Thrombin Bionsensors: A Rapid and Ultrasensitive Thrombin Biosensor Based on a Rationally Designed Trifunctional Protein (Adv. Healthcare Mater. 12/2020)

In article number 2000364 by Yanyan Wang, Zefang Wang, and co-workers, an ultrasensitive and rapid thrombin biosensor is developed based on rationally designed trifunctional protein HTs, comprising three functional units, including a far-red fluorescent protein smURFP, hydrophobin HGFI, and a thrombin cleavage site (TCS). smURFP is used as a detection signal to eliminate any interference from the autofluorescence of sample matrix to increase detection sensitivity. HGFI serves as an adhesive unit to allow rapid immobilization of HTs on a multiwall plate. The TCS linking HGFI and smURFP functions as a sensing element to recognize and detect thrombin. As a result, the intensity of the fluorescent signal on the surface of multiwall plates changes depending on the concentration of thrombin. The sensing mechanism of this biosensor relies on the ability of active thrombin in samples to specifically recognize and hydrolyze its cleavage site in the fusion protein, resulting in a subsequent decrease in the fluorescence intensity of the sample.