基于纳米二氧化钛的光致电化学适体传感器

Photoelectrochemical aptasensor based on TiO_2 nanoparticles for thrombin detection

该论文旨在运用光致电化学分析技术构建一种准确灵敏的适体传感器。将具有优异光电性质、光电催化特性的纳米二氧化钛(TiO_2NPs)修饰在电极上,于37℃下烘干,然后电沉积一层纳米金(Au NPs),通过Au-N键很好地固载凝血酶适体链(TBA)。TBA孵育过夜后,用封闭剂巯基己烷(HT)封闭非特异性结合位点。利用凝血酶(TB)和TBA的特异性结合,将TB固载到电极上。由此形成了一种高准确度、高灵敏度的光致电化学适体传感器,并用于检测凝血酶。该适体传感器除了操作简单以外,还具有测定准确、灵敏、选择性好的特点。实验表明,该适体传感器在凝血酶的测定上具有良好的线性关系,线性范围为0.01pmol/L^10 nmol/L,检测限为3.33 fmol/L。

This paper aims to construct an accurate and sensitive aptasensor by using photoelectrochemical analysis. TiO2 nanoparticles（TiO2 NPs） with excellent photoelectric properties and photoelectrocatalytic properties were modified on the electrodes, dried at 37 ℃, and then electrodeposit a layer of Au nanoparticles（Au NPs）, The thrombin aptamer chain（TBA） was well immobilized on the electrode by Au-N bonds between Au NPs and TBA.After TBA was incubated overnight, the nonspecific binding site was blocked with the blocking agent mercaptohexane（HT）. TB was immobilized on the electrodes using the specific binding of thrombin（TB） and TBA.Then a highly accurate, highly sensitive photoelectrochemical aptasensor was formed, and was used to detect thrombin. The aptasensor not only has the merit of simplified operation, but also has the determination of accurate,sensitive and high selectivity characteristics. These are due to the excellent photoelectric properties of Ti O2 NPs and the specific binding of TBA to TB. The results showed that the aptasensor had a good linearity in the detection of thrombin, the linear range was 0.01 pmol/L ~ 10 nmol/L, and the detection limit was 3.33 fmol/L.