Synthesis And Applications Of Ruthenium/Iridium Complexes-based Multifunction Luminescent Probes

Ruthenium(II)/iridium(III)complexes have excellent photophysical,photochemical and electrochemical properties,further more,they have good cell membrane permeability and biocompatibility.Therefore,ruthenium(II)/iridium(III)complexes can be designed as biomolecule probes with multiple signals.In this paper,two kinds of multifunctional luminescent probes were synthesized through modifying ruthenium(II)/iridium(III)complexes with specific recognition groups to apply in the detections of related molecules in vivo.Firstly,a mitochondrial-target luminescent probe Ir-Fc was designed and synthesized by conjugation of ferrocene quencher and the complex through a HOCl-sensitive hydrazine linker.The produced chemosensor,Ir-Fc,is weakly luminescent in both PL and ECL analysis due to the presence of photoinduced-electron-transfer(PET)process.The specific cleavage of ferrocenyl quencher from the Ir-Fc mediated by HOCl led to turn-on of Ir-Fc,so Ir-Fc was expected to be used for PL and ECL sensing of HOCl.The cleavage of ferrocenyl by HOCl was then confirmed by the electrochemical test.The results demonstrated the applicability of Ir-Fc as an effective chemosensor for imaging of HOCl generation in mitochondria of cells and liver injury in vivo,implying the potential of Ir-Fc for biomedical diagnosis and monitoring applications.In addition,two red-emitting transition-metal complexes,[Ru(bpy)2(DA-phen)](PF6)2 and [Ir(ppy)2(DA-phen)]PF6 were designed and synthesized as multisignal phosphorescent probes for the highly sensitive and selective detection of methylglyoxal(MGO).Both probes showed weak emissions because of the existence of an effective PET process,while their emissions could be remarkably enhanced upon the addition of MGO.The photophysical and electrochemical properties,as well as phosphorescent responses of the probes toward MGO,were examined.Furthermore,their applicability for visualizing intracellular and in vivo MGO was demonstrated,which indicated that the probes have low cytotoxicity and excellent application performance for biological imaging.MGO is an essential biomarker in the etiopathogenesis of several diseases,but the chemosensors for MGO detection were rarely reported.Therefore this work will provide a good idea for the future work.