Crystallization, Luminescence and Cytocompatibility of Hexagonal Calcium Doped Terbium Phosphate Hydrate Nanoparticles Gómez Morales, Jaime Fernández Penas, Raquel Romero Castillo, Ismael Verdugo Escamilla, Cristóbal Choquesillo Lazarte, Duane Fernández Sánchez, Jorge Fernando Terbiumphosphates Calciumdoped Citrate Nanoparticles Luminescence Cytocompatibility Luminescent lanthanide-containing biocompatible nanosystems represent promising candidates as nanoplatforms for bioimaging applications. Herein, citrate-functionalized calcium-doped terbium phosphate hydrate nanophosphors of the rhabdophane type were prepared at different synthesis times and different Ca2+/Tb3+ ratios by a bioinspired crystallization method consisting of thermal decomplexing of Ca2+/Tb3+/citrate/phosphate/carbonate solutions. Nanoparticles were characterized by XRD, TEM, SEM, HR-TEM, FTIR, Raman, Thermogravimetry, inductively coupled plasma spectroscopy, thermoanalysis, dynamic light scattering, electrophoretic mobility, and fluorescence spectroscopy. They displayed ill-defined isometric morphologies with sizes 50 nm, hydration number n ~ 0.9, tailored Ca2+ content (0.42–8.11 wt%), and long luminescent lifetimes (800–2600 s). Their relative luminescence intensities in solid state are neither affected by Ca2+, citrate content, nor by maturation time for Ca2+ doping concentration in solution below 0.07 M Ca2+. Only at this doping concentration does the maturation time strongly affect this property, decreasing it. In aqueous suspensions, neither pH nor ionic strength nor temperature affect their luminescence properties. All the nanoparticles displayed high cytocompatibility on two human carcinoma cell lines and cell viability correlated positively with the amount of doping Ca2+. Thus, these nanocrystals represent promising new luminescent nanoprobes for potential biomedical applications and, if coupled with targeting and therapeutic moieties, they could be effective tools for theranostics. 2021-04-09T08:19:05Z 2021-04-09T08:19:05Z 2021-01-27 journal article Gómez-Morales, J.; Fernández-Penas, R.; Romero-Castillo, I.; Verdugo-Escamilla, C.; Choquesillo-Lazarte, D.; D’Urso, A.; Prat, M.; Fernández-Sánchez, J.F. Crystallization, Luminescence and Cytocompatibility of Hexagonal Calcium Doped Terbium Phosphate Hydrate Nanoparticles. Nanomaterials 2021, 11, 322. https://doi.org/ 10.3390/nano11020322 http://hdl.handle.net/10481/67870 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Mdpi