Water-Soluble BODIPY-Based fluorescent probe for BSA and HSA detection

Interaction of 4,4-difluoro-1,3,7,8-tetramethyl-2,6-disulfo-4-bora-3a,4a-diaza-s-indacene sodium salt (BODIPY, BP1) with bovine serum albumin (BSA) and human serum albumin (HSA) was investigated using spectral methods and molecular docking. It was shown that BP1 forms stable supramolecular complexes with BSA and HSA predominantly due to the specific interactions. Supramolecular complex formation was accompanied by strong fluorescence quenching of BP1 as a result of FRET. This effect could be used for the qualitative and quantitative detection of HSA in model physiological fluids. The detection limit of BSA and HSA were 0.26 and 0.05 mg·mL−1, respectively. The selectivity of BP1 fluorescence response to the co-presence of BSA and HSA in solution was demonstrated. The BP1 fluorescent probe was successfully used for the qualitative and quantitative detection of HSA in human urine samples. The obtained results indicated the capability of using BP1-based fluorescent sensors in clinical medicine for early detection of microalbuminuria and concomitant diseases.