High-efficient fabrication of core-shell-shell structured SiO 2 @GdPO 4 :Tb@SiO 2 nanoparticles with improved luminescence

Abstract

SiO 2 @GdPO 4 :Tb@SiO 2 nanoparticles with core-shell-shell structure were successfully synthesized by a cheap silane coupling agent grafting method at room temperature. This method not only homogeneously coated rare-earth phosphate nanoparticles on the surface of silica spheres but also saved the use of rare-earth resources. The obtained nanoparticles consisted of SiO 2 core with a diameter of approximately 210 nm, GdPO 4 :Tb intermediate shell with thickness of approximately 7 nm, and SiO 2 outer shell with thickness of approximately 20 nm. This unique core-shell-shell structured nanoparticles exhibited strong luminescence properties compared with GdPO 4 :Tb nanoparticles. The core-shell-shell structured nanoparticles can effectively quench the intrinsic fluorescence of bovine serum albumin through a static quenching mode. The as-synthesized nanoparticles show great potential in biological cell imaging and cancer treatment.