Multi-color correlative light and electron microscopy using nanoparticle cathodoluminescence

TL;DR

This paper presents a novel multi-color correlative microscopy technique combining stable nanoparticle cathodoluminescence with electron imaging, enabling nanoscale molecular mapping with high specificity and resolution.

Contribution

Introduces a new multi-color imaging approach using stable, surface-functionalized nanoparticles for correlative light and electron microscopy with improved co-registration and spectral distinguishability.

Findings

Successful demonstration of multi-color cathodoluminescence imaging

Reliable surface functionalization of nanoparticles achieved

Potential for nanoscale molecular surface mapping

Abstract

Correlative light and electron microscopy promises to combine molecular specificity with nanoscale imaging resolution. However, there are substantial technical challenges including reliable co-registration of optical and electron images, and rapid optical signal degradation under electron beam irradiation. Here, we introduce a new approach to solve these problems: multi-color imaging of stable optical cathodoluminescence emitted in a scanning electron microscope by nanoparticles with controllable surface chemistry. We demonstrate well-correlated cathodoluminescence and secondary electron images using three species of semiconductor nanoparticles that contain defects providing stable, spectrally-distinguishable cathodoluminescence. We also demonstrate reliable surface functionalization of the particles. The results pave the way for the use of such nanoparticles for targeted labeling of surfaces to provide nanoscale mapping of molecular composition, indicated by cathodoluminescence color, simultaneously acquired with structural electron images in a single instrument.