葡萄糖氧化酶在活性炭上的固定及直接电化学

Direct Electrochemistry of Glucose Oxidase Immobilized on Surface of Activated Carbon

The glucose oxidase (GOD) immobilized onto the surface of activated ca rbon powders at the glassy carbon electrode (GOD-C/GC) could undergo the quasi-r eversible, direct electrochemical reaction. Its formal redox potential, E0′, is almost independent on the scan rates. The average value of E0′ is (-0.467 ± 0 .002) V (vs SCE) in the pH 6.8 phosphate buffer solution. Its apparent heterogen eous electron transfer rate constant (ks) is (1.18 ± 0.59) s-1, which is much h igher than that reported previously. The dependence of E0′ on the pH of the buf fer solution indicated that the direct electrochemical reaction of the immobiliz ed GOD is a two-electron transfer reaction process coupled with two-proton trans fer. The further experimental results demonstrated that the immobilized GOD reta ined its bioelectrocatalytic activity to the oxidation of β-D(+) glucose.

The glucose oxidase (GOD) immobilized onto the surface of activated carbon powders at the glassy carbon electrode (GOD-C/GC) could undergo the quasi-reversible, direct electrochemical reaction. Its formal redox potential, E-0', is almost independent on the scan rates. The average value of E-0' is (-0.467 +/- 0.002) V (vs SCE) in the pH 6.8 phosphate buffer solution. Its apparent heterogeneous electron transfer rate constant (k(s)) is (1.18 +/- 0.59) s(-1), which is much higher than that reported previously. The dependence of E-0' on the pH of the buffer solution indicated that the direct electrochemical reaction of the immobilized GOD is a two-electron transfer reaction process coupled with two-proton transfer. The further experimental results demonstrated that the immobilized GOD retained its bioelectrocatalytic activity to the oxidation of beta-D(+) glucose.