title: Benefits of Silica Core-Shell Structures on the Temperature Sensing Properties of Er,Yb:GdVO4 Up-Conversion Nanoparticles.
abstract: We studied the temperature-dependent luminescence of GdVO4 nanoparticles co-doped with Er(3+) (1 mol %) and Yb(3+) (20 mol %) and determined their thermal sensing properties through the fluorescence intensity ratio (FIR) technique. We also analyzed how a silica coating, in a core-shell structure, affects the temperature sensing properties of this material. Spectra were recorded in the range of biological temperatures (298-343 K). The absolute sensitivity for temperature determination calculated for the core-shell nanoparticles is double the one calculated for bare nanoparticles, achieving a thermal resolution of 0.4 K. Moreover, silica-coated nanoparticles show good dispersibility in different solvents, such as water, DMSO, and methanol. Also, they show good luminescence stability without interactions with solvent molecules. Furthermore, we also observed that the silica coating shell prevents progressive heating of the nanoparticles during prolonged excitation periods with the 980 nm laser, preventing effects on their thermometric applications.
authors.affiliation: Physics and Crystallography of Materials and Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV) , Marcel·lí Domingo 1, Tarragona 43007, Spain.
authors.forename: Oleksandr A
authors.initials: OA
authors.lastname: Savchuk
authors.affiliation: Physics and Crystallography of Materials and Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV) , Marcel·lí Domingo 1, Tarragona 43007, Spain.
authors.forename: Joan J
authors.initials: JJ
authors.lastname: Carvajal
authors.affiliation: Instituto de Ciencia de Materiales de Madrid , c/Sor Juana Inés de la Cruz, Cantoblanco, Madrid 28049, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Cascales
authors.affiliation: Physics and Crystallography of Materials and Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV) , Marcel·lí Domingo 1, Tarragona 43007, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Aguiló
authors.affiliation: Physics and Crystallography of Materials and Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV) , Marcel·lí Domingo 1, Tarragona 43007, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Díaz
keywords: core−shell; luminescence; nanosensors; thermometry; up-conversion