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International audience; Multifunctionalized porous silicon nanoparticles (pSiNP) containing novel Ru(II) complex-photosensitizer, polyethylene glycol moiety, and mannose molecules as cancer targeting ligands, are constructed and showcased for application in near infrared (NIR) light-responsive photodynamic therapy (PDT) and imaging of cancer. Exposure to NIR light leads to twophoton excitation of the Ru(II)-complex which allows efficient simultaneous cancer-imaging and targeted PDT therapy with the functionalized biodegradable pSiNP nanocarriers.

Displaying a dual emission, a Phen-PENMe2 compound can be foreseen as a new model for fundamental studies. It is based on an excited state cumulene-type structure, involving orthogonal π orbital (OPICT). In contrast to the "Twisted Intramolecular Charge Transfer" (TICT) emission, the OPICT emissive state is planar. This new compound is also a potential candidate for local ratiometric probes of medium polarity (mixture of solvents and biological systems) and white emission.

A new cyclen derivative L, bearing a methyl-chromeno-pyridinylidene hydrazone moiety, was synthesized and studied in MeOH, as potential fluorescent “OFF-on-ON” sensors for Zn(II). Photocphysical properties of this ligand being PET regulated, L was only weakly emissive in the absence of metal ions (OFF). L fluorescence was increased modestly upon addition of one equivalent of Zn(II), and further increased upon addition of a second equivalent. Therefore, Zn:L behaved as a highly sensitive ON sensor for zinc. This efficiency was correlated to Zn(II) coordination via the hydrazone moiety of the fluorophore, producing an efficient CHelation-Enhanced Fluorescence (CHEF) effect. A complementary theoretical study carried out with DFT calculations further elucidated of the optical properties.

Two new fluorene derivatized 1,10-phenanthroline ligands and related tris-chelate Ru(II) or Zn(II) coordination complexes have been synthesised. The linear and nonlinear (two-photon induced fluorescence) photophysical measurements have contributed to highlight the possibility to tune the absorption spectral range and excited lifetime, depending on ligand substitution and nature of the metal. More significantly, the observation of two-photon absorption (TPA) associated with long-lived metal-to-ligand charge-transfer (MLCT) excited states in the Ru(II)-based chromophores, opens a wide range of applications in the near infrared.