Structural and surface studies of luminescent Ca/Eu phosphate nanomaterials: From the bulk to surface features

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2022-09, Vol.217, p.112620-112620, Article 112620
• Main Authors: Ivanchenko, Pavlo, Escolano-Casado, Guillermo, Mino, Lorenzo, Dassi, Luca, Fernández-Sánchez, Jorge F., Martra, Gianmario, Gómez-Morales, Jaime
• Format: Article
• Language: English
• Subjects: Europium phosphate; Hydroxyapatites; Luminiscent nanomaterials; Surface studies
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2022.112620

Three luminescent Eu-containing phosphate materials (Ca-doped europium phosphate monohydrate, Eu-doped carbonated-apatite, and europium phosphate monohydrate) were prepared and analyzed on the level of bulk structure and surface properties and compared to the biomimetic non-luminescent counterpart hydroxyapatite. Europium-containing phosphate materials exhibited nanosized dimensions but different luminescence emissions and luminescence lifetimes depending on their crystalline structures (i.e., lanthanide phosphate or apatites) and chemical composition. The introduction of Eu in the crystal lattice leads to a notable decrease in the overall Lewis acidity of the surface cationic sites detected by CO probing. Further, the mixed Eu/Ca-containing materials surfaces were found to be very similar to the reference hydroxyapatite in terms of water adsorption energy, while the pure europium phosphate resulted to have the notably higher energy values of direct interaction of water molecules with the surface cations with no detected propagation of this effect towards water overlayers. [Display omitted] •Ca2+ co-precipitation with EuPO4 leads to the formation of a stable rhabdophane phase.•EuPO4 exhibits high energy in the formation of the first hydration layer.•Adding Eu3+ results in a decrease in the surface Lewis acidity of hydroxyapatites.•Host phosphatic matrix structure influences luminescence lifetime and RLI of Eu3+.