Tb³⁺-doped LaF₃nanocrystals for correlative cathodoluminescence electron microscopy imaging with nanometric resolution in focused ion beam-sectioned biological samples

Abstract

Here, we report the use of rare earth element-doped nanocrystals as probes for correlative cathodoluminescence electron microscopy (CCLEM) bioimaging. This first experimental demonstration shows potential for the simultaneous acquisition of luminescence and electron microscopy images with nanometric resolution in focused ion beam cut biological samples.

In Vivo Shaping of Inorganic Functional Devices using Microalgae

“…CL depends on the presence of activators like lanthanides in a lattice structure, these are stimulated to emit light when bombarded by electrons 29. For lanthanides the CL emission wavelengths are characteristic for the respective ion,37 that is, a lanthanide element as terbium can be identified by its specific emission peaks, mostly independent from its incorporation in any host material 38,39. The spectral analysis of the CL emissions combined with spectral filtered photomultiplier (PMT) imaging allows for the detection of lanthanides below the detection limit of other microanalytical methods, such as energy‐dispersive X‐ray spectroscopy 37.…”

“…Coccoliths with Tb/Ca atomic ratios of 0.0013 showed four CL emission peaks characteristic for Tb 3+ ( Figure 3 ). 26,29,37,39 The main peak appears at 545 nm, thus the Tb 3+ ‐doped coccoliths emit green light. As compared to the luminescence behavior of other Tb‐doped host matrices38,39 the luminescence pattern of our coccoliths with incorporated Tb is almost indistinguishable.…”

“…26,29,37,39 The main peak appears at 545 nm, thus the Tb 3+ ‐doped coccoliths emit green light. As compared to the luminescence behavior of other Tb‐doped host matrices38,39 the luminescence pattern of our coccoliths with incorporated Tb is almost indistinguishable. In contrast to the Tb 3+ containing coccoliths, the reference coccoliths and the substrate did not show these characteristic peaks.…”

ColorEM: analytical electron microscopy for element-guided identification and imaging of the building blocks of life

“…In the past decade, the use of more electron-resistant nanoparticles as CL probes has been explored. Particles of yttrium oxide (Fukushima et al 2014 , 2016 ) and lanthanum trifluoride (Keevend et al 2017 ) doped with lanthanides have CL emissions that can be tuned by controlling the type of lanthanide impurity. Nanodiamonds have been shown to have CL capabilities with different defect centers in the diamond emitting different color light (Nagayama et al 2016 ).…”

“…Nanodiamonds with different coatings have been visualized with CL to determine different cellular uptake routes, namely clathrin-mediated endocytosis and micropinocytosis (Nagarajan et al 2016 ). Several labs imaged CL successfully from internalized nanoparticles (Table 2 ), for instance nanoparticles doped with rare earth elements [erbium, thulium, ytterbium; Fukushima et al ( 2016 )] and terbium-doped lanthanumfluoride (LaF 3 ) nanocrystals (Keevend et al 2017 ).…”