Europium(III)-Doped Gadolinium(III) Complex for High-Sensitivity Temperature Sensing in the Physiological Range

Kevin Soler-Carracedo; María Díaz-González; Inocencio R Martin; Susana Rios; Beatriz Gil-Hernández; Gabriela Brito-Santos; Joaquín Sanchiz

doi:10.3390/ma15217501

Europium(III)-Doped Gadolinium(III) Complex for High-Sensitivity Temperature Sensing in the Physiological Range

Materials (Basel). 2022 Oct 26;15(21):7501. doi: 10.3390/ma15217501.

Authors

Kevin Soler-Carracedo¹, María Díaz-González¹, Inocencio R Martin^{1

2}, Susana Rios¹, Beatriz Gil-Hernández^{2

3}, Gabriela Brito-Santos³, Joaquín Sanchiz^{2

3}

Affiliations

¹ Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain.
² Instituto Universitario de Materiales y Nanotecnología (IMN), Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain.
³ Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain.

Abstract

A new Eu³⁺-doped Gd³⁺ complex of formula [Eu_0.0135Gd_0.9865(pta)₃me-phen] was synthesized and structurally characterized (Hpta = benzoyltrifluoroacetone, me-phen = 5-methyl-1,10-phenanthroline). The photoluminescence study revealed that when the compound was excited at RT, under a 457 nm continuous laser, the material exhibited high luminescence due to the antenna effect of the ligands, as well as a good balance between the phosphorescence from the spin-forbidden triplet (from the organic ligands), and the characteristic lanthanide f-f transitions. The ratio between the previous emissions drastically changed when the sample was heated up to 62 °C inside a tubular furnace. This ratio was investigated using the luminescence intensity ratio method, to analyze the capabilities of the sample as a temperature sensor. The relative sensitivity reached a maximum of 11.4 °C^-1 %, maintaining a detection limit below 0.15 °C for the whole temperature range.

Keywords: downshifting; hybrid organic-inorganic complex; luminescence; optical temperature sensor.

Grants and funding

This work was financially supported by Ministerio de Ciencia e Innovacion of Spain (MICIIN) under the National Program of Sciences and Technological Materials (PID2019-106383GB-C44 and PID2019-107335RA-I00) and Gobierno de Canarias (PROID2021010102 and PROID2020010067) and EU-FEDER funds.