Abstract: | Nanoparticles (NPs) from diketonates of Al3+, Sc3+, In3+ and Ln3+ doped with dye molecules are synthesized. The appearance of sensitized fluorescence (cofluorescence) of dye molecules due to energy transfer from the ensemble of complexes forming NPs is revealed in aqueous solutions of these NPs. It is shown that the dye cofluorescence in NPs from Eu complexes occurs as a result of two distinct processes of energy transfer (ET) to dye molecules: from singlet levels of ligands and from Eu3+ ions. It is found that the efficiency of ET from Eu3+ ions to dyes in NPs from Eu(DBM)3phen is one order of magnitude higher than the efficiency of ET from S1-levels of ligands to dyes in NPs from Al complexes with the same ligands. It is shown that the excitation of dye molecules through ligands of NPs results in the enhancement of the intensity of their fluorescence by a factor of 1.5–2 orders of magnitude compared to the excitation of their own first band of absorption. |