辣根过氧化物酶在表面活性剂膜中的直接电化学

Direct Electrochemistry of Horseradish Peroxidase in Surfactant Films

利用 3种表面活性剂分别将辣根过氧化氢酶固定在裂解石墨棱面 (edge planepyrolyticgraphite ,EPG)电极表面 ,研究了辣根过氧化物酶 (HRP)中Fe /Fe 电对与电极之间的直接电子传递过程以及酶催化双氧水还原过程。实验结果表明 :(1)表面活性剂是一种固定酶的理想材料 ;(2 )这种体系可能构造第三代生物传感器 ,对解释生物体代谢过程具有理论意义 。

The oxidation-reduction properties, relative to the Fe(III)/Fe(II) conversion, of horseradish peroxidase (HRP) in surfactant films at edge-plane pyrolytic graphite (EPG) electrode have been investigated by using direct electrochemical methods. Cyclic voltammograms for DDAB/HRP/CME (chemically modified eelctrode), DMPC/ HRP/CME, DHP/HRP/CME at 2V/s in -phosnhate buffer solution (pH 7. 0) show one pair of reversible, reproducible redox peaks. The redox potentials (E-1/2) in DDAB/HRP/CME, DMPC/HRP/CME and DHP/HRP/ CME are - 0. 212V, - 0. 0330V, - 0. 381V respectively. Experimental result indicated that the membranes, especially the positively charged one, providing special film environment, might interfere in the protein-electrode electron transfer process. The electron transfer processes of HRP were described in the absence and in the presence of hydrogen peroxide. There are good linear relationships between the currents and the H2O2 concentration using all the three CMEs. The results obtained are of potential value for basic and applied bioelectrochemistry and represent an opportunity to build the third generation of biosensors.