TiO_2膜结构调控及葡萄糖传感性能

Structural control of TiO_2 film and its glucose sensing performance

以钛酸四丁酯为前驱体、聚乙二醇(PEG)为模板剂,通过调节加入溶胶中模板剂的相对分子质量实现TiO2膜微观形貌的调控。X线衍射(XRD)结果表明制备的DENSE、PEG-600和PEG-1000 3种膜均为TiO2锐钛晶型。通过场发射扫描电子显微镜(FESEM)及N2吸附-脱附表征发现:无模板剂加入的TiO2膜呈现平整致密形貌,加入平均相对分子质量为600及1 000的聚乙二醇后,制备的TiO2膜分别呈现规则纳米颗粒及纳米介孔结构表面。将3种TiO2膜固定化葡萄糖氧化酶并制备成电极后,无需加入氧化还原媒介体,均可对溶液中葡萄糖产生直接电化学响应。葡萄糖传感测试发现具有介孔结构的TiO2膜电极具有较好的灵敏度(5.95 mA·L/(mol·cm2))及电活性蛋白密度(1.63×10-11mol/cm2),具有纳米颗粒结构TiO2膜电极的葡萄糖传感性能次之,表明TiO2材料的微观形貌对葡萄糖传感性能影响显著,具有介孔结构的TiO2膜在生物传感领域具有潜在的应用价值。

TiO2 films were synthesized using template-assisted sol-gel method with tetrabutyl titanate as precursor and polyethylene glycol （PEG） as template.Film structures were controlled by adjusting the molecular weight of PEG.X-ray diffraction （XRD） results showed that the TiO2 films were anatase phase.Field emission scanning electron micrography （FESEM） and N2 adsorption-desorption isotherm analysis indicated that the as-synthesized TiO2 films exhibited dense,nanoparticle and mesoporous morphology,respectively.After immobilized with glucose oxidase （GOx）,the fabricated TiO2 film electrodes showed fast direct electron transfer between GOx molecules and electrode surface without redox mediate.The mesoporous TiO2 film electrode had a high sensitivity of 5.95 mA· L/（mol· cm^2） and protein density of 1.63 × 10-11 m-l/cm^2,higher than other TiO2 film electrodes.It was confirmed that the micromorphology of TiO2 film could make real influence on glucose sensing performance and TiO2 film with mesoporous structure had good application in glucose biosensor.