Combining a pyclen framework with conjugated antenna for the design of europium and samarium luminescent bioprobes.

The first pyclen based ligand bearing two picolinate intra-ligand charge transfer transition antennae and one acetate arm organized in a dissymmetric manner was synthesized for Eu(iii) and Sm(iii) complexation. The europium complex presents an excellent brightness and biphotonic imaging of T24-cells has been performed using Eu(iii) and the less common Sm(iii) bioprobes.