Facile, sensitive and selective fluorescence turn-on detection of HSA/BSA in aqueous solution utilizing...

A novel fluorescence turn-on detection method of human serum albumin (HSA) and bovine serum albumin (BSA) in aqueous solution is investigated using 2,4-dihydroxyl-3-iodo salicylaldehyde azine (DISA). Upon the addition of DISA to HSA/BSA solution, a fluorescence turn-on effect at 529 nm can be observed with a large stokes shift of approximately 129 nm based on hydrophobic binding-mode between protein and dye. Under the optimal condition, the linear ranges of fluorescence intensity for HSA and BSA are 0.1-30 microg mL(-1) with the relative correlation coefficient of R(2)=0.991 (n=10) and 0.3-50 microg mL(-1) with R(2)=0.997 (n=10); and the detection limits for HSA and BSA based on IUPAC (C(DL)=3S(b)/m) are 20 ng mL(-1) and 50 ng mL(-1), respectively.