An antifouling electrochemical aptasensor based on hyaluronic acid functionalized polydopamine for thrombin detection in human serum.

Accurate detection of disease markers in a complex biological media is a major challenge because of serious biofouling and non-specific protein adsorption. Herein, a universal strategy for sensitive and low-fouling detection of thrombin in human serum was developed based on hyaluronic acid functionalized polydopamine. The material hyaluronic acid with hydroxyl groups was grafted to the polydopamine modified electrode surface through the connection of 6-mercapto-1-hexanol to exert antifouling performance, and the hyaluronic acid also provided a good substrate for the immobilization of aptamers specific for thrombin. The constructed aptasensor showed good sensitivity and selectivity toward the detection of thrombin with a detection limit as low as 0.03 pM. Moreover, thanks to the presence of hyaluronic acid within the sensing interface, the aptasensor was able to assay thrombin in diluted human serum with markedly decreased side effect of non-specific adsorption.