Abstract
Hollow upconversion nanoparticles with tunable central cavity size can be used as self-referenced luminescent thermometers over a wide temperature range.
Temperature represents the degree of cold and hot of an object and is a basic physical parameter in scientific and industrial applications1. Temperature measurement method that does not require additional calibration during the measurement process, that is, self-referenced thermometry, shows great application prospects2. Self-referenced thermometers based on upconversion luminescence (UCL) have obvious advantages in temperature detection because of high sensitivity, non-contact, and tolerance to extreme conditions3.
The phenomenon of UCL was discovered in the 1960s4,5, but it was not until recent decades that lanthanide-doped upconversion nanoparticles (UCNPs) developed rapidly with the advent of nanotechnology6,7. UCNPs have been extensively investigated in the field of temperature sensing due to the large anti-Stokes shifts, sharp-band emissions, long lifetimes, low toxicity, weak autofluorescence, and adequate thermal stability8,9.
With the deepening of research, this field has reached a mature level. Researchers can now synthesize a variety of UCNPs with the desired size, morphology, structure, and functions10,11,12. Compared with other morphological materials, there are relatively few studies on hollow UCNPs and their optical applications, mainly because of the difficulty in constructing hollow structures by general methods. However, hollow structure nanoparticles have the characteristics of large internal surface area and high surface permeability13, so that they are expected to have high light collection efficiency, which is conducive to obtaining excellent luminescence properties. The structural advantages of hollow UCNPs are well worth further studying.
Now, writing in this issue of Light: Science & Applications, Prof. Hongjie Zhang and colleagues at the State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, China report a one-step template-free method for the synthesis of NaBiF4:Yb,Er hollow UCNPs14. Moreover, they achieved controllable tuning of the cavity size in the nanoparticles. NaBiF4:Yb,Er hollow nanoparticles exhibit excellent luminescence properties under 980 nm near-infrared irradiation due to the advantages of the hollow structure. The authors also proposed the possible formation mechanism of hollow structure, which will provide guidance for future research on hollow UCNPs.
With the presented work, Prof. Hongjie Zhang and co-authors demonstrate that the NaBiF4:Yb,Er hollow nanoparticles could be employed as self-referenced ratiometric luminescent thermometers. Furthermore, the high stability of these nanoparticles ensures their sensing ability over a wide temperature range. In addition, the excitation wavelength of the self-referenced thermometer developed by Prof. Hongjie Zhang et al. locates in the near-infrared region, which makes them have great potential for temperature sensing in the biological field in the future.
Hence, the presented work provides a new avenue for the synthesis of hollow nanoparticles and exploring their optical applications. Nevertheless, further optimization of materials will be required to improve luminescence performance and sensor sensitivity. In the future, it is possible that hollow UCNPs can not only serve as carriers to deliver drugs in vivo but also monitor the entire delivery process and real-time temperature, which will expand the application scenarios of hollow UCNPs.
References
Wang, X. D., Wolfbeis, O. S. & Meier, R. J. Luminescent probes and sensors for temperature. Chem. Soc. Rev. 42, 7834–7869 (2013).
Suo, H. et al. Rational design of ratiometric luminescence thermometry based on thermally coupled levels for bioapplications. Laser Photonics Rev. 15, 2000319 (2021).
Qiu, X. C. et al. Ratiometric upconversion nanothermometry with dual emission at the same wavelength decoded via a time-resolved technique. Nat. Commun. 11, 4 (2020).
Auzel, F. Upconversion processes in coupled ion systems. J. Lumin. 45, 341–345 (1990).
Auzel, F. Upconversion and anti-stokes processes with f and d ions in solids. Chem. Rev. 104, 139–174 (2004).
Wang, F. & Liu, X. G. Recent advances in the chemistry of lanthanide-doped upconversion nanocrystals. Chem. Soc. Rev. 38, 976–989 (2009).
Chen, G. Y. et al. Upconversion nanoparticles: design, nanochemistry, and applications in theranostics. Chem. Rev. 114, 5161–5214 (2014).
Wu, X. F. et al. Nanoscale ultrasensitive temperature sensing based on upconversion nanoparticles with lattice self-adaptation. Nano Lett. 21, 272–278 (2021).
Zhou, B. et al. Controlling upconversion nanocrystals for emerging applications. Nat. Nanotechnol. 10, 924–936 (2015).
Zhang, Y., Zhu, X. H. & Zhang, Y. Exploring heterostructured upconversion nanoparticles: from rational engineering to diverse applications. ACS Nano 15, 3709–3735 (2021).
Liu, S. B. et al. Controlling upconversion in emerging multilayer core-shell nanostructures: from fundamentals to frontier applications. Chem. Soc. Rev. 51, 1729–1765 (2022).
Liu, D. M. et al. Three-dimensional controlled growth of monodisperse sub-50 nm heterogeneous nanocrystals. Nat. Commun. 7, 10254 (2016).
Li, L. H. et al. Niobium pentoxide hollow nanospheres with enhanced visible light photocatalytic activity. J. Mater. Chem. A 1, 11894–11900 (2013).
An, R. et al. Hollow nanoparticles synthesized via Ostwald ripening and their upconversion luminescence-mediated Boltzmann thermometry over a wide temperature range. Light Sci. Appl. 11, 217 (2022).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Sun, L. NaBiF4-based hollow upconversion nanoparticles for temperature sensing. Light Sci Appl 11, 257 (2022). https://doi.org/10.1038/s41377-022-00954-x
Published:
DOI: https://doi.org/10.1038/s41377-022-00954-x