Rational Design of Phosphorescent Chemodosimeter for Reaction‐Based One‐ and Two‐Photon and Time‐Resolved Luminescent Imaging of Biothiols in Living Cells

Abstract

A selective phosphorescent biothiols probe is synthesized based on Ir(III) complex 1, which has 2,2'-biquinoline as the N^N ligand for realizing the satisfied two-photon absorption cross-section and two-functionalized 2-phenylpyridine ligands with an α,β-unsaturated ketone moiety as the thiol reaction site. The one- and two-photon optical properties of 1 are investigated through UV-vis absorption spectrum and photoluminescence spectrum. This Ir(III) complex can act as an excellent one- and two-photon excited "OFF-ON" phosphorescent probe for biothiols based on the 1,4-addition of biothiol to α,β-unsaturated ketones. Moreover, one- and two-photon-induced luminescent imagings of biothiols in living cells are also realized. Furthermore, the experiments of time-resolved photoluminescence technique and fluorescence lifetime imaging microscopy demonstrate that 1 is able to detect biothiols in the presence of strong background fluorescence. In addition, probe 1 is adsorbed into the shell of mesoporous silica nanoparticles with core-shell structure to form a nanoprobe, which can realize the ratiometric detection of biothiols in absolute water solution and living cells based on two phosphorescent signals.

High-resolution in vivo optical imaging of stroke injury and repair

“…Probes were also developed for detecting small molecules such as NO (Dong et al, 2013; Yu et al, 2012), H + (pH probes) (Han and Burgess, 2010; Kim et al, 2013), singlet O 2 (Song et al, 2013; K. Xu et al, 2011), H 2 O 2 (Belousov et al, 2006; Guo et al, 2014), Cl - (Arosio and Ratto, 2014), large biomolecules such as matrix metalloproteinases (Vandenbroucke and Libert, 2014) and various biothiols (Xu et al, 2014), as well as complex cellular processes such as labeling dying cells with propidium iodide (Driscoll et al, 2011) or assessing the glutathione redox potential (Gutscher et al, 2008). …”

Phosphorescent Iridium(III) Complexes for Bioimaging

“…Two-photon excitation images of HeLa cells have been obtained under excitation at 680-800 nm. Another two-photon excitable iridium(III) complex 124 has been designed as an intracellular sensor for biothiols [90]. This complex contains two α,β-unsaturated ketone groups which undergo 1,4-addition reaction with Cys, giving the 124-Cys 2 analog.…”

Strong nonlinear optical phosphorescence from water-soluble polymer dots: Towards the application of two-photon bioimaging

“…With much longer lifetime of TES and larger Stokes shift, phosphorescence can more effectively reduce interference from excitation light, autofluorescence and self-quenching. Additionally, the phosphorescent metal complexes can be utilized not only as optical sensors for oxygen, but also as photosensitizers for photodynamic therapy [8,9]. Although there were many reported phosphorescent probes based on metal complexes, most of them were achieved through one-photon excitation [8,9].…”

“…Additionally, the phosphorescent metal complexes can be utilized not only as optical sensors for oxygen, but also as photosensitizers for photodynamic therapy [8,9]. Although there were many reported phosphorescent probes based on metal complexes, most of them were achieved through one-photon excitation [8,9]. In fact, heavy-metal complexes are also good candidates as nonlinear optical phosphorescent chromophores, whose TPA can be easily tuned by changing the metal centers or/and ligand structures through their synergistic role [10].…”