Decorating rare-earth fluoride upconversion nanoparticles on AuNRs@Ag core-shell structure for NIR light-mediated photothermal therapy and bioimaging

Photothermal therapy(PTT)has presented its inherent application value in cancer treatment.Nevertheless,single-functional photothermal materials cannot meet the precise diagnosis and treatment of cance r.Therefo re,it is important to design a nanocomposite that has both high therapeutic efficiency and multimodal imaging capabilities.In our work,a new nanostructure of gold nanorods(AuNRs)with silver shells decorated by BaGdF5:Yb^(3+),Er^(3+)nanoparticle was synthesized by a simple way.The biostability of AuNRs is increased by coating with silver shells,and the AuNR@Ag nanoparticles can be used as excellent surface enhanced Raman scattering(SERS)probe.Moreover,the modification of BaGdF5:Yb^(3+),Er^(3+)nanoparticles provides the possibility of real-time optical imaging of the tumor area.Under the irradiation of NIR laser,the AuNR@Ag/BaGdF5:Yb^(3+),Er^(3+)nanocomposites(NCs)have strong upconversion emission and excellent photothermal conversion efficiency.Meanwhile,the NCs show low cytotoxicity and good biocompatibility in MTT cytotoxicity test.Moreover,the NCs are also exceptional contrast agents for CT imaging.For in vitro photothermal therapy test,NCs show excellent killing efficiency on tumor cells.Therefore,the multifaceted research of AuNR@Ag/BaGdF5:Yb^(3+),Er^(3+)multifunctional nanomaterials provides a break for high-efficiency tumor photothermal therapy and multimodal imaging.