Fluorescence Resonance Energy Transfer Between Calcein and Phloxine in Micellar Media
Fluorescence resonance energy transfer(FRET) from calcein to phloxine and the application for determining protein was studied.FRET of calcein-phloxine occurred most effectively in aqueous polyvinyl alcohol micellar solutions with HAc-NaAc buffer solution(pH=5.30).The mechanism of the FRET between calcein and phloxine was investigated.The results showed that the fluorescence of calcein-phloxine system was quenched by adding protein,and there were good linear correlations between the concentrations of protein and the fluorescence quenched intensities.Then a new determination strategy of protein was built by using the calcein-phloxine system.Under optimum conditions,the linear range of determining bovine serum albumin was 0.4-84 mg/L,with a detected limit of 0.2 mg/L(n=11).The method could be applied to determine the total protein content for the samples of human serum,with RSD1.8%(n=6) and the recovery of standard addition was 96.9%-102.1%.