Correlative light and electron microscopy using cathodoluminescence from nanoparticles with distinguishable colours

Area of Science:

• Nanotechnology
• Microscopy
• Materials Science

Background:

• Correlative light and electron microscopy (CLEM) aims to integrate molecular specificity with high-resolution imaging.
• Significant technical hurdles exist, including image co-registration and optical signal instability under electron beams.

Purpose of the Study:

• To develop a novel approach for robust correlative imaging by utilizing stable optical signals.
• To enable simultaneous nanoscale mapping of molecular composition and structural imaging within a single instrument.

Main Methods:

• Imaging stable optical cathodoluminescence (CL) emitted by semiconductor nanoparticles within a scanning electron microscope (SEM).
• Utilizing nanoparticles with controllable surface chemistry and defects for spectrally-distinguishable CL emission.
• Demonstrating co-registration of CL and secondary electron (SE) images.

Main Results:

• Successfully generated well-correlated CL and SE images using three types of semiconductor nanoparticles.
• Demonstrated stable, spectrally-distinct CL signals from nanoparticle defects under electron beam irradiation.
• Achieved reliable surface functionalization of the nanoparticles for targeted labeling.

Conclusions:

• The developed nanoparticle-based CL imaging offers a solution to key challenges in CLEM.
• This technique facilitates nanoscale mapping of molecular composition via CL color, concurrently with structural electron imaging.
• Paves the way for advanced correlative microscopy applications in various scientific fields.