二(2,3-二氨基吩嗪)合铜配合物的合成及与DNA相互作用的电化学和荧光光谱研究

Synthesis,Characterization of 2,3-Diaminophenazine Copper Complex and Electrochemical Studies on Its DNA-binding Properties

溶剂热法合成了二(2,3-二氨基吩嗪)合铜配合物[Cu(DAP)2]2+,并用元素分析法和红外光谱法对其结构进行了表征。在pH=6.5的三羟甲基氨基甲烷-盐酸(Tris-HCl)缓冲溶液中,采用电化学方法及荧光光谱法研究了该配合物与DNA的相互作用。循环伏安实验表明,配合物在-0.04 V和-0.13 V处有一对氧化还原峰。加入双链DNA(dsDNA)或单链DNA(ssDNA)后,氧化还原峰电流明显降低且峰电位负移,表明二者之间可能主要存在静电作用,但铜配合物与dsDNA的相互作用强于与ssDNA的相互作用,可用于识别dsDNA和ssDNA。通过dsDNA加入前后峰电流的变化,计算得出配合物与dsDNA结合位点n=2.5,结合常数K=4.07×104L.mol-1。在荧光光谱图上,加入DNA后配合物的荧光强度有较大降低,产生明显的减色效应,验证了二者之间的静电作用。

A novel copper complex, [ Cu （DAP）2 ] Cl2 （DAP= 2,3-diaminophenazine）, was solvothermally synthesized and characterized by FT-IR and elemental analysis. The binding properties of the complex were studied by electrochemical and fluorescence methods. The results of the cyclic voltammetry showed that the copper complex had a pair of redox peaks with the oxidation potential and the reduction potential at -0.04 V and -0. 13 V, respectively. After the dsDNA or ssDNA were added, the peak currents declined with the peak potential shifting negatively. This suggested that the electrostatic interactions existed between the complex and dsDNA or ssDNA, which was also proved by the fluorescence analysis. The copper complex more strongly interacted with dsDNA than with ssDNA, by which dsDNA and ssDNA could be distinguished. The intrinsic binding constant and binding site size of the complex to dsDNA were 4.07 × 10^4 L · mol^-1 and 2.5, respectively.