Abstract:

Highly ordered TiO₂ nanotube arrays (TNA) with controlled pore sizes in a series of 21, 62, 83 and 102 nm were synthesized using constant current oxidization method. Glucose oxidases (GOx) were immobilized on TNA by physical adsorption, and the GOx activities on TNA were investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. All immobilized GOx had good oxidizing activities in glucose solution and GOx on 83 nm-pore-sized TNA showed the best sensibility of 27.2 μA·(mmol·L^-1)^-1·cm^-2, which was probably due to a combination effect of reduced diffusion resistance and small Michaelis constant of the immobilized GOx. The experimental results had demonstrated that controlling pore sizes of TNA could effectively tune sensitivity of glucose biosensors.

Key words: glucose oxidase, TiO₂ nanotube arrays, pore size, diffusion resistance, electrochemistry, biosensor, preparation, bioprocess

摘要：

采用电化学阳极氧化法制备出不同孔径（21、62、83、102 nm）的TiO₂纳米管阵列（TNA），研究了孔径对固定化葡萄糖氧化酶（GOx）的传感器性能的影响。循环伏安测试结果表明固定在不同孔径大小的TNA上的GOx在葡萄糖溶液中均具有良好的酶活性。计时电流法和交流阻抗法测试发现，当孔径是83 nm时，灵敏度达到最大值27.2 μA·（mmol·L^-1）^-1·cm^-2。调控TNA的孔径可改变固定化GOx的活性及溶液扩散阻抗，从而显著提高生物传感器性能。

关键词: 葡萄糖氧化酶, TiO₂纳米管阵列, 孔径, 扩散阻抗, 电化学, 生物传感器, 制备, 生物过程