中文摘要：

通过氯化钴、乙二醛和第五代树状高分子反应合成了金属钴树状高分子配合物。并以亚甲基蓝为荧光探针，通过紫外可见光谱、荧光光谱和同步荧光方法研究了金属钴树状高分子配合物与鲱鱼精DNA（hsDNA）的相互作用。结果显示，此配合物与hsDNA作用时，其紫外吸收产生明显增色效应，荧光强度增强。NaCl不同程度抑制金属钴树状高分子与hsDNA的结合。配合物也以竞争方式抑制亚甲基蓝与hsDNA作用，而亚甲基蓝可以插入金属钴树状高分子配合物的内部。这些结果证明，配合物主要通过与hsDNA链上带负电荷的磷酸基静电相吸形式结合而堆积在双螺旋hsDNA分子表面，减弱了结合位点附近亚甲基蓝分子与hsDNA的静电作用，而钠离子中和了hsDNA上磷酸基团上的负电荷，削弱了该配合物与hsDNA的静电结合。

英文摘要：

Cobalt（ Ⅱ ） polyamidomine dendrimer was prepared by the reaction of cobalt chloride, glyoxal and polyamidomine dendrimer of 5.0 generation. The interaction of cobalt （ Ⅱ ） polyamidomine dendrimer complex with herring sperm （hsDNA） was carried out using methylene blue （MB） as the probe molecule by absorption and fluorescence spectroscopy and synchronous fluorescence spectroscopy. The results showed that the intensity of absorption peaks and fluorescence peaks increased when the complex interacted with hsDNA. The effect of sodium chloride showed that sodium ion can significantly constrain the interaction of cobalt（ Ⅱ） polyamidomine dendrimer with hsDNA. The curves indicated the competitive inhibition of MB binding to hsDNA in the presence of cobalt （ Ⅱ ） polyamidomine dendrimer complexes, also MB could insert into interior of cobalt （Ⅱ ） polyamidomine dendrimer complexes. The results suggested that the complex mainly interacted with negatively charged phosphate moieties on hsDNA through electrostatic attraction and stacked on the surface of double stranded hsDNA, which may reduce the binding affinity of MB to hsDNA in the surrounding site. It was indicated that sodium ion might neutralize the negatively charged phosphate backbone of hsDNA, and then weaken the electrostatic attraction between complexes and hsDNA.