[Study on fluorescence quenching mechanism of HSA-PMA associated nanoparticle system]

In pH 7.40 Tris-HCl buffer solution, PMA is light yellow and has no absorption peak in the visible region. HSA has no color and no absorption peak in the visible region either. There is a fluorescence peak at 350 nm for HSA in pH 7.40 Tris-HCl buffer solution. HSA and PMA can combine into HSA-PMA association nanoparticles with a diameter about 80 nm by means of static gravitation. HSA has both hypochromic and color enhancement effects on PMA through our research. The fluorescence of Trp, Tyr and HSA can be quenched by PMA, but their quenching mechanisms are different. The fluorescence quenching of Trp and Tyr by PMA is due to molecule absorption in the range of emission wavelength, namely because of energy transfer often reported. The investigation results demonstrated that the formation of HSA-PMA associated nanoparticle and interface is the ultimate reason for fluorescence quenching, resonance scattering, and enhanced and hypochromic color.