Gold decorated NaYF4:Yb,Er/NaYF4/silica (core/shell/shell) upconversion nanoparticles for photothermal destruction of BE(2)-C neuroblastoma cells

Gold decorated NaYF4:Yb,Er/NaYF4/silica (core/shell/shell) upconversion (UC) nanoparticles (similar to 70-80 nm) were synthesized using tetraethyl orthosilicate and chloroauric acid in a one-step reverse microemulsion method. Gold nanoparticles (similar to 6 nm) were deposited on the surface of silica shell of these core/shell/shell nanoparticles. The total upconversion emission intensity (green, red, and blue) of the core/shell/shell nanoparticles decreased by similar to 31% after Au was deposited on the surface of silica shell. The upconverted green light was coupled with the surface plasmon of Au leading to rapid heat conversion. These UC/silica/Au nanoparticles were very efficient to destroy BE(2)-C cancer cells and showed strong potential in photothermal therapy.