Multifunctional Ag@NaGdF4:Yb3+, Er3+ core-shell nanocomposites for dual-mode imaging and photothermal therapy

摘要： Multifunctional core-shell nanostructure, which can be applied on bio-imaging and photothermal therapy (PTT), has attracted tremendous interest in recent years. Here, Ag@NaGdF4:Yb3+, Er3+ core-shell nanostructure incorporating luminescent, magnetic and photothermal conversion properties was prepared via a simple method. The as-prepared nanocomposites (NCs) exhibit uniform core-shell sphere morphology, green up-conversion luminescence (UCL), good paramagnetic and photothermal conversion behaviors. The luminescence resonance energy transfer (LRET) between Ag nanoparticles (NPs) and NaGdF4:Yb3+, Er3+ NPs were researched. The cytotoxicity test on HeLa cells using methyl thiazolyltetrazolium (MTT) assay shows good biocompatibility of the core-shell NCs. Moreover, in vitro computed tomography (CT) and UCL imaging studies and in vitro PTT of living assay suggest that the core-shell NCs can be used as theranostic nanoagents for dual-mode imaging guided PTT for tumor.