将键合金丝以螺旋方式紧密绕制在光纤纤芯上,用水浴法在其表面合成氧化锌纳米线,再将葡萄糖氧化酶物理吸附在纳米线上,得到了螺旋线形跨尺度葡萄糖酶电极。提取了该跨尺度结构及相应酶电极的表面形貌,表征了该批酶电极的电化学性能。结果表明,氧化锌纳米线的合成参数对跨尺度结构的表面形貌、葡萄糖氧化酶的固定效果、跨尺度电化学葡萄糖传感器的性能有显著影响;当生长液Zn2+浓度为25 mmol/L时,跨尺度结构表面形貌的粗糙度为0.10μm、相关长度0.29μm,此时葡萄糖氧化酶的固定效果最好,对应的葡萄糖传感器灵敏度为2.15μA/(mmol/L·cm2)、线性范围0~4.5 mmol/L、检出限9.2μmol/L、Michaelis-Menten常数3.68 mmol/L。研究结果不但有助于螺旋线形跨尺度酶电极的批量制备,还可显著提高其测量精度。
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.