Mediator-free amperometric determination of glucose based on direct electron transfer between glucose oxidase and an oxidized boron-doped diamond electrode.
A mediator-free glucose biosensor, termed a "third-generation biosensor," was fabricated by immobilizing glucose oxidase (GOD) directly onto an oxidized boron-doped diamond (BDD) electrode. The surface of the oxidized BDD electrode possesses carboxyl groups (as shown by Raman spectra) which covalently cross-link with GOD through glutaraldehyde. Glucose was determined in the absence of a mediator used to transfer electrons between the electrode and enzyme. O2 has no effect on the electron transfer. The effects of experimental variables (applied potential, pH and cross-link time) were investigated in order to optimize the analytical performance of the amperometric detection method. The resulting biosensor exhibited fast amperometric response (less than 5 s) to glucose. The biosensor provided a linear response to glucose over the range 6.67x10(-5) to 2x10(-3) mol/L, with a detection limit of 2.31x10(-5) mol/L. The lifetime, reproducibility and measurement repeatability were evaluated and satisfactory results were obtained.
Wu
Jing
J
Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China. wujing1974@mail.hzau.edu.cn
Qu
Yang
Y
D015374:Biosensing Techniques / Q000379:methods*; D001895:Boron; D018130:Diamond; D004563:Electrochemistry; D004566:Electrodes; D004579:Electron Transport; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000378:metabolism*; D010084:Oxidation-Reduction
D018130:Diamond; D005949:Glucose Oxidase; D005947:Glucose; D001895:Boron