Science, Technology, Engineering and Mathematics (STEM-UniSA), University of South Australia, Adelaide, SA 5095, Australia.
Future Industries Institute, University of South Australia, Adelaide, South Australia 5095, Australia.
J Nanosci Nanotechnol. 2021 Sep 1;21(9):4605-4614. doi: 10.1166/jnn.2021.19324.
An electrochemical biosensor for the detection of glucose is realized by immobilizing glucose oxidase (GOx) enzyme onto titanium dioxide nanotube arrays by a coupling encapsulation process. We present details of a robust fabrication technique that results in a durable and reproducible sensor characteristics. The TiO₂ nanotube arrays are grown directly on a titanium substrate by a potentiostatic anodization process in a water and ethylene-glycol mixture solution, which contains ammonium fluoride. An electropolymerization process was also performed to enhance interfacial adhesion between GOx and TiO₂ nanotubes. Detection of glucose concentrations was achieved with a linear response in the range of 0.01 to 0.2 mM. Investigation of enhanced sensitivity by increasing the count, the length, and the cross-section of the nanotubes was also carried out. Surface morphologies of Ti substrate were examined by scanning electron microscopy to optimize the anodization process and thus the TiO₂/Ti nanotube dimensions. We utilized a time-based amperometric response for the quantitative determination of hydrogen peroxide concentration through electro-reduction reaction with a bare TiO₂/Ti nanotube-array electrodes, thus providing a reference for the determination of glucose levels with a GOx-coated TiO₂/Ti nanotube array electrodes. Detection levels down to 5.2 M were recorded.
通过将葡萄糖氧化酶（GOx）酶通过偶联封装过程固定在二氧化钛纳米管阵列上，实现了用于检测葡萄糖的电化学生物传感器。我们介绍了一种稳健的制造技术的详细信息，该技术可产生耐用且可重复的传感器特性。TiO₂纳米管阵列通过在水和乙二醇混合物溶液中进行恒电位阳极氧化过程直接在钛基底上生长，该溶液中含有氟化铵。还进行了电聚合过程以增强 GOx 和 TiO₂纳米管之间的界面附着力。通过在 0.01 至 0.2 mM 的范围内实现线性响应来检测葡萄糖浓度。还通过增加纳米管的数量，长度和横截面来研究了提高灵敏度的效果。通过扫描电子显微镜检查 Ti 基底的表面形态，以优化阳极氧化过程，从而优化 TiO₂/Ti 纳米管的尺寸。我们利用基于时间的安培响应来通过与裸露的 TiO₂/Ti 纳米管阵列电极的电还原反应定量测定过氧化氢浓度，从而为用涂覆有 GOx 的 TiO₂/Ti 纳米管阵列电极测定葡萄糖水平提供了参考。记录到的检测水平低至 5.2 M。
