Ultrasensitive Thermochromic Upconversion in Core-Shell-Shell Nanoparticles for Nanothermometry and Anticounterfeiting

Huiming Liu; Long Yan; Jinshu Huang; Zhengce An; Wang Sheng; Bo Zhou

doi:10.1021/acs.jpclett.2c00005

Ultrasensitive Thermochromic Upconversion in Core-Shell-Shell Nanoparticles for Nanothermometry and Anticounterfeiting

J Phys Chem Lett. 2022 Mar 17;13(10):2306-2312. doi: 10.1021/acs.jpclett.2c00005. Epub 2022 Mar 4.

Authors

Huiming Liu¹, Long Yan¹, Jinshu Huang¹, Zhengce An¹, Wang Sheng¹, Bo Zhou¹

Affiliation

¹ State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641, China.

PMID: 35244404
DOI: 10.1021/acs.jpclett.2c00005

Abstract

Upconversion nanoparticle based ratiometric nanothermometry has shown many advantages including high relative sensitivity, fast temperature response, and high spatial resolution. However, most of the existing designs are on the basis of thermally coupled upconversion emissions, and it remains a challenge to improve the thermo-sensitivity. Here, we report a new nanoplatform of NaYF₄:Yb/Er/Ce@NaYF₄@NaYF₄:Yb/Tm core-shell-shell nanostructure to improve the thermal sensitivity through the nonthermally coupled upconversion emissions. With the increase of temperature, the green upconversion of Er³⁺ shows a decline while the blue upconversion of Tm³⁺ exhibits a rapid increase, leading to a huge contrast in both intensity ratio and emission colors. The maximum relative sensitivity can reach up to 9.86% K^-1 at 303 K. It is further found that introducing Ce³⁺ is able to improve the sensitivity and expand the thermochromic green-to-blue gamut greatly. These results show great potential in ultrasensitive lanthanide-based nanothermometry and anticounterfeiting.