生物功能电极 III. 葡萄糖氧化酶的电化学固定化研究

利用磷酸盐缓冲溶液中吡咯的电聚合, 将葡萄糖氧化酶(GOD)包埋在聚吡咯(PPy)基质中以构成生物功能电极。讨论了溶液pH和聚合电位对酶固定化的影响, 并用IR和交流阻抗谱对酶膜进行表征。GOD的固定化只有当pH>5.5时才能实现, 由此推测酶是以带负电的粒子嵌入PPy的。交流阻抗谱表明这一电极具有有界多孔电极的特征。探索了酶与电子传递体Fe(CN)_6~(3-)同时固定化的可行性。电化学固定化的GOD保持其生物催化活性, 酶反应表观上遵循Michealis-Menten动力学。

Biofunctional Electrodes III. Study on Electrochemical Immobilization of Glucose Oxidase

By electrochemical polymerization of pyrrole in phosphate buffer, glucose oxidase (GOD) was entrapped in polypyrrole matrix (PPy) to construct the enzyme electrode. Effects of electropolymerization conditions, such as pH values and electrode potentials, on the enzyme immobilization were studied. Behavior of GOD/PPy membranes was characterized by IR and a.c. impedance spectra. The immobilization of GOD will be accomplished only if pH>5.5. It is likely that GOD enters into PPy in its entity with negative charge. Spectra of a.c. impedance show that the enzyme electrode has the features similar to porous electrodes. It was edmonstrated that the simultaneous immobilization of GOD and mediator Fe(CN)_6~(3-) is feasible. The electrcchemically immobilized GOD maintains its biocatalytic activeties, and apparently the enzymatic reaction follows Michaelis-Menten kinetics.