Dagmar Gerthsen

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One of the biggest limitations of conventional carbon nanotube device fabrication techniques is the inability to scale up the processes to fabricate a large number of devices on a single chip. In this report, we demonstrate the directed and precise assembly of single-nanotube devices with an integration density of several million devices per square(More)
The mean inner potentials of various III-V semiconductors, Si and Ge have been calculated by density functional theory methods. For that purpose, the Coulomb potential of slabs consisting of a crystal and vacuum region has been computed and averaged inside the crystal region. The computed values are in agreement with experimental values obtained by electron(More)
Supercritical fluid reactive deposition was used for the deposition of highly dispersed platinum nanoparticles with controllable metal content and particle size distribution on beta-cyclodextrin. The average particle size and size distribution were steered by the precursor reduction conditions, resulting in particle preparations <20, <100, and >100 nm as(More)
Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the ultrastructural changes in bacteria induced by antimicrobial peptides (AMPs). Both the beta-stranded gramicidin S and the alpha-helical peptidyl-glycylleucine-carboxyamide (PGLa) are cationic amphiphilic AMPs known to interact with bacterial membranes. One(More)
We report a facile strategy to synthesize water-soluble, fluorescent gold nanoclusters (AuNCs) in one step by using a mild reductant, tetrakis(hydroxymethyl)phosphonium chloride (THPC). A zwitterionic functional ligand, D-penicillamine (DPA), as a capping agent endowed the AuNCs with excellent stability in aqueous solvent over the physiologically relevant(More)
Backscattered electron imaging of HT29 colon carcinoma cells in a scanning electron microscope was studied. Thin cell sections were placed on indium-tin-oxide-coated glass slides, which is a promising substrate material for correlative light and electron microscopy. The ultrastructure of HT29 colon carcinoma cells was imaged without poststaining by(More)
Three differently sized, highly dispersed platinum nanoparticle (Pt-NP) preparations were generated by supercritical fluid reactive deposition (SFRD) and deposited on a β-cyclodextrin matrix. The average particle size and size distribution were steered by the precursor reduction conditions, resulting in particle preparations of <20, <100 and >100 nm as(More)
The use of nanostructured silica (SiO2) particles is no longer restricted to biomedical and (bio-) technological fields but rather finding applications in products of the food industry. Thus, our studies on the toxicological relevance of SiO2 nanoparticles focused on cytotoxic effects, the modulation of the cellular redox status and the impact on DNA(More)
Imaging of weak amplitude and phase objects, such as unstained vitrified biological samples, by conventional transmission electron microscopy (TEM) suffers from poor object contrast since the amplitude and phase of the scattered electron wave change only very little. In phase contrast light microscopy the imaging of weak phase objects is greatly enhanced by(More)
Structure analysis of the cell-penetrating peptide transportan 10 (TP10) revealed an exemplary range of different conformations in the membrane-bound state. The bipartite peptide (derived N-terminally from galanin and C-terminally from mastoparan) was found to exhibit prominent characteristics of (i) amphiphilic α-helices, (ii) intrinsically disordered(More)