Upconverting Nanophosphors: Preparation Strategies for highly colloidal Stable Particles; International Caparica Congress on Nanoparticles, Nanomaterials and Applications 2016

Neodymium containing upconverting nanophosphors (UCNPs)[1] Photon-upconverting nanoparticles (UCNPs) can be excited by near-infrared light and emit visible light(anti-Stokes emission) which prevents autofluorescence and over-heating effect of biological tissues. Due to their unique properties lanthanide-doped inorganic nanoparticles are very appealing particularly in bioimaging. Despite the fast progress in lanthanide-doped upconversion nanoparticles (UCNPs), the preparation of ultrasmall, monodisperse and hydrophilic UCNPs that display intense luminescence is still a challenging issue. Only a few examples of ultrasmall and hydrophilic UCNPs have been reported. [2-4] Information about biodistribution, pharmacokinetics and formation of protein corona is still missing for ultrasmall UCNPs. Therefore the aim of this project is to elaborate and to comprehensively characterize sub-10nm hydrophilic UCNPs. The luminescence properties will be tuned by varying the dopants and relative proportions as well as the fabrication of core-shell particles.
The size and shape of the particles will be influenced by controlling the reaction time and temperature course. To render them watersoluble, a ligand-exchange strategy will be used to replace the oleylamine surface groups by stabilization agents such as PEG-phosphates, O-phospho-L-serine, alendronic, zolendronic and risedronic acid.