Rare-earth element doped nanoparticles for (multi)colour correlative cathodoluminescence electron microscopy bioimaging
- Abstract number
- 317
- Event
- European Microscopy Congress 2020
- DOI
- 10.22443/rms.emc2020.317
- Corresponding Email
- [email protected]
- Session
- LST.5 - Correlative Microscopy across the scales
- Authors
- Dr. Kerda Keevend (2, 1), Mr. Michael Stiefel (1), Prof. Inge Herrmann (2, 1)
- Affiliations
-
1. Empa
2. ETH Zurich
- Keywords
cathodoluminescence, immunotargeting, nanocrystals, super-resolution
- Abstract text
Modern biomedical research heavily relies on the assessment of structure-function relationships at the nanoscale using fluorescence and electron microscopy. Fluorescence microscopy (FM) enables localization of specific proteins and study of their functions, however, the majority of molecules stay unlabelled and therefore the context remains unknown.[1] Electron microscopy (EM) allows holistic view of the cellular ultrastructure with nanometre-scale resolution, but localization of biomolecules on the greyscale images is challenging.[2] While immunogold labelling based on small gold nanoparticles is a widely adopted method for epitope recognition in EM,[3] it still poses challenges, e.g. co-localization studies and distinction of the labels from other electron-dense granules.[4, 5]
Instead of differentiating labels based on their size and composition, particles may be engineered to exhibit characteristic luminescence properties. Interestingly, accelerated electrons directly in the electron microscope generate luminescence signal, creating an effect called cathodoluminescence (CL). Here, we present correlative cathodoluminescence electron microscopy (CCLEM) bioimaging method and showcase the potential of rare-earth element (REE)-based nanoparticles for immunolabelling applications.[6] The influence of electron beam parameters on cathodoluminescence image quality and resolution in biological samples will be presented. We demonstrate how REE doped nanoparticles can be easily distinguished from naturally occurring cellular features based on the characteristic optical emission,[7] overcoming one of the main immunogold limitations. Additionally, we present (multi)colour immunolabelling application using REE doped nanoparticles and emission from single nanoparticles in resin-embedded biological samples.
- References
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6. Keevend, K., et al., Tb3+-doped LaF3 nanocrystals for correlative cathodoluminescence electron microscopy imaging with nanometric resolution in focused ion beam-sectioned biological samples. Nanoscale, 2017. 9(13): p. 4383-4387.
7. Keevend, K., et al., Ultrabright and Stable Luminescent Labels for Correlative Cathodoluminescence Electron Microscopy (CCLEM) Bioimaging. Nano Letters, 2019. 19(9): p. 6013-6018.