Determination of bovine serum albumin using resonance light scattering technique with sodium dodecylbenzene sulphonate-cetyltrimethylammonium bromide probe

In this paper, the anionic surfactant sodium dodecylbenzene sulphonate (SDBS) and cationic surfactant cetyltrimethylammonium, bromide (CTMAB) were used as resonance light scattering (RLS) probe to determine bovine serum albumin (BSA). Based on the weak RLS intensity of SDBS-CTMAB probe and the enhancement of RLS intensity of BSA in the presence of the probe, a simple assay for BSA was developed. The experimental results showed that the formation of three component complex BSA-SDBS-CTMAB is the main reason for the enhancement of RLS intensity of BSA, in which SDBS as a bridge can interact with both BSA and CTMAB. The effects of pH value, incubation time, concentrations of SDBS and CTMAB on the enhanced RLS intensity of BSA were investigated. Under the optimum conditions, the enhanced RLS intensity is proportional to the concentration of BSA in the range from 2.5 x 10(-8) to 2.0 x 10(-6) mol L-1. The detection limit is 9.7 x 10(-9) mol L-1 for BSA. The study of foreign substance effect on the determination of BSA indicated that most of metal ions have little effect on the determination of BSA. The results of assay for BSA in synthetic samples were satisfactory. (C) 2006 Elsevier B.V. All rights reserved.