Biosensors & Bioelectronics
Glucose sensing electrodes have been realized by immobilizing glucose oxidase (GOx) on unmodified edge plane of highly oriented pyrolytic graphite (epHOPG) and the native oxide of heavily doped silicon (SiO2/Si). Both kinds of electrode show direct interfacial electron transfer due to the redox process of the immobilized GOx. The measured formal potential of the redox process agrees with that of the native enzyme, suggesting that the immobilized GOx has retained its enzymatic activity. The electron transfer rates of the GOx immobilized electrode are 2s−1 for GOx/epHOPG electrode and 7.9s−1 for GOx/SiO2/Si electrode, which are greater than those for which GOx is immobilized on modified electrodes, probably due to the fact that the enzyme makes direct contact to electrode surface. The preservation of the enzymatic activity of the immobilized GOx has been confirmed by observing the response of the GOx/epHOPG and GOx/SiO2/Si electrodes to glucose with a detection limit of 0.050mM. The response signals the catalyzed oxidation of glucose and, therefore, confirms that the immobilized GOx retained its enzymatic activity. The properties of the electrode as a glucose sensor are presented.
Wang, Gang; Thai, Ngee Mei; and Yau, Siu-Tung, "Preserved Enzymatic Activity of Glucose Oxidase Immobilized on Unmodified Electrodes for Glucose Detection" (2007). Electrical Engineering & Computer Science Faculty Publications. 56.
Wang, G., Thai, N. M., , & Yau, S. (2007). Preserved enzymatic activity of glucose oxidase immobilized on unmodified electrodes for glucose detection. Biosensors and Bioelectronics, 22(9-10), 2158-2164. doi:10.1016/j.bios.2006.10.015
NOTICE: this is the author’s version of a work that was accepted for publication in Biosensors & Bioelectronics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biosensors & Bioelectronics, 22, 9-10, (04-15-2007); 10.1016/j.bios.2006.10.015