Sub-10 nm Hexagonal Lanthanide-Doped NaLuF_4 Upconversion Nanocrystals for Sensitive Bioimaging in Vivo

摘要

By thermal decomposition in the presence only of oleylamine, sub-10 nm hexagonal NaLuF_4-based nanocrystals codoped with Gd~(3+), Yb~(3+), and Er~(3+) (or Tm~(3+)) have been successfully synthesized. Sub-10 nm β-NaLuF_4: 24 mol % Gd~(3+), 20 mol % Yb~(3+), 1 mol % Tm~(3+) nanocrystals display bright upconversion luminescence (UCL) with a quantum yield of 0.47 ± 0.06% under continuous-wave excitation at 980 nm. Furthermore, through the use of β-NaLuF_4: Gd~(3+),Yb~(3+),Tm~(3+) nanocrystals as a luminescent label, the detec tion limit of <50 nanocrystal-labeled cells was achieved for whole-body photoluminescent imaging of a small animal (mouse), and high-contrast UCL imaging of a whole-body black mouse with a penetration depth of ～2 cm was achieved.