Label-free optical biosensor with microfluidics for sensing ligand-directed functional selectivity on trafficking of thrombin receptor

Ligand-directed functional selectivity has stimulated much interest in the molecular delineation of drug pharmacology and the process of drug discovery. Here we describe the development of a label-free optical biosensor with microfluidics for whole cell sensing. The microfluidics controls the duration of agonist exposure and of the functional recovery of activated protease activated receptor-1 (PAR1). The biosensor manifests that the persistency of PAR1 signaling is dependent on the agonists, which, in turn, affects the receptor resensitization process. This study demonstrates a new means to differentiate ligand-directed functional selectivity on trafficking of receptors.