Precisely Picking Nanoparticles by a "Nano-Scalpel" for 360° Electron Tomography

Area of Science:

• Materials Science
• Nanotechnology
• Electron Microscopy

Background:

• Electron tomography (ET) is crucial for 3D nanoparticle characterization.
• The missing wedge artifact, caused by limited tilt angles in transmission electron microscopy (TEM), hinders accurate 3D reconstruction.
• Existing algorithms partially mitigate but cannot fully recover missing structural information.

Purpose of the Study:

• To develop a universal sample preparation method for full-range electron tomography (ET) of nanoparticles.
• To enable accurate 3D structural characterization of individual or small groups of nanoparticles.
• To overcome the limitations of current sample preparation techniques for 360° ET.

Main Methods:

• A novel sample preparation technique involves cutting a carbon film with supported nanoparticles.
• Selected nanoparticles are transferred to a full-range tomography holder tip using a sharp tungsten tip.
• The prepared samples undergo 360° ET for complete data acquisition.

Main Results:

• The proposed method allows for the precise transfer of individual or few separated nanoparticles.
• High-quality 3D reconstructions were achieved using 360° ET.
• The reconstructions were free from missing wedge artifacts, demonstrating the method's effectiveness.

Conclusions:

• The developed universal sample preparation method significantly advances the application of 360° ET for nanoparticle analysis.
• This technique provides a robust solution for accurate 3D structural characterization of nanoparticles.
• It overcomes previous challenges in sample preparation for full-range ET, broadening its applicability.