Fluorometric determination of proteins using the yttrium(III)-sodium lauryl sulfate-rutin-protein system

It is found that rutin can react with yttrium(III) (Y3+), and emits fluorescence of rutin. The intensity is greatly enhanced by proteins in the presence of sodium lauryl sulfate (SLS). Based on this, a new fluorimetric method of determination of proteins is developed. Under optimum conditions, the enhanced intensity of fluorescence is in proportion to the concentration of proteins in the range of 5.0×10−9-1.0×10−5 g/mL for bovine serum albumin (BSA), 3.0×10−8-1.0×10−5 g/mL for human serum albumin (HSA) and 1.0×10−7-2.0×10−5 g/mL for egg albumin (EA). Their detection limits (S/N=3) are 1.6×10−9, 9.8×10−9 and 2.1×10−8 g/mL, respectively. The interaction mechanism is also studied.