abstract
Temperature measurements ranging from a few degrees to a few hundreds of Kelvin are of great interest in the fields of nanomedicine and nanotechnology. Here, we report a new ratiometric luminescent thermometer using thermally excited state absorption of the Eu3+ ion. The thermometer is based on the simple Eu3+ energy level structure and can operate between 180 and 323 K with a relative sensitivity ranging from 0.7 to 1.7% K-1. The thermometric parameter is defined as the ratio between the emission intensities of the D-5(0) -> F-7(4) transition when the D-5(0) emitting level is excited through the F-7(2) (physiological range) or F-7(1) (down to 180 K) level. Nano and microcrystals of Y2O3:Eu3+ were chosen as a proof of concept of the operational principles in which both excitation and detection are within the first biological transparent window. A novel and of paramount importance aspect is that the calibration factor can be calculated from the Eu3+ emission spectrum avoiding the need for new calibration procedures whenever the thermometer operates in different media.
keywords
UPCONVERTING NANOPARTICLES; LUMINESCENT NANOTHERMOMETERS; FLUORESCENT NANOTHERMOMETERS; TEMPERATURE-MEASUREMENTS; ENERGY-TRANSFER; LIVING CELLS; NANOSCALE; SENSORS; EMISSION
subject category
Chemistry; Science & Technology - Other Topics; Materials Science; Physics
authors
Souza, AS; Nunes, LAO; Silva, IGN; Oliveira, FAM; da Luz, LL; Brito, HF; Felinto, MCFC; Ferreira, RAS; Junior, SA; Carlos, LD; Malta, OL
our authors
Luís Carlos
Full professor
Maria Rute de Amorim e Sá Ferreira André
Full professoracknowledgements
This work was carried out in the scope of the project CICECO - Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and, where applicable, co-financed by FEDER under the PT2020 Partnership Agreement. LDC acknowledges CAPES and CNPq (Brazil) for a Pesquisador Visitante Especial grant (313778/2013-2) within the Science without Borders programme.