title: Development of a novel europium complex-based luminescent probe for time-gated luminescence imaging of hypochlorous acid in living samples.
abstract: Luminescent lanthanide complexes are key reagents used in the time-gated luminescence bioassay technique, but functional lanthanide complexes that can act as luminescent probes for specifically responding to analytes are very limited. In this work, we designed and synthesized a novel Eu3+complex-based luminescence probe for hypochlorous acid (HOCl), NPPTTA-Eu3+, by using terpyridine polyacid-Eu3+, dinitrophenyl, and hydrazine as luminophore, quencher and HOCl-recognizer moieties, respectively. In the absence of HOCl, the probe is non-luminescent due to the strong luminescence quenching of the dinitrophenyl group in the complex. However, upon reaction with HOCl, the dinitrophenyl moiety is rapidly cleaved from the probe, which affords a strongly luminescent Eu3+complex CPTTA-Eu3+, accompanied by a ∼900-fold luminescence enhancement with a long luminescence lifetime of 1.41 ms. This unique luminescence response of NPPTTA-Eu3+to HOCl allowed NPPTTA-Eu3+to be conveniently used as a probe for highly selective and sensitive detection of HOCl under the time-gated luminescence mode. In addition, by loading NPPTTA-Eu3+into RAW 264.7 macrophage cells and Daphnia magna, the generation of endogenous HOCl in RAW 264.7 cells and the uptake of exogenous HOCl by Daphnia magna were successfully imaged on a true-color time-gated luminescence microscope. The results demonstrated the practical applicability of NPPTTA-Eu3+as an efficient probe for time-gated luminescence imaging of HOCl in living cells and organisms.
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry, Dalian University of Technology, Dalian 116024, People's Republic of China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Liu
authors.forename: Lianying
authors.initials: L
authors.lastname: Guo
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Tang
authors.forename: Jingli
authors.initials: J
authors.lastname: Yuan
mesh_terms: D000818:Animals; D003621:Daphnia; D004136:Dinitrobenzenes / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry*; D006997:Hypochlorous Acid / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D051379:Mice; D011725:Pyridines / Q000737:chemistry*; D000067996:RAW 264.7 Cells
chemical_list: D004136:Dinitrobenzenes; D006834:Hydrazines; D049408:Luminescent Agents; D011725:Pyridines; D005063:Europium; D006997:Hypochlorous Acid