Science

Understanding the Interaction of Proteins with colloidal Surfaces

Whenever a biological medium comes into contact with an artificial surface, protein adsorption is observed. For colloidal nanoparticles, this adsorption layer is called the protein corona. This layer alters the chemical identity of the nanoparticle in a yet unpredictive manner. We are using advanced EM methods to characterize the mechanism of the protein-surface interaction.

Atomic Reconstruction of Peptide Fibres

Peptide nanofibres play important roles in physiological processes but also in pathologies, making them a subject of high research interest. However, predicting the atomic arrangement of those fibres is still a major challenge. We are investigating short, synthetic peptides that self-assemble into fibres in order to understand the structure forming motifs of peptide self-assembly.

2D classification approaches for particle analysis

The methods used in 3D-EM structural biology are developed to reconstruct the atomic structure of proteins. However, these sophisticated analytical methods can also be used in material science.

The determination of the particle size distribution of nanoparticles can be achieved by many complementary methods, like e.g. DLS or NTA. Also imaging based methods are already established. But in order to overcome the problems with image based particle size measurement, we transferred the 2D classification method from biological protein structure analysis to a materials science application.

AI for correlative microscopy

Correlative methods, like in microscopy, combine complementary data to achieve synergy effects. For example, combining information from fluorescence- and electron microscopy yields multimodal information. But in order to retrieve this information, both input channels need to be registered. For this registration, we are developing AI approaches in order to increase the throughput and hence the statistical relevance of correlative data.

High resolution of polymer crystals

Imaging of beam sensitive materials in the electron microscope is a major challenge. However, all crystalline material classes have been imaged at high resolution in the EM, except for polymer crystals. The very low lethal dose, combined with a small crystal unit cell, has so far made it impossible to image the crystal lattice under an electron microscope. To overcome this challenges, we use the most advanced EM devices to resolve the crystal lattice of polyethylene with an electron fluence below 10 e-/Å2.