Synthesis of luminescent oxide nanocrystals for thermo sensing

Luminescence nanothermometry consists in measuring the temperature at the nanoscale without using contact probes which can, at this scale, affect the measurement ...
Luminescence nanothermometry consists in measuring the temperature at the nanoscale without using contact probes which can, at this scale, affect the measurement. Although it was used in the early 2000s for hot spot localization in micro-electronic circuits, it has recently experienced a renewed interest because of its forecast applications in bio-medicine and biology. The development of luminescent nanothermometers, that can address these challenges, has strongly boomed over the last years. Such nanothermometers have to fulfill numerous specifications, including (1) a high temperature sensitivity, essential to obtain a robust temperature reading with a minimum uncertainty, (2) a strong photoluminescence efficiency, also contributing to minimize the temperature uncertainty, (3) a good biocompatibility to allow efficient cell uptake (and even mitochondrial uptake for intracellular study) and blood circulation and (4) a low sensitivity to others parameters (pH, ionic concentration, etc). The goal of this internship is to develop new luminescent nanothermometers that exhibit high thermal sensitivity, with the goal of obtaining a temperature reading with a precision better than 0.2°C.
For this purpose, we will investigate oxide nanocrystals, doped with lanthanide and/or transition metal ions. The elaboration of oxide nanocrystals will be performed in solution, in autoclave, under moderate pressures (200-400 bar) and temperatures (about 200°C). This solvothermal method, carried out under much gentler conditions than high temperature syntheses (>1000°C), will make it possible to obtain non-aggregated nanocrystals of high crystalline quality. This is crucial to obtain functionalized nanoprobes with good photoluminescence (PL) properties in vivo. This internship will focus on the elaboration and functionalization of nanocrystals, their structural characterizations (X-ray diffraction, transmission electron microscopy, DLS...), vibrational spectroscopies, PL spectroscopies and nanothermometry characterizations.

Published on October 15, 2021
Updated on September 9, 2022