Liu Yao, Chouai Abdellatif, Degtyareva Natalya N, Lutterman Daniel A, Dunbar Kim R, Turro Claudia
Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA.
J Am Chem Soc. 2005 Aug 10;127(31):10796-7. doi: 10.1021/ja052648n.
The emission of the DNA light-switch complex [Ru(bpy)2(tpphz)]2+ (bpy = 2,2'-bipyridine, tpphz = tetrapyrido[3,2-a:2',3'-c:3' ',2' '-h:2' '',3' ''-j]phenazine) can be reversibly turned ON and OFF over several cycles. The tpphz and taptp (taptp = 4,5,9,18-tetraazaphenanthreno[9,10-b] triphenylene) ligands in [Ru(bpy)2(tpphz)]2+ and [Ru(bpy)2(taptp)]2+, respectively, intercalate between the DNA bases, and a 50-fold increase in emission intensity of [Ru(bpy)2(tpphz)]2+ is observed upon DNA intercalation. The [Ru(bpy)2(tpphz)]2+ DNA light switch can be turned OFF statically in the presence of Co2+, Ni2+, and Zn2+, and the emission can be fully restored by the addition of EDTA. Cycling of the DNA light switch OFF and ON can be accomplished through the successive introduction of Co2+ and EDTA, respectively, to solutions of DNA-bound [Ru(bpy)2(tpphz)]2+. Owing to the absence of additional coordination sites, the emission of DNA-intercalated [Ru(bpy)2(taptp)]2+ is not quenched by transition metal ions in solution. To our knowledge, this work presents the first example of a reversible DNA light switch.
DNA光开关复合物[Ru(bpy)₂(tpphz)]²⁺（bpy = 2,2'-联吡啶，tpphz = 四吡啶并[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]菲嗪）的发射可以在几个循环中可逆地开启和关闭。[Ru(bpy)₂(tpphz)]²⁺和[Ru(bpy)₂(taptp)]²⁺（taptp = 4,5,9,18-四氮杂菲并[9,10-b]三亚苯基）中的tpphz和taptp配体分别插入DNA碱基之间，并且在DNA插入时观察到[Ru(bpy)₂(tpphz)]²⁺的发射强度增加了50倍。在Co²⁺、Ni²⁺和Zn²⁺存在下，[Ru(bpy)₂(tpphz)]²⁺ DNA光开关可以静态关闭，并且通过添加EDTA可以完全恢复发射。DNA光开关的关闭和开启循环可以分别通过向与DNA结合的[Ru(bpy)₂(tpphz)]²⁺溶液中连续引入Co²⁺和EDTA来实现。由于没有额外的配位位点，DNA插入的[Ru(bpy)₂(taptp)]²⁺的发射不会被溶液中的过渡金属离子淬灭。据我们所知，这项工作展示了可逆DNA光开关的首个实例。
