摘要
本文以强烈吸附在石墨电极上的亚甲绿作为电子传递媒介体构成修饰电极.在-0.25V～+0.10V电位区间内,吸附态的亚甲绿表现出相当可逆的氧化还原行为,电极反应有一个电子和一个质子参加.在pH=7.0的磷酸盐缓冲溶液中,其式量电位 E °’ 为-0.14V,表观电子传递速率常数K_(app)为4.4s^(-1).亚甲绿修饰电极对还原型烟酰胺腺嘌呤二核苷酸(NADH)的电化学氧化具有明显的催化作用,可使NADH的氧化过电位降低500mV,它作为NADH的电化学安培检测器具有很高的灵敏度和良好的重现性.文中还用X光电子能谱(ESCA)、衰减全反射红外光谱(ATR)等现代分析技术对修饰电极进行了表征.
The chemically modified electrode(CME), which was constructed by adsorbing the mediator methylene green(MG) onto the spectrographic graphite electrode, shows significant electrocatalytic activity to the oxidation of reduced nicotinamide adeninedinucleotide (NADH), reducing oxidation overpotential by 500mV. In the potential range from -0.25 V to +0.1V the adsorbed mediator MG behaves as one-electron reversible redox process involving one proton. In the medium of 0.1mol/dm3 phosphate buffer (pH=7.0) the surface formal potential E°' and apparent electron-transfer rate of the adsorbed mediator MG were found to be -0.14V and 4.4s-1, respectively. The CME was tested as a electrochemical NADH detector, which shows high sensitivity and good stability. The CME was also characterized by ESCA and ATR.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1995年第4期362-368,共7页
Acta Chimica Sinica
基金
国家自然科学基金
国家教委博士点基金资助项目.
