DNA调制多吡啶钌(Ⅱ)配合物在ITO上的电化学及光致发光性能研究

Electrochemical and Photo-Luminescent Properties Modulated by DNA for Polypyridyl Ruthenium(Ⅱ) Complexes

本文应用伏安法、荧光光谱和荧光显微镜研究了多吡啶钌髤配合物[Ru(bpy)3]2+(Ru1)、[Ru(bpy)2phen]2+(Ru2)和[Ru(bpy)2tatp]2+(Ru3)(bpy=2,2′-联吡啶,phen=1,10-邻菲咯啉,tatp=1,4,8,9-四氮三联苯)在ITO上的电化学行为、光致发光性能及DNA在其中的调制作用。结果表明,Ru1、Ru2、Ru3分别在1.020、1.026、1.081V条件电位下在ITO电极上呈现出清晰的扩散控制波,随着连续伏安扫描次数的增加,较负电位下逐渐呈现出明显的吸附控制波。DNA的加入,尽管减小了这3种配合物在缓冲溶液中的扩散系数,但能促进其在ITO上的吸附组装。不管有无DNA存在,这3种钌髤配合物的组装强度均为Ru3>Ru2>Ru1。此外,在450nm波长光激发下,在ITO上的Ru1、Ru2、Ru3分别在576、588、610nm波长下呈现明显的发射峰,其量子产率按Ru1、Ru2、Ru3顺序增强。DNA的加入增大了Ru2和Ru3的发光强度和量子产率。该研究为具有氧化还原和光致发光活性生物分子器件的构筑提供一种新的思路。

The electrochemical and photo-luminescent properties of [Ru（bpy）3]2＋（Ru1）,[Ru（bpy）2phen]2＋（Ru2）and [Ru（bpy）2tatp]2 ＋（Ru3）（where bpy =2,2＇-bipyridine,phen =1,10-phenanthroline and tatp =1,4,8,9-tetra-azatriphenylene） on an ITO electrode in the absence and presence of DNA have been investigated by voltammetry,fluorescence spectroscopy and fluorescence microscopic imaging.It is found that cyclic voltammograms of the ruthenium（Ⅱ）complexes including Ru1,Ru2 and Ru3 distinctly exhibit a diffusion-controlled wave at the formal potentials of 1.020,1.026 and 1.081 V on the ITO electrode,respectively.With increasing voltammteric sweeping cycles,an adsorption-controlled wave gradually appears at a more negative potential than the diffusion-controlled wave.The presence of DNA decreases the diffusion coefficient of the three complexes in buffer solution and however their adsorbed assembly on the ITO electrode is enhanced.It is demonstrated that the adsorbed-assembly intensity in both the absence and presence of DNA conforms to the following order：Ru3Ru2Ru1.In addition,the emission spectra of Ru1,Ru2 and Ru3 immobilized on the ITO surface obviously show a luminescence peak at 576,588 and 610 nm under the excitation of 450 nm light source,respectively.The quantum yield of the three ruthenium complexes shows the following order：Ru3Ru2Ru1.The presence of DNA increases the luminescence intensity and quantum yield of Ru2 and Ru3.These results provide a novel way for better fabricating redox-luminescence biomolecule devices.