Study On RuIr And OsIr Complexes For Nucleolus Light-up In Living Cells

The nucleolus of cell is the most prominent component existed in eukaryotic cell, which participat many key process in the cells including the synthesis of rRNA assembly ribosomal, participation of metabolism of RNA (besides rRNA) and regulation of cellular function. To observe the nucleolus of cell, fluorescence imaging exhibits the advantages of fast response, high sensitivity and easily applied of the instrument, which has attracted much attention of researchers. At present, SYTO RNA-Select, a green fluorescent cyanine cellular stain, is the only commercially available nucleolar stain, however, this organic dye emits at a single wavelength, and suffers from the drawbacks of photobleaching; moreover, its structure has not yet been published.To solve these problems, we synthesized a novel heterodinuclear ruthenium and iridium complex [Ru(bpy)3-(CH2)10-Ir(F2ppy)2]3+(RuIr) which have been developed as a dual luminescence agent for the imaging of living cells. The results have indicated that RuIr, in contrast to dimetallic complexes [Ru(bpy)3-(CH2)10-Ru(bpy)3]4+(RuRu) and [Ir(F2ppy)2-(CH2)10-Ir(F2ppy)2]2+(IrIr), without conjugation with a cell-penetrating molecular transporter, can rapidly and selectively light-up the nucleolus of living cells. More importantly, in contrast to the commercial "SYTO RNA-Select", complex RuIr exhibits dual luminescence (523nm,615nm), pronounced photostability and long emission lifetimes. The results have indicated that RuIr penetrate into the cell and lights up the nucleolus through interaction of RuIr with RNA, which induce a luminescence enhancement.To continuing our research in this route, a heterodinuclear near-infrared metal complex [Os(bpy)3-(CH2)10-Ir(F2ppy)2]3+(OsIr) was designed and synthesized. The results have indicated that in contrast to monometallic complexes [Os(bpy)3]2+(Os) and [Ir(F2ppy)2]+(Ir), this metal complex can rapidly and selectively light-up the nucleolus of living cells in2h. Compared with the commercial "SYTO RNA-Select", complex Osir exhibits dual luminescence (534nm,721nm), near-infrared luminescence and long emission lifetimes. The results have indicated that OsIr penetrate into the cell and lights up the nucleolus through interaction of Osir with both proteins and RNA, which induce a luminescence enhancement. These dual luminescence metal compelexes can perform cell imaging with dual channel, which suggest them to be a kind of potential nucelar probe, such novel heterodinuclear probes may also extend the arsenal of currently available fluorescent stains for novel nucelar probe.