电聚吡咯固定化酪氨酸酶电极的制备及性能

Preparation and Characteristics of a Enzyme Electrode Based on Immobilization of Tyrosinase in Electropolymerized Polypyrrole Film

在应用恒电位法电化学聚合吡咯的同时 ,将酪氨酸酶固定在导电聚吡咯膜内 ,制成一种灵敏、稳定的酪氨酸电极 .讨论了溶液 pH值和聚合电位对酶固定化的影响 ,对酶分子嵌入吡咯膜前后的SEM图和CV曲线进行了分析、比较 .该电极对甲苯酚响应的线性范围为 5 .0× 10 -8～ 1.0× 10 -6mol/L ,最适 pH值为 6 .6 ,酶反应表观上遵循Michaelis_Menten动力学 ,表观米氏常数为 2 .2× 10 -5mol/L .

A sensitive and stable amperometric enzyme electrode was constructed, based on the immobilization of tyrosinase in potentiostatically electropolymerized polypyrrole film at a platinum electrode. The influence of pH and potential on immbilization was discussed. SEM micrographs and CV curves of films obtained before and after incorparation of tyrosinase molecular were analyzed and compared each other. The enzyme electrode responds linearly to p-cresol over a concentration range of 5×10 -8 ～1×10 -6 mol/L with an optimum pH of 6.6, It exhibited kinetic characteristics of the typical enzyme-catalyzed reaction with an apparent Michaelis constant of 2.2 ×10 -5 mol/L.