化活性损失。
The electrochemical behavior of toluidine blue in solution has been studied and found to be strongly dependent an the electrode surface nature. Monolayers of cystamine (C) or 3-mercaptopropionic acid (MP) chemisorbed onto gold electrode surfaces have been used as support for covalent attachment of toluidine blue (TOB) through its aromatic amino group in position 3 and the amino or carboxylic groups covering the electrode surface. After covalent attachment of TOB onto an MP monolayer, three different species remained stably attached to the electrode surface, Physically adsorbed TOB, which showed the same midpoint potential as in the solubilized state, E(1/2) = -245 mV (Ag/AgCl); covalently attached TOB, whose midpoint potential was shifted toward 120 mV more positive potentials; and an unknown species, probably physically adsorbed TOB dimers, with a midpoint potential, E(1/2) = +135 mv (Ag/AgCl).Toluidine blue modified electrodes started to oxidize catalytically NADH at -100 mV with an amperometric response dependent on the concentration of the substrate. An electrode fouling process was observed after successive additions of NADH leading to the loss of catalytic activity.