基于聚吡咯的胆固醇电化学生物传感器的制备及性能研究

Development and Properties of a Polypyrrole-based Electrochemical Biosensor for Cholesterol Detection

摘要:

本文以胆固醇氧化酶和辣根过氧化物酶为催化剂，通过电化学聚合吡咯单体，制备了电流型胆固醇传感器。实验中采用电化学聚合方法制备了聚吡咯膜(PPY)，用扫描电子显微镜(SEM)对聚吡咯膜进行微观结构表征，采用循环伏安(CV)法研究了传感器的电化学特性及其抗干扰能力。结果表明，聚合圈数为300圈时得到的聚吡咯膜制备的传感器性能最佳，传感器最佳工作pH值为8.0，胆固醇氧化酶浓度为30 mg/mL，辣根过氧化物酶浓度为20 mg/mL，制备的胆固醇传感器，具有良好的检测性能，线性范围为2.0×10-6~1.6×10-4 mol/L，表观米氏常数 为5.6×10-6 mol/L，葡萄糖、抗坏血酸、尿酸等组分对传感器响应电流的影响分别为8.1%、8.5%、10.8%，抗干扰效果较好。该传感器对胆固醇具有良好的选择性响应，可以用于胆固醇含量的测定。

Abstract:

A novel, current-based cholesterol biosensor was produced by electrochemical polymerization of pyrrole monomers, using cholesterol oxidase (ChOx) and horseradish peroxidase (HRP) as catalysts. Polypyrrole (PPY) was prepared by electrochemical polymerization and the microstructure of the PPY film was characterized by scanning electron microscopy (SEM). The electrochemical characteristics and anti-interference capacity of the biosensor were evaluated by cyclic voltammetry (CV). The results of this analysis revealed that the PPY film obtained after 300 polymerization circles had optimum sensor performance. The biosensor displayed optimal operation at a pH of 8.0 and showed good detection performance at cholesterol oxidase and horseradish peroxidase concentrations of 30 and 20 mg/mL, respectively. The biosensor displayed a linear range of 2.0 × 10-6 to 1.6 × 10-4 mol/L and an apparent Michaelis-Menten constant ( ) of 5.6 × 10-6mol/L. The biosensor also exhibited excellent anti-interference activity after the addition of glucose, ascorbic acid (AA), and uric acid (UA), which affected the current by 8.1%, 8.5%, and 10.8%, respectively. The cholesterol biosensor exhibited good selective response to cholesterol, and can, therefore, be used in the determination of cholesterol content.