Primary Luminescent Nanothermometers for Temperature Measurements Reliability Assessment

The potential applications in disparate fields led to a rapid evolution of luminescence thermometry. In particular, luminescent thermometry based on trivalent lanthanide ions (Ln(3+)) has become very popular in the past decade due to the unique versatility, stability, and narrow emission band profiles covering a broad spectral range (from ultraviolet to the infrared) with relatively high emission quantum yields. Nevertheless, the reliability of Ln(3+) ratiometric nanothermometry measurements is recently questioned in a few works reporting fake temperature readouts caused by experimental artifacts and even intrinsic effects. Using NaYF4:Er3+/Yb3+@NaNdF4@PAA (PAA stands for polyacrylic acid) core-shell nanoparticles, it is shown that how the primary luminescent thermometer concept can be used to correct the thermometric parameter (the intensity ratio of the Er3+ H-2(11/2)-> I-4(15/2) and S-4(3/2)-> I-4(15/2) transitions) from the interference of the intruding H-2(9/2)-> I-4(13/2) emission ensuring, thereafter, reliable temperature measurements.

Automated summary

The rapid evolution of luminescence thermometry is driven by its potential applications in diverse fields, with a particular focus on luminescent thermometry based on trivalent lanthanide ions in the past decade. However, recent studies have raised concerns about fake temperature readouts in this technology, prompting the development of approaches like the use of core-shell nanoparticles for reliable temperature measurements.