化学学报 ›› 2004, Vol. 62 ›› Issue (3): 335-340. 上一篇    下一篇

研究简报

碳纳米管电极上辣根过氧化物酶的直接电化学

蔡称心, 陈静   

  1. 南京师范大学化学系, 南京, 210097
  • 投稿日期:2003-09-15 修回日期:2003-11-29 发布日期:2014-01-26
  • 通讯作者: 蔡称心,E-mail:cxcai@njnu.edu.cn. E-mail:cxcai@njnu.edu.cn
  • 基金资助:
    国家自然科学基金(No.20373027)、教育部留学回国人员启动基金、江苏省高校自然科学基金(No.03KJA150055)和江苏省南京市人事局回国人员择优项目资助课题.

Direct Electrochemistry of Horseradish Peroxidase at a Carbon Nanotube Electrode

CAI Chen-Xin, CHEN Jing   

  1. Department of Chemistry, Nanjing Normal University, Nanjing 210097
  • Received:2003-09-15 Revised:2003-11-29 Published:2014-01-26

制备了碳纳米管修饰玻碳电极(CNT/GC).将辣根过氧化物酶(HRP)固定在CNT/GC电极表面,形成HRP-CNT/GC电极.研究了HRP的直接电子转移.实验结果表明,HRP在CNT/GC电极表面能进行有效和稳定的直接电子转移反应,其循环伏安曲线上表现出一对良好的、几乎对称的氧化还原峰;式量电位E0'几乎不随扫速(至少在20~100 mV/s的扫速范围内)而变化,其平均值为(-0.319±0.002) V (vs. SCE, pH 6.9); HRP在CNT/GC电极表面直接电子转移的速率常数为(2.07±0.56) s-1;式量电位E0'与溶液pH 的关系表明HRP的直接电化学是(1e+1H+)的电极过程.进一步的实验结果显示,固定在CNT/GC电极表面的HRP能保持其对H2O2还原的生物电催化活性,而且能快速地响应H2O2浓度的变化.本文制备碳纳米管修饰电极和固定酶的方法具有简单和易于操作等优点,可用于获得其它生物氧化还原蛋白质和酶的直接电子转移.

关键词: 碳纳米管, 修饰电极, 直接电化学, 辣根过氧化物酶

Horseradish peroxidase (HRP) immobilized on the surface of the carbon nanotube modified glassy carbon electrode (HRP-CNT/GC) can undergo effective and stable direct electron transfer reaction. The cyclic voltammetric results indicate that the HRP-CNT/GC electrode exhibits a pair of well-defined and nearly symmetrical redox peaks in 0.1 mol/L phosphate buffer solution. Its formal redox potential, E0', is almost independent on the scan rates, the average value of E0' is (-0.319±0.002) V (vs. SCE, pH 6.9) in the phosphate buffer solution (pH 6.9) in the scan rate range of 20~100 mV/s. The dependence of E0' on the pH of the buffer solution indicates that the direct electron transfer of HRP is a one-electron-transfer reaction process coupled with one-proton-transfer. The experimental results also demonstrated that the immobilized HRP retained its bioelectrocatalytic activity for the reduction of H2O2 and the HRP-CNT/GC electrode can rapidly respond to the change of the concentration of H2O2. The method presented here can be easily extended to obtain the direct electrochemistry of other redox enzymes or proteins.

Key words: carbon nanotube, chemically modified electrode, direct electrochemistry, horseradish peroxidase