本文采用荧光光谱法研究了磷酸缓冲溶液(PBS,pH 7.2)中有无金纳米粒子(AuNP)共存时槲皮素(Qct)与牛血红蛋白(BHb)的相互作用,评估了共存AuNP对Qct和BHb的荧光猝灭效应及对Qct-BHb作用的影响。测得了不同温度下Qct-BHb结合反应的平衡常数K和结合摩尔比n,并由所得热力学常数确定了结合的作用力类型。根据Foerster偶极-偶极无辐射能量转移理论,求得了Qct—BHb作用的分子间距离r=2.68nm和能量转移效率E=0.232。
The interaction between quercetin (Qct) and bovine hemoglobin (BHb) was studied in 0. 1 mol·L^-1 phosphate buffer solutions (PBS, pH 7. 2) with and without coexisting Au nanoparticles (AuNP) by fluorescence spectroscopy, and the effects of AuNP on the fluorescence of BHb and Qct as well as the BHb-Qct interaction were evaluated. The apparent binding constants (K) and molar binding ratio (n) for Qct-BHb interactions in the PBS were measured versus the solution temperature via nonlinear fitting of the experimental data. Thermodynamic constants for the Qct-BHb interaction were measured, and the interaction forces are discussed. The binding distance and energy transfer efficiency were obtained by Foerster non-radiation energy transfer mechanism.