Rare-earth-doped optical nanothermometer in visible and near-infrared regions

With the development of optical nanothermometry in biomedical sciences, it is urgent to develop near-infrared region (NIR) nanothermometers which could detect the temperature in deep tissue levels. In this study, NaYF₄:Yb,Er@NaGdF₄:Nd nanoparticles were successfully synthesized. The luminescence properties and the mechanism of formation of dumbbell morphology of NaYF₄:Yb,Er@NaGdF₄:Nd were investigated. As a novel optical nanothermometer, dumbbell-shaped NaYF₄:Yb,Er@NaGdF₄:Nd nanoparticles exhibited high sensitivity in the visible and NIR regions. These data seem to be promising in terms of expanding the optical detection range of non-contact fluorescence temperature sensors and satisfy the requirements for temperature detection in various biological tissues.