Study of the interaction of proteins with curcumin and SDS and its analytical application

It is found that protein and sodium dodecyl sulphonate (SDS) can enhance resonance light scattering (RLS) of curcumin (CU). Based on this phenomenon, a new quantitative method for protein in aqueous solution has been developed. In the BR (pH 3.5) buffer, the RLS intensity of CU–SDS system is greatly enhanced by protein. The enhanced RLS is proportional to the concentration of protein in the range of 0.00020–20.0 μg ml−1 for bovine serum albumin (BSA) and 0.00040–1.0 μg ml−1 for human serum albumin (HSA) and their detection limits are 0.16 and 0.041 ng ml−1, respectively. An actual sample is satisfactorily determined. In addition, the interaction mechanism between protein and CU–SDS is also studied by using multi-techniques such as RLS, absorption spectroscopy and fluorescence, zeta potential assay measurement.