Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (08): 1727-1734.doi: 10.3866/PKU.WHXB201306042

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

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.

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

MSC2000: 

  • O646