Novel and High-Sensitive Primary and Self-Referencing Thermometers Based on the Excitation Spectra of Lanthanide Ions


Remote sensing through ratiometric luminescence thermometry based on trivalent lanthanide ions (Ln(III)) has lately become a promising technique due to its numerous applications. Most available Ln(III)-based luminescent thermometers require a calibration process with a reference thermal probe (secondary thermometers) and recurrent calibrations are mandatory, particularly when the thermometers are used in different media. This is sometimes impractical and a medium-independent calibration relation is postulated, which is potentially inaccurate. Thus, the determination of the temperature based on well-grounded physical principles by primary thermometers is the only way to overcome these challenges. Despite being considered one of the most important developments in luminescence thermometry, primary luminescent thermometers are scarce. Primary thermometers requiring calibration are proposed, implemented, and validated at one known temperature (primary-T), which are also self-referencing, employing ratiometric data from the excitation spectrum of Ln(III). By combining with the emission spectrum, thermometers not requiring calibration (primary-S) are devised. An Eu(III)-beta-diketonate complex is used as a proof-of-concept, but the approach is universal and other Ln(III)-based materials can be explored. Because many thermometric parameters are employed for temperature prediction an unprecedented very high accuracy of 0.2% in the physiological range is obtained.



subject category

Materials Science; Optics


de Souza, KMN; Silva, RN; Silva, JAB; Brites, CDS; Francis, B; Ferreira, RAS; Carlos, LD; Longo, RL

our authors


K.M.N.d.S. and R.N.S. contributed equally to this work. The Brazilian agencies FACEPE, CNPq, CAPES, and FINEP are acknowledged for providing partial financial support under grants PRONEX APQ-0675-1.06/14, APQ-0236-1.06/14, and APQ-1007-1.06/15. The work was also developed within the scope of the projects CICECO-Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020), NanoHeatControl (POCI-01-0145-FEDER-031469), and The Shape of Water (PTDC/NAN-PRO/3881/2020) financed by Portuguese funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The support of the European Union's Horizon 2020 FET Open program under Grant Agreement No. 801305 (NanoTBTech) is also acknowledged. K.M.N.S. thanks CNPq for a Ph.D. scholarship (1443501 and 88881.132112/2016-01 grants) and FACEPE (BFP-0024-1.06/20) for a postdoctoral fellowship. R.N.S. thanks NanoHeatControl for a grant and R.L.L. acknowledges CNPq for the PQ-fellowship (Proc. no. 308823/2014-1). A.R. Bastos (University of Aveiro) is acknowledged for the ellipsometry measurements.

Share this project:

Related Publications

We use cookies for marketing activities and to offer you a better experience. By clicking “Accept Cookies” you agree with our cookie policy. Read about how we use cookies by clicking "Privacy and Cookie Policy".