This doctoral thesis deals with the design and evaluation of fluorogenic probes for the detection of enzymatic activities in biological contexts of interest.

The development of stable fluorogenic probes incorporating ELF-97 is one of the research themes actively pursued by our team. The successful development of peptidases and glycosidases probes have opened many perspectives. A first chapter will be dedicated to the diversification of these probes, firstly by the variation of substrates for the detection of new glycosidases, then by the development of an innovative spacer in the context of cell senescence. In particular, a probe for the detection of β-galactosidase in acidic medium has been synthesized and tested.

In parallel, work has focused on a new generation of probes targeting an enzyme family with strong scientific and societal interest: β-lactamases. The synthesis and the preliminary biological evaluation of a first model probe demonstrated the effectiveness of this new molecular architecture. This probe subsequently led to the development of first imaging results as part of an active collaboration with a Japanese research team.

Finally, a last part will be devoted to a project whose objective is not recent in the team: the development of alternatives to the ELF-97 presenting a shifted emission towards the red or the near infrared. For this purpose, the synthesis of new fluorophores, their physicochemical characterizations and incorporation tests in responding devices have been carried out. Several candidates have proved to have high potential for two main reasons: strongly red-shifted emission or high insolubility. They could eventually allow the adaptation of the technology to an in vivo use, the ultimate goal of the technology in the context of molecular imaging.