Abstract: The invention concerns novel molecular complexes with photoluminescent probes whose specific association with purine-binding proteins leads to increased emission of long lifetime luminescence, and the application of the probes for monitoring activity of protein kinases (PKs) and other purine-binding proteins, screening of compounds as inhibitors of PKs and characterization of inhibitors targeted to the kinase, and methods of manufacturing of such probes. The invention concerns also the use of the improved method for monitoring activity of protein kinases in living cells, characterization of inhibitors of protein kinases, analysis of protein kinase-based disease biomarkers and other tasks of biological and medical importance.