物理化学学报 >> 2013, Vol. 29 >> Issue (08): 1727-1734.doi: 10.3866/PKU.WHXB201306042

电化学和新能源 上一篇    下一篇

纳米材料修饰电极上吸附态葡萄糖氧化酶的酶活性和电活性的比较

杨大威, 陈超, 谢青季, 姚守拙   

  1. 湖南师范大学化学化工学院, 化学生物学及中药分析教育部重点实验室, 长沙 410081
  • 收稿日期:2013-03-23 修回日期:2013-06-04 发布日期:2013-07-09
  • 通讯作者: 谢青季 E-mail:xieqj@hunnu.edu.cn
  • 基金资助:

    国家自然科学基金(21175042, 21075036);湖南省教育厅(11A069)和湖南省高校科技创新团队资助项目

Comparison of Enzymatic Activities and Electroactivities of Adsorbed Glucose Oxidase on Several Nanomaterial-Modified Electrodes

YANG Da-Wei, CHEN Chao, XIE Qing-Ji, YAO Shou-Zhuo   

  1. College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Changsha 410081, P. R. China
  • Received:2013-03-23 Revised:2013-06-04 Published:2013-07-09
  • Contact: XIE Qing-Ji E-mail:xieqj@hunnu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21175042, 21075036), Hunan Provincial Educational Department, China (11A069), and Program for Science and Technology Innovative Research Team in Higher Educational Institutions Hunan Province, China.

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摘要：

采用石英晶体微天平(QCM)技术, 监测了裸金(Au)电极、电沉积纳米金的金电极(Aued/Au)、多壁碳纳米管(MWCNTs)修饰的金电极(MWCNTs/Au)以及MWCNTs 修饰后再电沉积纳米金的金电极(Aued/MWCNTs/Au)上葡萄糖氧化酶(GOx)的吸附过程, 测算了吸附固定的GOx质量. 通过阳极恒电位检测吸附酶与葡萄糖发生酶反应所产生的过氧化氢, 考察了这些酶电极的安培响应, 并测算了各吸附态GOx的质量比生物活性(MSBAi).也通过循环伏安法研究酶的直接电化学, 测算了各吸附态GOx的电活性百分数(EAPi). 实验结果表明, 酶吸附量和酶电极的安培响应满足MWCNTs/Au > Aued/MWCNTs/Au > Aued/Au > Au 的顺序; MSBAi满足Au > Aued/MWCNTs/Au > Aued/Au > MWCNTs/Au的顺序; 而EAPi则满足MWCNTs/Au > Aued/MWCNTs/Au > Aued /Au > Au的顺序. 根据酶和纳米材料的亲疏水作用以及酶的吸附量对实验结果进行了合理解释, 也定量验证了电极上吸附酶分子的总生物活性与酶电极的安培响应呈正相关关系, 所得数据和结论有助于纳米材料固定酶及其安培酶电极的研究.

关键词: 石英晶体微天平, 葡萄糖氧化酶, 质量比生物活性, 电活性百分数, 多壁碳纳米管, 电沉积纳米金

Abstract:

The quartz-crystal microbalance technique was used to monitor the adsorption of glucose oxidase (GOx) on bare Au, Au-electrodeposited Au (Aued/Au), multiwalled carbon nanotube (MWCNT)- modified Au (MWCNTs/Au), and Au-electrodeposited MWCNT-modified Au (Aued/MWCNTs/Au) electrodes. The mass of GOx at saturated adsorption was obtained in each case. The amperometric responses of these enzyme electrodes were examined, and the mass-specific bioactivities of the immobilized (adsorbed) GOx (MSBAi) were evaluated through anodic potentiostatic detection of enzymatically generated H2O2 in the presence of glucose. The direct electrochemistry of adsorbed GOx was studied by cyclic voltammetry, to obtain the electroactivity percentage of the immobilized (adsorbed) GOx (EAPi) in each case. We found that the amounts of enzyme adsorbed and the amperometric responses of these enzyme electrodes follow the order MWCNTs/Au > Aued/MWCNTs/Au > Aued/Au > Au; MSBAi follows the order of Au > Aued/MWCNTs/Au > Aued/Au > MWCNTs/Au; and EAPi follows the order of MWCNTs/Au > Aued/MWCNTs/Au > Aued/Au > Au. The experimental data are interpreted based on hydrophobic/hydrophilic interactions among enzyme molecules and the nanomaterials, as well as the amount of adsorbed GOx. It was also verified that the total enzymatic activity of all the electrode-adsorbed enzyme molecules is positively related to the amperometric responses of the enzyme electrodes. This work is useful in studying the immobilization of enzyme on nanomaterials and thus-prepared amperometric enzyme electrodes.

Key words: Quartz crystal microbalance, Glucose oxidase, Mass-specific bioactivity, Electroactivity percentage, Multiwalled carbon nanotubes, Electrodeposition of Au nanoparticles