Development And Application Of The Transition Metal Complexes-based Photoluminescent Probes For Nitric Oxide

Nitric oxide (NO) is a kind of highly unstable free radical molecules, with an isolated electron, making its chemical properties very reactive. In recent years, NO was found widely to exist in the tissues and it is one kind of endogenous signaling gasotransmitters. NO could be produced in cells and move to other cells and tissues, by interacting with bioactive molecules it could generate more highly active molecules at the same time. It plays an important biological role in the field of heart cerebrovascular, immune, nerve and urinary and reproductive systems. So the research of the nitric oxide has always been an interesting topic among the researches.In this work, by using2,2’-bipyridine (bpy) and1,10-phenanthroline (phen) as ligands, two highly sensitive and selective Ru (Ⅱ) complex-based phosphorescence probes,[Ru(bpy)3_n(DA-phen)n](PF6)2(n=1,2), have been designed and synthesized as photoluminescent (PL) and electrochemiluminescent (ECL) dual-signaling probes for the detection of nitric oxide at room temperature in aqueous and biological samples. The phosphorescence and the electrochemical luminescence intensities of the probes are very weak. After reacting with NO solution in the air, the triazole derivatives of the probes,[Ru(bpy)3-n(TA-phen)n](PF6)2(n=1,2), were yielded at room temperature, accompanied by a remarkable increase in the PL and ECL intensities with low detection limits and good linear relationships. In addition, the probes can be rapidly permeated through living cells and plant tissues for trapping the intracellular NO molecule, realizing the high sensitivity and selectivity of phosphorescence and the electrochemical luminescence signal detection of this small molecule in the complex biological samples. It not only provides a new detection means for biomedical and life science research in the determination of physiological active component, but also afford effective strategies and ideas which could be used for the development and application of electrochemical luminescence analysis technology and light-electric luminescence dual-signalling.At the same time, a highly sensitive and selective Ir (Ⅲ) complex-based phosphorescence probe,[Ir(ppy)2(An-bpy)](PF6), has been designed and synthesized for the detection of nitric oxide at room temperature by using2-phenyl pyridine (ppy) and1,10-phenanthroline (phen) as the ligands. The phosphorescence intensity of the probe is weak, however its phosphorescence intensity would be enhanced after the triazole compound,[Ir(ppy)2(TA-phen)](PF6), generated by reacting with NO. This probe has a lot of advantages, for example, good photophysical and chemical properties, high luminous efficiency and selectivity, emission in the visible region,which is available for sensitive phosphorescence detection of NO.