Fluorescence enhancement effect of the morin–Al 3+ –sodium dodecyl benzene sulphonate–protein system and the determination of proteins

The fluorescence intensity of the morin–Al 3+ complex was greatly enhanced by proteins in the presence of sodium dodecyl benzene sulphonate (SDBS). Based on this, a new fluorimetric method for the determination of protein was developed. Under optimum conditions, the enhanced intensity of fluorescence was in proportion to the concentration of proteins in the range 1.0 × 10 −8 –1.3 × 10 −5 g/mL for bovine serum albumin (BSA), 4.0 × 10 −8 –1.2 × 10 −5 g/mL for egg albumin (EA) and 5.0 × 10 −8 –1.2 × 10 −5 g/mL for human serum albumin (HSA). Their detection limits (S:N = 3) were 5.0 × 10 −9 , 1.8 × 10 −8 and 1.6 × 10 −8 g/mL, respectively. The interaction mechanism was also studied. Copyright © 2005 John Wiley & Sons, Ltd.