中文摘要：

采用紫外-可见吸收光谱、荧光光谱研究牛血红蛋白（bovinehemoglobin,简称BHb）与纳米雄黄的相互作用。从紫外-可见吸收光谱可观察到,随着纳米雄黄浓度的增加,牛血红蛋白406nm附近的特征Soret吸收带红移至413nm,且强度逐渐降低。强度的降低表明纳米雄黄可能使部分血红素辅基逐渐从它们的键腔中脱离出来。特征峰位的红移推测为纳米雄黄中的砷结合了血红蛋白中的氧,诱导血红蛋白脱氧,变成脱氧血红蛋白,其构象由R态转变成T态。由荧光光谱研究可以得出随着纳米雄黄浓度的增加,牛血红蛋白338nm处的荧光强度逐渐减弱,Stern-Volmer方程分析表明,纳米雄黄静态猝灭牛血红蛋白的内源荧光。紫外-可见吸收光谱与荧光光谱的计算结果均表明,牛血红蛋白与纳米雄黄的结合常数k的数量级达到109。

英文摘要：

In the present paper, the interaction of bovine hemoglobin （BHb） and realgar nanoparticles has been investigated by ultraviolet-visible （UV-Vis） and fluorescence spectroscopy. The Soret band of oxygen-BHb at 406 nm shifted to 413 nm, and its absorption intensity decreased gradually after adding realgar nanoparticles. The Soret band decreases gradually with the increas- ing the amount of realgar NPs, suggesting the detachment of some heine chromophores from their matrixes in BHb. The red- shift of characteristic peak leads to be conjecture that the arsenic of realgar conbined with the oxygen of BHb. The oxygen-BHb was deoxidated by realgar nanoparticles, and the surface binding induces conformation change of BHb from the high-affinity R state to the low-affinity T state. The fluorescence intensity of BHb is quenched by realgar nanoparticles when its concentration gradually increased. The analysis of Stern-Volmer equation revealed that the mechanism was a static quenching procedure. The order of the magnitude of binding constant k was 109 , obtained from the calculation of UV-Vis and fluorescence spectra.