ERC FUNDED PROJECTS

We propose to develop truly two-dimensional continuous materials and two-dimensional monolayer films composed of individual nanocrystals by the comparatively fast, inexpensive, and scalable colloidal synthesis method. The materials’ properties will be studied in detail, especially regarding their (photo-) electrical transport. This will allow developing new types of device structures, such as Coulomb blockade and field enhancement based transistors. Recently, we demonstrated the possibility to synthesize in a controlled manner truly two-dimensional colloidal nanostructures. We will investigate their formation mechanism, synthesize further materials as “nanosheets”, develop methodologies to tune their geometrical properties, and study their (photo-) electrical properties. Furthermore, we will use the Langmuir-Blodgett method to deposit highly ordered monolayers of monodisperse nanoparticles. Such structures show interesting transport properties governed by Coulomb blockade effects known from individual nanoparticles. This leads to semiconductor-like behavior in metal nanoparticle films. The understanding of the electric transport in such “multi-tunnel devices” is still very limited. Thus, we will investigate this concept in detail and take it to its limits. Beside improvement of quality and exchange of material we will tune the nanoparticles’ size and shape in order to gain a deeper understanding of the electrical properties of supercrystallographic assemblies. Furthermore, we will develop device concepts for diode and transistor structures which take into account the novel properties of the low-dimensional assemblies. Nanosheets and monolayers of nanoparticles truly follow the principle of building devices by the bottom-up approach and allow electric transport measurements in a 2D regime. Highly ordered nanomaterial systems possess easy and reliably to manipulate electronic properties what make them interesting for future (inexpensive) electronic devices.

1 497 200 €

Start date: 2013-02-01, End date: 2019-01-31

Antigenic variation is a widely employed strategy to evade the host immune response. It has similar functional requirements even in evolutionarily divergent pathogens. These include the mutually exclusive expression of antigens and the periodic, nonrandom switching in the expression of different antigens during the course of an infection. Despite decades of research the mechanisms of antigenic variation are not fully understood in any organism. The recent development of high-throughput sequencing-based assays to probe the 3D genome architecture (Hi-C) has revealed the importance of the spatial organization of DNA inside the nucleus. 3D genome architecture plays a critical role in the regulation of mutually exclusive gene expression and the frequency of translocation between different genomic loci in many eukaryotes. Thus, genome architecture may also be a key regulator of antigenic variation, yet the causal links between genome architecture and the expression of antigens have not been studied systematically. In addition, the development of CRISPR-Cas9-based approaches to perform nucleotide-specific genome editing has opened unprecedented opportunities to study the influence of DNA sequence elements on the spatial organization of DNA and how this impacts antigen expression. I have adapted both Hi-C and CRISPR-Cas9 technology to the protozoan parasite Trypanosoma brucei, one of the most important model organisms to study antigenic variation. These techniques will enable me to bridge the field of antigenic variation research with that of genome architecture. I will perform the first systematic analysis of the role of genome architecture in the mutually exclusive and hierarchical expression of antigens in any pathogen. The experiments outlined in this proposal will provide new insight, facilitating a new view of antigenic variation and may eventually help medical intervention in T. brucei and in other pathogens relying on antigenic variation for their survival.

1 498 175 €

Start date: 2017-04-01, End date: 2022-03-31

New polymer materials are necessary to match the demand for highly integrated, multifunctional, responsive systems for sensing, information processing, soft robotics or multi-parametric implants. Both established material design concepts based on lithography, and emerging engineering efforts based on additive manufacturing (AM) are currently not able to fully address the need for topologically complex, multifunctional and stimuli-responsive polymer materials. This proposal aims at establishing a radically new approach for polymer material design, rethinking AM on both material and process level. Here, functionality will be already embedded at the building block level to emerge into larger scales. The exact methodology relies on polymer microparticles as a novel material basis with arbitrary geometry, function, mechanics and responsiveness. These microparticulate formulations will serve as predefined, voxel-like building blocks in AM yielding hierarchical assemblies with spatially defined voxel position and programmable, adaptive properties, which clearly go beyond existing functional material classes. With that, 3DPartForm will address the current lack of additive manufacturing providing multifunctional, stimuli-responsive materials, in which not only strongly different, but most importantly functional building blocks with intrinsic time axis will be processed into true 4D-polymer multimaterials. Products emerging from this approach will reach a previously unknown level of system integration, where optical transparency, electric and thermal conductivity as well as diffusivity and mechanical rigidity will become spatiotemporally tunable at single-voxel level. Coupled sensing and actuation operations will be realized by processing, transforming and manipulating single or combined input stimuli within these materials in the focus of 3DPartform, and platforms for biomimetics and cell-free biotechnology will be implemented as a long-term goal.

1 474 125 €

Start date: 2020-04-01, End date: 2025-03-31

Crucial processes within cells depend on specific non-covalent interactions which mediate the assembly of proteins and other biomolecules. Deriving structural information to understand the function of these complex systems is the primary goal of Structural Biology. In this application, the recently developed LILBID method (Laser Induced Liquid Bead Ion Desorption) will be optimized for investigation of macromolecular complexes with a mass accuracy two orders of magnitude better than in 1st generation spectrometers. Controlled disassembly of the multiprotein complexes in the mass spectrometric analysis while keeping the 3D structure intact, will allow for the determination of complex stoichiometry and connectivity of the constituting proteins. Methods for such controlled disassembly will be developed in two separate units of the proposed LILBID spectrometer, in a collision chamber and in a laser dissociation chamber, enabling gas phase dissociation of protein complexes and removal of excess water/buffer molecules. As a third unit, a chamber allowing determination of ion mobility (IM) will be integrated to determine collisional cross sections (CCS). From CCS, unique information regarding the spatial arrangement of proteins in complexes or subcomplexes will then be obtainable from LILBID. The proposed design of the new spectrometer will offer fundamentally new possibilities for the investigation of non-covalent RNA, soluble and membrane protein complexes, as well as broadening the applicability of non-covalent MS towards supercomplexes.

1 264 477 €

Start date: 2014-02-01, End date: 2019-01-31