Synthesis and properties of europium complexes derived fromcoumarin-derivatized azamacrocycles

Synthesis and properties of a series of new europium fluorescent probes based on azamacrocyclic compounds derivatized with coumarins as lanthanide sensitizers are described. Photophysical properties were investigated in water and standard human plasma. In the developed series, two compounds proved efficient for energy transfer from coumarin-centered to Eu3+-centered levels and are compatible with FRET experiments involving UV-LEDs excitation source. Some of the compounds exhibit interesting characteristics as wavelength-ratiometric pH sensors.