Determination of proteins using fluorescence enhancement of Tb3+–benzoylacetone–sodium dodecyl benzene sulfonate–protein system

A new system for the determination of proteins has been developed in this paper. Proteins can enhance the fluorescence intensity of the Tb–benzoylacetone (BA) system in the presence of sodium dodecyl benzene sulfonate (SDBS). Under optimum conditions, the enhanced fluorescence intensity is in proportion to the concentration of proteins in the range of 1.0 × 10−8 to 6.0 × 10−6 g mL−1 for bovine serum albumin (BSA), 3.0 × 10−8 to 6.0 × 10−6 g mL−1 for egg albumin (EA) and 1.0 × 10−8 to 5.0 × 10−6 g mL−1 for human serum albumin (HSA). Their detection limits (S/N = 3) are 3.9 × 10−9, 4.0 × 10−9 and 8.5 × 10−9 g mL−1, respectively. In addition, the interaction mechanism is also investigated.