A paper-based lateral flow sensor for the detection of thrombin and its inhibitors.

Thrombin is a biomarker of blood-related diseases. Its detection and inhibitor screening are of great significance in the fields of medical and biological research. Herein, a novel paper-based lateral flow sensor for thrombin detection and inhibitors screening is developed. The formation of cross-links of fibrin from fibrinogen during the blood clotting process can efficiently capture water molecules. Based on the principle, in the presence of thrombin, the water of the plasma solution cannot flow along with the test paper as the water molecules are trapped in the fibrin. Upon the inactivation of thrombin by the inhibitors, water can flow along the test paper. The detection limit of thrombin reaches about 16.1 mU/mL and the sensing platform also exhibits excellent selectivity, reproducibility, and stability. Furthermore, the inhibition efficiency of argatroban, a clinical drug used as a thrombin inhibitor, is also successfully investigated using the assay. Overall, this strategy exhibits the advantages of the specific enzymatic reaction, low-cost, and label-free detection of thrombin with high sensitivity and remarkable specificity. This method is also competent to facilitate the screening of thrombin inhibitors, which is promising in the discovery of therapeutic drugs for thrombus-related diseases.