Cationic Biphotonic Lanthanide Luminescent Bioprobes Based on Functionalized Cross-Bridged Cyclam Macrocycles

Chemphyschem. 2020 May 18;21(10):1036-1043. doi: 10.1002/cphc.202000085. Epub 2020 Apr 7.

Abstract

Cationic lanthanide complexes are generally able to spontaneously internalize into living cells. Following our previous works based on a diMe-cyclen framework, a second generation of cationic water-soluble lanthanide complexes based on a constrained cross-bridged cyclam macrocycle functionalized with donor-π-conjugated picolinate antennas was prepared with europium(III) and ytterbium(III). Their spectroscopic properties were thoroughly investigated in various solvents and rationalized with the help of DFT calculations. A significant improvement was observed in the case of the Eu3+ complex, while the Yb3+ analogue conserved photophysical properties in aqueous solvent. Two-photon (2P) microscopy imaging experiments on living T24 human cancer cells confirmed the spontaneous internalization of the probes and images with good signal-to-noise ratio were obtained in the classic NIR-to-visible configuration with the Eu3+ luminescent bioprobe and in the NIR-to-NIR with the Yb3+ one.

Keywords: Bioimaging; europium(III); luminescence; two-photon microscopy; ytterbium(III).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cations / chemistry
  • Cell Line, Tumor
  • Coordination Complexes / chemical synthesis
  • Coordination Complexes / chemistry*
  • Density Functional Theory
  • Humans
  • Lanthanoid Series Elements / chemistry*
  • Luminescent Agents / chemical synthesis
  • Luminescent Agents / chemistry*
  • Macrocyclic Compounds / chemical synthesis
  • Macrocyclic Compounds / chemistry*
  • Molecular Structure
  • Optical Imaging*
  • Photons*
  • Spectroscopy, Near-Infrared

Substances

  • Cations
  • Coordination Complexes
  • Lanthanoid Series Elements
  • Luminescent Agents
  • Macrocyclic Compounds