Designing of UCNPs@Bi@SiO2 Hybrid Theranostic Nanoplatforms for Simultaneous Multimodal Imaging and Photothermal Therapy.

Herein, a novel multifunctional nanoplatform was designed toward multimodality imaging and photothermal therapy (PTT). It was found that Bi nanoparticles could grow in situ on the surface of NaYF4:20%Yb,2%Er@NaYF4:40%Yb@NaGdF4 core-shell nanoparticles (labeled as UCNPs). In this structure, UCNPs were mainly employed as an upconversion luminescence (UCL) imaging agent, whereas the Bi nanoparticles worked as an effective CT imaging and photothermal agent. Importantly, a dense SiO2 shell was employed to protect the Bi nanoparticles from oxidation, and it also endowed the nanoplatform with excellent hydrophilic ability. The effective UCL/CT imaging and PTT performances were emphasized by a series of in vivo experiments, which suggest that the integrated nanoplatform with imaging and therapy functions shows great promise in the biomedical field.