title: Core/shell-type nanorods of Tb3+-doped LaPO4, modified with amine groups, revealing reduced cytotoxicity.
abstract: A simple co-precipitation reaction between Ln3+cations (Ln = lanthanide) and phosphate ions in the presence of polyethylene glycol (PEG), including post-treatment under hydrothermal conditions, leads to the formation of Tb3+-doped LaPO4crystalline nanorods. The nanoparticles obtained can be successfully coated with amorphous and porous silica, forming core/shell-type nanorods. Both products reveal intensive green luminescence under UV lamp irradiation. The surface of the core/shell-type product can also be modified with -NH2groups via silylation procedure, using 3-aminopropyltriethoxysilane as a modifier. Powder X-ray diffraction, transmission electron microscopy, and scanning electron microscopy confirm the desired structure and needle-like shape of the products synthesized. Fourier transform infrared spectroscopy and specific surface area measurements by Brunauer-Emmett-Teller method reveal a successful surface modification with amine groups of the core/shell-type nanoparticles prepared. The nanomaterials synthesized exhibit green luminescence characteristic of Tb3+ions, as solid powders and aqueous colloids, examined by spectrofluorometry. The in vitro cytotoxicity studies reveal different degree toxicity of the products. LaPO4:Tb3+@SiO2@NH2exhibits the smallest toxicity against B16F0 mouse melanoma cancer cells and human skin microvascular endothelial cell lines, in contrast to the most toxic LaPO4:Tb3+@SiO2.
authors.affiliation: Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Runowski
authors.forename: Krystyna
authors.initials: K
authors.lastname: Dąbrowska
authors.forename: Tomasz
authors.initials: T
authors.lastname: Grzyb
authors.forename: Paulina
authors.initials: P
authors.lastname: Miernikiewicz
authors.forename: Stefan
authors.initials: S
authors.lastname: Lis
keywords: Amine groups –NH2; Core/shell nanorods; Cytotoxicity; Luminescence; Surface modification; Tb3+-doped phosphates