Luminescent biscarbene iridium(iii) complexes as living cell imaging reagents

Zhou, Yuyang; Jia, Junli; Li, Wanfei; Hao, Fei; Zhou, Ming

doi:10.1039/c3cc40845k

Cited by 68 publications

(48 citation statements)

References 43 publications

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“…Recently, this compound was synthesized in situ and used without isolation. 17 The 1 H NMR spectrum of the Ir dimer was rather complex and difficult to interpret, indicating the presence of geometrical isomers.…”

Section: Inorganic Chemistrymentioning

confidence: 99%

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Cationic Iridium(III) Complexes with Two Carbene-Based Cyclometalating Ligands: Cis Versus Trans Isomers

et al. 2015

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A series of cationic iridium(III) complexes with two carbene-based cyclometalating ligands and five different N^N bipyridine and 1,10-phenanthroline ancillary ligands is presented. For the first time--in the frame of a rarely studied class of bis(heteroleptic) iridium complexes with two carbene-based cyclometalating ligands--a pair of cis and trans isomers has been isolated. All complexes (trans-1-5 and cis-3) were characterized by (1)H NMR, (13)C NMR, (31)P NMR, and HRMS (ESI-TOF); in addition, crystal structures of cis-3 and trans-4 are reported and discussed. Cyclic voltammetric studies show that the whole series exhibits highly reversible oxidation and reduction processes, suggesting promising potential for optoelectronic applications. Ground-state DFT and TD-DFT calculations nicely predict the blue shift experimentally observed in the room-temperature absorption and emission spectra of cis-3, compared to the trans complexes. In CH3CN, cis-3 displays a 4-fold increase in photoluminescence quantum yield (PLQY) with respect to trans-3, as a consequence of drastically slower nonradiative rate constant. By contrast, at 77 K, the emission properties of all the compounds, including the cis isomer, are much more similar, with a pronounced hypsochromic shift for the trans complexes. A similar behavior is found in solid state (1% w/w poly(methyl methacrylate) matrix), with all complexes displaying PLQY of ∼70-80%, comparable emission lifetimes (τ ≈ 1.3 μs), and a remarkable rigidochromic shift. To rationalize the more pronounced nonradiative deactivation (and smaller PLQY) observed for photoexcited trans complexes, comparative temperature-dependent emission studies in the range of 77-450 K for cis-3 and trans-3 were made in propylene glycol, showing that solvation effects are primarily responsible for the observed behavior.

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Section: Inorganic Chemistrymentioning

confidence: 99%

“…The observed chemical shifts in the proton NMR spectra correspond well to those reported in literature. 17 [Ir(Ph-Im) 2 was degassed by six vacuum and backfill cycles. The mixture was heated to reflux overnight.…”

Section: ■ Experimental Proceduresmentioning

confidence: 99%

Cationic Iridium(III) Complexes with Two Carbene-Based Cyclometalating Ligands: Cis Versus Trans Isomers

et al. 2015

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“…[28] These complexes have been applied as fluorescence reagents for living cell imaging [29] and constructing a label-free G-quadruplex-based assay for hepatitis C virus NS3 helicase activity in aqueous solution. [30] Zhang and co-workers [31] employed a cyclometalated Iridium(III) complex [(ppy) 2 Ir(dcbpy)](PF 6 ) as an ECL labeling reagent to construct an ultrasensitive biosensor, which was successfully applied in cancer cell detection.…”

Section: Introductionmentioning

confidence: 99%

Cyclometalated Iridium‐Complex‐Based Label‐Free Supersandwich Electrogenerated Chemiluminescence Biosensor for the Detection of Micro‐RNA

et al. 2017

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The synthesis and characterization of compounds as electrogenerated chemiluminescence (ECL) reagents are crucial in fundamental research for ECL biosensors. In this work, a new cyclometalated iridium(III) complex, [(bt) 2 Ir(dmphen)](PF 6 ), was synthesized by using 2-phenylbenzothiazole (bt) as the C^N main ligand and 5,6-dimethyl-1,10-phenanthroline (dmphen) as the N^N ancillary ligand. The photophysical, electrochemical, and ECL properties of this complex were extensively studied in acetonitrile solvent and aqueous solution. This complex displayed yellow-green photoluminescence with a maximum wavelength at 522 nm, a reversible one-electron oxidation wave at E 1/2 = + 1.51 V (vs. SCE), and a reversible one-electron reduction wave at À1.29 V (vs. SCE). Typically, in the annihilation process, the ECL efficiency of this complex was 12 times higher than that of Ru(bpy) 3 2 + . More importantly, a highly sensitive ECL method for the determination of micro-RNA at the subpicomolar level was developed on basis of employing this complex as an ECL intercalator and signal amplification by using the supersandwich model. Compared with Ru(phen) 3 Cl 2 and [(bt) 2 Ir(dcbpy)](PF 6 ), this complex showed a relatively low background and the highest increased ratio as an ECL intercalator in the developed system. The increased ECL intensity was directly proportional to the concentration of the micro-RNA in the range of 0.1 to 10 pM, with a detection limit of 13 fM. The developed method can effectively discriminate target micro-RNA122 from two-base mismatched micro-RNA122. This work demonstrates that this cyclometalated iridium(III) complex is an effective alternative intercalator for ECL determination of the micro-RNA. It is expected that this complex will be extended to design various analytical platforms for the detection of diverse analytes such as DNA/RNA, DNAzyme/target, and aptamer/targets.

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“…For example, five iridium(III) carbene complexes 26-30 have been used to stain the cytoplasm of HeLa cells [23]. Cells treated with the cationic complexes 26 and 27 exhibit much more intense intracellular phosphorescence than those incubated with the neutral analogs 28-30, suggestive of preferential cellular uptake of cationic compounds.…”

Section: Neutral Iridium(iii) Complexesmentioning

confidence: 99%

Phosphorescent Iridium(III) Complexes for Bioimaging

Zhang

Liu

Zhao

et al. 2014

Luminescent and Photoactive Transition Metal Complexes as Biomolecular Probes and Cellular Reagents

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Phosphorescent iridium(III) complexes have received increasing attention in bioimaging applications owing to their advantageous photophysical properties and efficient internalization into live cells. In this chapter, we summarize the recent design of bioimaging reagents based on phosphorescent iridium(III) complexes. The utilizations of cationic, neutral, and zwitterionic phosphorescent iridium(III) complexes in bioimaging applications have been described first.Complexes showing aggregation-induced phosphorescence have also been included considering the absence of the commonly observed aggregation-caused quenching. Then we discuss the functionalization of iridium(III) complexes with biological substrates and reactive groups, which allows non-covalent and covalent interaction, respectively, with intracellular biomolecules. As the photophysical properties of iridium(III) complexes are very sensitive toward their surrounding ligands and microenvironment, the use of these complexes as intracellular sensors for gas molecules, ions, and amino acids has been summarized. Additionally, the incorporation of iridium(III) complexes into dendrimer, polymer, and nanoparticle systems providing attractive functionalities has been discussed. Furthermore, various strategies, including the use of near-infrared-emitting and two-photon excitable complexes, upconversion nanoparticles, and lifetime-based microscopy techniques, to enhance signal-to-noise ratios in bioimaging have been discussed. At last, the design of reagents for multi-mode imaging techniques involving phosphorescence and magnetic resonance imaging has been described.

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Luminescent biscarbene iridium(iii) complexes as living cell imaging reagents

Cited by 68 publications

References 43 publications

Cationic Iridium(III) Complexes with Two Carbene-Based Cyclometalating Ligands: Cis Versus Trans Isomers

Cationic Iridium(III) Complexes with Two Carbene-Based Cyclometalating Ligands: Cis Versus Trans Isomers

Cyclometalated Iridium‐Complex‐Based Label‐Free Supersandwich Electrogenerated Chemiluminescence Biosensor for the Detection of Micro‐RNA

Phosphorescent Iridium(III) Complexes for Bioimaging

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