Preparation of Thrombin Aptamer Sensor Based on Host Guest Competition Model / 分析化学

ABSTRACT

A switch thrombin aptamer sensor was constructed based on the host-guest competition mode ofβ-cyclodextrin (β-CD ) . The aptamer that modified with ferrocene ( Fc ) at its terminal was fixed on the surface of the gold electrode via the host-guest recognization with β-CD. When thrombin was present, the configuration of aptamer transformed from vertical linear to "G-quadruplex" and far away from the electrode surface, which resulted in a decrease in the redox current of the aptamer probe and produce "Signal-off"effect. On the basis of this, a high sensitive detection of thrombin was made. The detection result indicated that the thrombin concentration had a consideration linear response to the signal of aptasensor between 5 . 0 × 10-13-5. 0 × 10-9 mol/L, and as low as 2. 0 × 10-13 mol/L thrombin had been detected. This method for thrombin detection showed a higher specificity compared to other protein molecules. Besides, the sensor was constructed easily and possessed excellent regeneration, which provided a significant platform for highly efficient real-time detection of thrombin in biological serum samples.