纳米ZnO增强葡萄糖生物传感器的制备和应用

Fabrication and Application of Glucose Biosensor Enhanced by ZnO Nanoparticles

为提高葡萄糖生物传感器的灵敏度,以纳米ZnO与聚乙烯醇缩丁醛(PVB)构成复合固定酶膜基质,采用溶胶-凝胶法固定葡萄糖氧化酶(GOD),用戊二醛进行交联,制成葡萄糖生物传感器。实验结果表明,GOD可牢固地固定在电极表面,在相同葡萄糖浓度下,加入纳米颗粒的电极的电流响应值比未加颗粒的高约100倍,电极重复使用46次后电流响应值仅下降到初始的70%。电极制备方法简单,易于操作。同时对温度、溶液pH值以及溶剂对电极的影响进行了研究,获得了最优的实验条件。

ZnO nanoparticle has good biocompatibility, and is suitable for enzyme immobilization. In this study, glucose oxidase （GOD） was immobilized in the multiple membrane matrix consisting of ZnO nanoparticles and polyvinyl butyl （PVB） by a sol-gel method on Pt wire substrate, and then linked by glutaradehyde. In this way a glucose biosensor was completed. The amperometric measurement of this biosensor was carried out with a double-electrode system, in which enzyme electrode served as working electrode and Ag/AgCl electrode as reference electrode. A background current in phosphate buffer soluiton, and a response current in glucose solution were obtained. So the difference between background current and response current was the current response of the enzyme electrode. The experiment results showed that GOD was firmly immobilized on the surface of electrode, and the current response was 100 times larger than that without nanoparticles. The current responsemaintained 70% of original response after the electrode was repeatedly used 46 times. The fabrication of electrode is simple and easily operated. Further, it was found that 35℃ and pH 6.8 are the set of optimal parameters for the fabrication of the electrode and the behavior of enzyme electrode appeared fine when mixed solvent of alcohol to isopropanol was 1 ： 1.