2.Relationship Between Surface Morphology and Performance of a Spirally Hierarchical Structure-based Electrochemical Glucose Sensor
Weixuan JING ; Fan ZHOU ; Yanyan CHENG ; Han QI ; Lujia CHEN ; Zhuangde JIANG ; Bing WANG
Chinese Journal of Analytical Chemistry 2014;(8):1077-1082
Zinc oxide nanowires were hydrothermally synthesized on the surface of an Au cylindrical spiral formed by manually spiraling an Au fiber around an optical fiber core, glucose oxidase was immobilized on these nanowires by physical adsorption, and then a spirally hierarchical structure-based glucose enzymatic electrode was obtained. The surface morphologies of the spirally hierarchical structures and corresponding enzymatic electrodes were extracted, and the electrochemical performances of the enzymatic electrodes were characterized. It was concluded that the synthesizing parameters of zinc oxide nanowires significantly affected the surface morphologies and glucose oxidase immobilization on the spirally hierarchical structures, and further the performances of related glucose sensors. With Zn2﹢concentration of the growth solution set at 25 mmol/L, the roughness of surface morphology was determined to be 0. 10 μm and correlation length 0. 29 μm, resulting in a better immobilization of glucose oxidase upon zinc oxide nanowires. In this case the sensitivity of the glucose sensor was determined to be 2. 15 μA/(mmol/L·cm2), the linear range was 0-4. 50 mmol/L, the low detection limit was 9. 20 μmol/L and Michaelis-Menten constant was 3. 68 mmol/L. The results not only benefit the batch production of the spirally hierarchical structure-based enzymatic electrodes, but also significantly improve the performances of the glucose sensors.