Abstract
The amperometric bienzyme glucose biosensor utilizing horseradish peroxidase (HRP) and glucose oxidase (GOx) immobilized in poly(toluidine blue O) (PTBO) film was constructed on multi-walled carbon nanotube (MWNT) modified glassy carbon electrode. The HRP layer could be used to analyze hydrogen peroxide with toluidine blue O (TBO) mediators, while the bienzyme system (HRP + GOx) could be utilized for glucose determination. Glucose underwent biocatalytic oxidation by GOx in the presence of oxygen to yield H 2O2 which was further reduced by HRP at the MWNT-modified electrode with TBO mediators. In the absence of oxygen, glucose oxidation proceeded with electron transfer between GOx and the electrode mediated by TBO moieties without H2O2 production. The bienzyme electrode offered high sensitivity for amperometric determination of glucose at low potential, displaying Michaelis-Menten kinetics. The bienzyme glucose biosensor displayed linear response from 0.1 to 1.2 mM with a sensitivity of 113 mA M -1 cm-2 at an applied potential of -0.10 V in air-saturated electrolytes.
Original language | English |
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Pages (from-to) | 7055-7060 |
Number of pages | 6 |
Journal | Electrochimica Acta |
Volume | 55 |
Issue number | 23 |
DOIs | |
Publication status | Published - 30 Sept 2010 |
User-Defined Keywords
- Bienzyme glucose biosensor
- Carbon nanotubes
- Poly(toluidine blue O)
- Reaction mechanism