Ultrasensitive determination of thrombin by using an electrode modified with WSe2 and gold nanoparticles, aptamer-thrombin-aptamer sandwiching, redox cycling, and signal enhancement by alkaline phosphatase

作者：Wang, Yi-Han; Xia, Huan; Huang, Ke-Jing^*; Wu, Xu; Ma, Ying-Ying; Deng, Rui; Lu, Yun-Fei; Han, Zi-Wei

来源：Microchimica Acta, 2018, 185(11): 502.

DOI：10.1007/s00604-018-3028-7

• Tungsten diselenide nanosheets
• Electrochemical biosensor
• Sandwiched structure
• Protein
• Signal enhancement

A sensitive aptamer/protein binding-triggered sandwich assay for thrombin is described. It is based on electrochemical-chemical-chemical redox cycling using a glassy carbon electrode (GCE) that was modified with WSe2 and gold nanoparticles (AuNPs). The AuNPs are linked to thrombin aptamer 1 via Au-S bonds. Thrombin is first captured by aptamer 1 and then sandwiched through the simultaneous interaction with AuNPs modified with thrombin-specific aptamer 2 and signalling probe. Subsequently, the DNA-linked AuNP hybrids result in the capture of streptavidin-conjugated alkaline phosphatase onto the modified GCE through the specific affinity reaction for further signal enhancement. As a result, a linear range of 0-1 ng mL(-1) and a detection limit as low as 190 fg mL(-1) are accomplished. The specificity for thrombin is excellent. Conceivably, this strategy can be easily expanded to other proteins by using the appropriate aptamer.

• 出版日期2018-11
• 单位信阳师范学院