酶电极上葡萄糖氧化酶的活性的X射线微区分析

利用X射线微区分析,对二氧化硅溶胶-凝胶包埋于普鲁士蓝修饰玻碳电极上的葡萄糖氧化酶的活性进行了分析;以Ce(NO3)3为捕捉剂,底物葡萄糖经葡萄糖氧化酶作用产生过氧化氢,后者与捕捉剂反应生成沉淀于酶的活性部位。从X射线微区分析结果表明:酶电极表面固定化酶的分布均匀,且保存较高的酶活,从微观的角度说明了酶电极的性能与酶电极表面酶活分布的关系。此法制备的葡萄糖氧化酶电极具有较高的灵敏度,稳定性,这与电化学测试结果是一致的。

X-Ray Microanalysis of the Activity of Immobilized Glucose Oxidase on Enzyme Electrode

The localization of activity of glucose oxidase (GOD) on the pussian blue modified electrode by SiO_2 sol-gel was studied by X-ray microanalysis. Glucose and Ce(NO_3)_3 served as substrate and capture respectively. Substrate was catalysed by immobilized GOD to produce H_2O_2, and the H_2O_2 was captured by Ce(NO_3)_3 to form precipitate. The precipitation deposited the active site of (immobilized) GOD on the enzyme electrode. The X-ray microanalysis showed that the distribution of active enzyme on the surface of the enzyme electrode was uniform, and the GOD immobilized maintained high activity. The X-ray analysis exhibited that the properties of the enzyme electrode depended on the distribution of enzyme activity on its surface from the view of microstructure, and the developed GOD electrode was of high sensitivity and excellent stability. The results agreed with the results of the electrochemical study.