Lanthanide-based ratiometric luminescence nanothermometry

Luminescent nanothermometry can precisely and remotely measure the internal temperature of objects at nanoscale precision, which, therefore, has been placed at the forefront of scientific attention. In particular, due to the high photochemical stability, low toxicity, rich working mechanisms, and superior thermometric performance, lanthanide-based ratiometric luminesencent thermometers are finding prevalent uses in integrated electronics and optoelectronics, property analysis of in-situ tracking, biomedical diagnosis and therapy, and wearable e-health monitoring. Despite recent progresses, it remains debate in terms of the underlying temperature-sensing mechanisms, the quantitative characterization of performance, and the reliability of temperature readouts. In this review, we show the origin of thermal response luminescence, rationalize the ratiometric scheme or thermometric mechanisms, delve into the problems in the characterization of thermometric performance, discuss the universal rules for the quantitative comparison, and showcase the cutting-edge design and emerging applications of lanthanide-based ratiometric thermometers. Finally, we cast a look at the challenges and emerging opportunities for further advances in this field.

Automated summary

Luminescent nanothermometry is a promising technique for accurately measuring the internal temperature of nanoscale objects. Lanthanide-based ratiometric luminescent thermometers, with their high photochemical stability, low toxicity, and superior thermometric performance, have found widespread applications in various fields. However, there are still debates regarding the underlying temperature-sensing mechanisms, the quantitative characterization of performance, and the reliability of temperature readouts. This review provides insights into the origin of thermal response luminescence, rationalizes the ratiometric scheme or thermometric mechanisms, discusses the problems in the characterization of thermometric performance, and showcases the cutting-edge design and emerging applications of lanthanide-based ratiometric thermometers. The challenges and opportunities for further advances in this field are also discussed.