Luminescent La2O2S:Eu3+ nanoparticles as non-contact optical temperature sensor in physiological temperature range

Pure hexagonal-phase europium doped lanthanum oxysulflde (La2O2S: Eu3+) nanoparticles have been successfully prepared by a wet chemical method. Transmission electron microscopy (TEM) results show that the as synthesized nanoparticles are monodisperse and uniform with the size of about 15 nm. Luminescence properties of the La2O2S: Eu3+ nanoparticles were investigated by measuring the emission spectra and fluorescence decay curves at various temperature. These nanoparticles display remarkable thermal sensitivity in terms of both fluorescence intensity and fluorescence lifetime over a temperature range of 15-60 degrees C, which make La2O2S: Eu3+ nanoparticles superb candidates for fluorescent sensing of physiological temperatures with miniaturized temperature sensor down to the nanoscale. (C) 2014 Elsevier B.V. All rights reserved.