Multifunctional nanoparticles based on the Nd3+/Yb3+ codoped NaYF4

Broadband near-infrared luminescence (NIR) from 720 to 950 nm, which is located in the biological window, has been successfully achieved from Nd3+/Yb3+ codoped hexagonal NaYF4 nanoparticles when excited by 980 nm diode laser. Using the fluorescence intensity ratio technique, the temperature sensing behavior of Nd3+ NIR emissions exhibits various advantages over other rare earth ion based nano-thermometers. The light-induced thermal loading for the 980 nm excited NaYF4: Nd3+/Yb3+ was also investigated. The results illustrate the multifunctionality of such fluoride nanoparticles, which could simultaneously act as the luminescent nanothermometers and nanoheaters and find potential application in photothermal therapy. (C) 2015 Optical Society of America