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

• DOI: 10.26434/chemrxiv.11591835.v1
• Publication Date: 2020-01-22T09:07:22Z
• Authors: Jonathan Mendy; Amandine Roux; Jean-Christophe M...; Alain Duperray; Alexei Grichine; Yannick Guyot; Sophie Brasselet; François Riobé; Chantal Andraud; Boris Le Guennic; Véronique Patinec; Raphael Tripier; Maryline Beyler; Olivier MAURY; Anh Thy Bui; Damien Curton

Cationic lanthanide complexes are generally able to spontaneously internalize into living cells. Following our previous works based on diMe-cyclen framework, a second generation of cationic water-soluble lanthanide complexes based on a constrained cross-bridged cyclam macrocycle functionalized with donor-p-conjugated picolinate antennas has been 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 is observed in the case of the Eu3+ complex, while the Yb3+ analogous conserve an excellent brightness 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 have been obtained in the classical NIR-to-visible configuration with Eu3+ luminescent bioprobe and in the NIR-to-NIR with the Yb3+ one.