期刊
ANALYTICAL CHEMISTRY
卷 86, 期 15, 页码 7530-7535出版社
AMER CHEMICAL SOC
DOI: 10.1021/ac501289x
关键词
-
资金
- European Research Council (ERC) in the 7th EU Research Framework Program (FP7)/ ERC [240544]
- state North Rhine Westphalia
The pH dependent redox potential of the oxidoreductase glucose oxidase (GOx) from Aspergillus niger, which is the most frequently applied enzyme in electrochemical glucose biosensors and biofuel cells, was measured between pH 4.5 and 8.5 using UV/vis spectroelectrochemistry. In the entire pH range under investigation, the flavin adenine dinucleotide cofactor of GOx changed directly from the oxidized quinone to the doubly reduced hydroquinone. No stable semiquinoid species could be detected if electrochemical equilibrium was reached. From the pH dependency of the GOx redox potential, a pK(a) of 7.2 has been determined for the GOx flavohydroquinone. At pH values <= 6.0, a dependency of the reduction mechanism and the GOx redox potential on the presence of halides, especially on Cl-, was observed. For the development of glucose biosensors and glucose biofuel cell anodes working at physiological or neutral pH, the GOx redox potentials at pH 7.4 and pH 7.0 are of main interest. Here values of E-1/2 pH 7.4 = -97 +/- 3 mV and E-1/2 pH 7.0 = -80 +/- 4 mV have been determined.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据