Eu3+ and Tb3+ complexes based on an organo-alkoxysilane derived from 4-azido dipicolinic acid by ''click chemistry'' were coated onto silica nanoparticles previously prepared by the water in oil emulsion method. Structural and optical properties of the resulting luminescent core-shell monodisperse (30 nm) nanohybrids were fully characterized by infrared and Raman spectroscopies as well as by electron microscopy. Fluorescence spectroscopy evidenced that an efficient ligand-to-Ln3+ energy transfer-- both in the mono- and biphotonic modes--occurs. Furthermore, surface modification by amino groups was realized, paving the way for nanotags of biological interest.