Holography and Coherent Diffraction with Low-Energy Electrons: A Route towards Structural Biology at the Single Molecule Level

Abstract

The current state of the art in structural biology is led by NMR, X-ray crystallography and TEM investigations. These powerful tools however all rely on averaging over a large ensemble of molecules. Here, we present an alternative concept aiming at structural analysis at the single molecule level. We show that by combining electron holography and coherent diffraction imaging estimations concerning the phase of the scattered wave become needless as the phase information is extracted from the data directly and unambiguously. Performed with low-energy electrons the resolution of this lens-less microscope is just limited by the De Broglie wavelength of the electron wave and the numerical aperture, given by detector geometry. In imaging freestanding graphene, a resolution of 2 Angstrom has been achieved revealing the 660.000 unit cells of the graphene sheet from one data set at once. Applied to individual biomolecules the method allows for non-destructive imaging and imports the potential to distinguish between different conformations of proteins with atomic resolution.

17 pages, 10 figures; Ultramicroscopy 2015

References in corpus (9)

• Electric Field Effect in Atomically Thin Carbon Films
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Cited by in corpus (8)

• Imaging proteins at the truly single-molecule level
• Control of quantum electrodynamical processes by shaping electron wavepackets
• Low-energy electron holographic imaging of individual tobacco mosaic virions
• Quantum interaction of sub-relativistic aloof electrons with mesoscopic samples
• Dynamics of single Au nanoparticles on graphene simultaneously in real- and diffraction space by time-series convergent beam electron diffraction
• Phase retrieval methods applied to coherent imaging
• Mass spectrometry for semi-experimental protein structure determination and modeling
• How to image single isolated atoms by using coherent low-energy electrons