Amperometric thrombin aptasensor using a glassy carbon electrode modified with polyaniline and multiwalled carbon nanotubes tethered with a thiolated aptamer

作者：Su, Zhaohong^*; Xu, Xiaolin; Xu, Haitao; Zhang, Yi; Li, Chaorong; Ma, Yan; Song, Dongcheng; Xie, Qingji^*

来源：Microchimica Acta, 2017, 184(6): 1677-1682.

DOI：10.1007/s00604-017-2164-9

• Amperometric thrombin aptasensor
• Thiol-ene chemistry
• Thiolated aptamer
• Polyaniline-multiwalled carbon nanotubes

A nanocomposite consisting of polyaniline and multiwalled carbon nanotubes was tethered with a thiolated thrombin-specific aptamer and placed on a glassy carbon electrode (GCE) to obtain a biosensor for thrombin that has a limit of detection of 80 fM. Tethering was accomplished via a thiol-ene reaction between thiolated thrombin aptamer (TTA) and oxidized polyaniline (PANI) that was chemically synthesized in the presence of solution-dispersed multiwalled carbon nanotubes (MWCNTs). The modified GCE exhibits a pair of well-defined redox peaks (at 50/-25 mV) of self-doped PANI in neutral solution, and the tethered TTA-thrombin interaction gives a decreased electrochemical signal. Cyclic voltammetry, scanning electron microscopy and ultraviolet visible spectroscopy were used to characterize the film properties. This amperometric aptasensor is sensitive, selective and reproducible. It was applied to the determination of thrombin in spiked human serum (0.2 to 4 nM) and gave recoveries that ranged from 95 to 102%.

• 出版日期2017-6
• 单位湖南师范大学; 湖南农业大学