科研之友
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摘要
Graphene was coated on glassy carbon electrode and ZnO was then electrodeposited on the modified electrode. The biosensor was fabricated for sensitive determination of glucose after glucose oxidase was immobilized on the modified electrode. Scanning electron microscope was used to characterize the nano. composite film. The electrochemical behaviors of glucose oxidase on the modified electrode were investigated in the range of -0. 7 V to -0. 1 V by cyclic voltammetry. The experimental results demonstrated that the nanocomposite well retained the activity of glucose oxidase and the biosensor exhibited excellent electrocatalytic activity toward the redox of glucose. In 0. 1 mol/L PBS (pH 7. 0), the glucose oxidase adsorbed onto the graphene/ZnO composite film exhibits a pair of well-defined nearly reversible redox peaks and fine catalysis to the oxidation of glucose. The electron transfer rate constant (k(s)) of glucose oxidase at the modified electrode was 1. 42 s(-1), and Michaelis-Menten constant (K-m(app)) was 14. 2 mu mol/L. A good linear relationship was obtained in the range of 2. 5 x 10(-6) - 1. 5 x 10(-3) mol/L, with the limits of detection of 2. 4 x 10(-7) mol/L (S/N = 3). The biosensor has good conductivity, stability and repeatability, and it can be used to analyze real samples.
- 出版日期2013-8
- 单位信阳师范学院
