Facile, sensitive and selective fluorescence turn-on detection of HSA/BSA in aqueous solution utilizing 2,4-dihydroxyl-3-iodo salicylaldehyde azine

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 ∼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 μg mL−1 with the relative correlation coefficient of R2 = 0.991 (n = 10) and 0.3–50 μg mL−1 with R2 = 0.997 (n = 10); and the detection limits for HSA and BSA based on IUPAC (CDL = 3Sb/m) are 20 ng mL−1 and 50 ng mL−1, respectively.