title: Mitochondria Targetable Time-Gated Luminescence Probe for Singlet Oxygen Based on a β-Diketonate-Europium Complex.
abstract: Singlet oxygen ((1)O2) plays a key role in the photodynamic therapy (PDT) technique of neoplastic diseases. In this work, by using a 9,10-dimethyl-2-anthryl-containing β-diketone, 1,1,1,2,2-pentafluoro-5-(9',10'-dimethyl-2'-anthryl)-3,5-pentanedione (Hpfdap), as a (1)O2-recognition ligand, a novel β-diketonate-europium(III) complex that can act as a luminescence probe for (1)O2, [Eu(pfdap)3(tpy)] (tpy = 2,2',2″-terpyridine), has been designed and synthesized for the time-gated luminescence detection of (1)O2 in living cells. The complex is weakly luminescent due to the quenching effect of 9,10-dimethyl-2-anthryl groups. After reaction with (1)O2, accompanied by the formation of endoperoxides of 9,10-dimethyl-2-anthryl groups, the luminescence quenching disappears, so that the long-lived luminescence of the europium(III) complex is switched on. The complex showed highly selective luminescence response to (1)O2 with a remarkable luminescence enhancement. Combined with the time-gated luminescence imaging technique, the complex was successfully used as a luminescent probe for the monitoring of the time-dependent generation of (1)O2 in 5-aminolevulinic acid (a PDT drug) loaded HepG2 cells during the photodynamic process. In addition, by coloading the complex and a mitochondrial indicator, Mito-Tracker Green, into HepG2 cells, the specific localization of [Eu(pfdap)3(tpy)] molecules in mitochondria of HepG2 cells was demonstrated by confocal fluorescence imaging measurements.
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry, Dalian University of Technology , Dalian 116024, People's Republic of China.
authors.forename: Jingyan
authors.initials: J
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry, Dalian University of Technology , Dalian 116024, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry, Dalian University of Technology , Dalian 116024, People's Republic of China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry, Dalian University of Technology , Dalian 116024, People's Republic of China.
authors.forename: Jingli
authors.initials: J
authors.lastname: Yuan
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005063:Europium / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D049449:Luminescence; D013058:Mass Spectrometry; D008928:Mitochondria / Q000378:metabolism*; D015335:Molecular Probes; D026082:Singlet Oxygen / Q000378:metabolism*
chemical_list: D007659:Ketones; D015335:Molecular Probes; D026082:Singlet Oxygen; D005063:Europium