Luminescent sol-gel-derived micro and nanoparticles

This paper presents a short review of the results obtained by the authors in the field of the sol–gel-derived glass nanoparticles activated with lanthanides ions. The attention is focused on the systems that are particularly interesting for photonic structures and bioapplications. We discuss how the sol–gel technology allows to prepare different kind of active nanoparticles and how is possible to use them in specific applications. Some examples showing fabrication techniques of spherical micro- and nanoparticles are given, including preparation of rare-earth-doped silica and silica-calcia glass. The proper structures are mentioned to tailor the optical and spectroscopic properties of microresonators. Glass-ceramics systems are also reminded where nanocrystalline particles are derived. Fabrication and spectroscopic assessment of rare earth doped HfO 2 and SnO 2 nanoparticles are presented as well. Finally, it is discussed how bioactive properties of SiO 2 – CaO nanoparticles can be used in medicine, for example in tracking using their luminescent properties.