DNA分子光开关是指在水溶液中不发光或微弱发光,加入DNA后光致发光强度大幅度增强的金属配合物.此类配合物在DNA结构探针、DNA错配的检测、DNA定量分析、分子逻辑门、DNA-蛋白质的键合标记及新型光电器件等方面具有非常重要的应用前景.自从Barton报道。首例DNA分子光开关Ru(bpy)2(dppz)^2+以来,对DNA分子光开关的研究不断深入,主要围绕对主配体dppz的修饰和中心离子的更换而扩展到多个体系.但对于新型的DNA分子光开关Ru(Ⅱ)配合物的报道较少.
A new ruthenium (Ⅱ) complex, [Ru (bpy) 2 bdpq] (ClO4) 2, where bpy = 2,2'-bipyridine, bdpq = 2-(benzoxazol-2-yl)-dipyrido [2,3-f: 2' ,3'-h] quinoxaline, was synthesized and characterized by IR, 1^H NMR, MALDI-TOF MS, and elemental analysis. The electronic absorption and emission spectral titrations with calf thymus DNA, steady-state emission quenching by [ Fe( CN)6 ]^4-, and viscosity measurements were carried out to study the binding of [ Ru (bpy) 2 bdpq ] (CIO4) 2 with the DNA. The results indicate that the Ru(Ⅱ) complex acts as a DNA intercalator with a binding constant of (1.9 +0. 1) ×10^6 L/mol at 50 mmol/ L NaCI, and can serve as a good "DNA molecular light switches" with a luminescence enhancement factor of 180.