葡萄糖氧化酶修饰聚苯胺电极的动力学

The Kinetics of Glucose Oxidase Modified Polyaniline Electrode

虽然固定酶有吸附、交联、共价结合和捕集等多种方法,但寻找其新的固定方法仍是感兴趣的研究课题。利用导电高聚物的导电性和掺杂作用,将酶直接固定在导电高聚物上,这种方法简单,固定后的酶仍保持原有的活性。用聚苯胺固定葡萄糖氧化酶已有报道。但电极的活性有效期较短。考虑到固定酶的性质不仅取决于酶本身的性质,而且还受载体性质和固定方法的影响,我们曾用还原后的聚苯胺在酶溶液中氧化而固定酶,本文在文献的基础上,研究了葡萄糖氧化酶修饰聚苯胺电极的动力学特性、pH效应及其使用稳定性。

The reaction rate-limiting of the glucose oxidase modified polyaniline(PAn/GOD) electrodeis controlled by an unsaturated enzyme kinetics with the rate constant of 1.43×10-7 m·s-1. According to the effect of pH on the maximum response current imax of the electrode, the plot of Ig imax, versus pH shows that two types of ionizing groups are involved in the intermediate of the reaction. The pKlc and pK2c are 4. 9 and 6. 3, respectively. When pKic<pH<pK2c, the glucose oxidase has a high activity. The PAn/GOD electrode still remains a high activity after use of 1200 times and storing for 8 months.