A lysosome targetable luminescent bioprobe based on a europium β-diketonate complex for cellular imaging applications

Dalton Trans. 2016 Nov 22;45(46):18719-18729. doi: 10.1039/c6dt03833f.

Abstract

Herein, we report a novel lysosome targetable luminescent bioprobe derived from a europium coordination compound, namely Eu(pfphOCH3IN)3(DDXPO) 4 [where HpfphOCH3IN = 4,4,5,5,5-pentafluoro-3-hydroxy-1-(1-(4-methoxyphenyl)-1H-indol-3-yl)pent-2-en-1-one and DDXPO = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene oxide]. Notably, the newly designed europium complex exhibits significant quantum yield (Φoverall = 25 ± 3%) and 5D0 excited state lifetime (τ = 398 ± 3 μs) values under physiological pH (7.2) conditions when excited at 405 nm. Hence the developed europium complex has been evaluated for live cell imaging applications using mouse pre-adipocyte cell lines (3T3L1). Colocalization studies of the designed bio-probe with commercial Lysosome-GFP in 3T3L1 cells demonstrated the specific localization of the probe in the lysosome with a high colocalization coefficient (A = 0.83). Most importantly, the developed bioprobe exhibits good cell permeability, photostability and non-cytotoxicity.

MeSH terms

  • 3T3-L1 Cells
  • Animals
  • Coordination Complexes / analysis
  • Coordination Complexes / chemistry*
  • Europium / analysis
  • Europium / chemistry*
  • Halogenation
  • Indoles / analysis
  • Indoles / chemistry
  • Ligands
  • Luminescent Agents / analysis
  • Luminescent Agents / chemistry*
  • Lysosomes / ultrastructure*
  • Mice
  • Microscopy, Confocal / methods
  • Optical Imaging / methods*
  • Xanthenes / analysis
  • Xanthenes / chemistry

Substances

  • 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene oxide
  • Coordination Complexes
  • Indoles
  • Ligands
  • Luminescent Agents
  • Xanthenes
  • Europium