Colloidal (Gd0.98Nd0.02)(2)O-3 nanothermometers operating in a cell culture medium within the first and second biological windows

authors	Debasu, ML; Oliveira, H; Rocha, J; Carlos, LD
nationality	International
journal	JOURNAL OF RARE EARTHS
author keywords	Gd2O3; Nd3+-doped nanoparticles; Luminescent nanothermometry; Thermal sensitivity; Cytotoxicity of nanoparticles; Rare earths
keywords	UP-CONVERSION; THERMAL SENSITIVITY; NANOPARTICLES; NANOCRYSTALS; THERMOMETRY; SIZE
abstract	Non-contact, self-referenced and near-infrared luminescent nanothermometers have been recognized as emerging tools in the fields of nanomedicine and nanotechnology due to their great capability of precise temperature readout at the nanoscale and real-time deep-tissue imaging. However, the development of multifunctional and biocompatible luminescent nanothermometers operating within the optically transparent biological windows with high thermal sensitivity (>2.0%/K) remains challenging. Here, we present (Gd0.98Nd0.02)(2)O-3 nanothermometers operated effectively within the first and second biological windows upon continuous-wave laser diode excitation at 808 nm. Ratiometric thermometric parameters are defined by the relative changes in the emission intensities originating from the two Stark components of the F-4(3/2) level (R-2 and R-1) to the I-4(9/2) (900-1000 nm), I-4(11/2) (1035-1155 nm) and I-4(13/2) (1300-1450 nm) multiplets. The thermometric parameters are evaluated for colloidal samples in a cell culture medium and powder samples, and the highest thermal sensitivity (2.18%/K at 298 K) is attained for the former in the first biological window (both the excitation and emission in the 800-965 nm range). The repeatability and temperature uncertainty are 99% and 1.2 K, respectively. The nanothermometers are biocompatible with human MNT-1 melanoma and HaCaT cells for 24 h of exposure and nanoparticle concentration up to 0.400 mg/mL, showing their potential for applications in nanomedicine, e.g., intracellular imaging and temperature mapping. (C) 2020 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.
publisher	ELSEVIER
issn	1002-0721
year published	2020
volume	38
issue	5
beginning page	483
ending page	491
digital object identifier (doi)	10.1016/j.jre.2019.12.011
web of science category	Chemistry, Applied
subject category	Chemistry
unique article identifier	WOS:000534541200005