A5074814650- Force Microscopy Techniques and Applications
- Molecular Junctions and Nanostructures
- Advanced biosensing and bioanalysis techniques
- Nanofabrication and Lithography Techniques
- Mechanical and Optical Resonators
- nanoparticles nucleation surface interactions
- Nanotechnology research and applications
- Catalytic Processes in Materials Science
- Semiconductor materials and devices
- Polymer Surface Interaction Studies
- Analytical Chemistry and Sensors
- Spectroscopy and Quantum Chemical Studies
- Laser-Ablation Synthesis of Nanoparticles
- Nanopore and Nanochannel Transport Studies
- Glycosylation and Glycoproteins Research
- Metal and Thin Film Mechanics
- Advanced Chemical Physics Studies
- Quantum Dots Synthesis And Properties
- Gas Sensing Nanomaterials and Sensors
- Catalysis and Oxidation Reactions
- Graphene and Nanomaterials Applications
- Advanced MEMS and NEMS Technologies
- Carbohydrate Chemistry and Synthesis
- Surface Chemistry and Catalysis
- Diatoms and Algae Research
University of Bremen
2016-2025
Paul Scherrer Institute
2023
École Polytechnique Fédérale de Lausanne
2007-2023
Polytechnic University of Turin
2023
Interface (United States)
2015-2019
Environmental Technologies (United States)
2018
Fraunhofer Institute for Manufacturing Technology and Advanced Materials
2009-2014
Fraunhofer Society
2013
Fraunhofer Institute for Mechanics of Materials
2006-2010
Fraunhofer Institute for Production Technology IPT
2009
Most membrane proteins are modified by covalent addition of complex sugars through N- and O-glycosylation. Unlike proteins, glycans do not typically adopt specific secondary structures remain very mobile, shielding potentially large fractions protein surface. High glycan conformational freedom hinders complete structural elucidation glycoproteins. Computer simulations may be used to model glycosylated but require hundreds thousands computing hours on supercomputers, thus limiting routine...
The microscopic mechanism of platinum cluster nucleation on DNA templates is studied by first-principle molecular dynamics simulations. We find that Pt(II) complexes bound to can form strong Pt−Pt bonds with free Pt after a single reduction step, and may thus act as preferential sites. This confirmed series experiments, in which we achieve purely heterogeneous growth DNA, use it fabricate metal necklaces unprecedented thinness regularity.
We investigate the conditions which should be fulfilled to grow chains of nanosized noble metal clusters on DNA templates according a selectively heterogeneous, template-controlled mechanism. A long incubation double-stranded molecules with Pt(II) complexes is necessary obtain template-directed formation thin and uniform cluster after chemical reduction DNA/salt solution. Without this "activation" step, acts as nonspecific capping agent for formed does not hinder random aggregates. The...
Lights, camera, action! The general mechanism of biomolecular recognition introduced by Pauling more than 50 years ago has now been brought to the movie screen (see still frame; D: D-Phe-D-Phe, L: L-Phe-L-Phe). With STM movies, chiral-recognition process individual adsorbed di-phenylalanine molecules is followed illustrate dynamic induced-fit at single-molecule level. Supporting information for this article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z700194_s.html...
We present evidence that specific material recognition by small peptides is governed local solvent density variations at solid/liquid interfaces, sensed the side-chain residues with atomic-scale precision. In particular, we unveil origin of selectivity binding motif RKLPDA for Ti over Si using a combination metadynamics and steered molecular dynamics simulations, obtaining adsorption free energies adhesion forces in quantitative agreement corresponding experiments. For an accurate...
The catalytic oxidation activity of platinum particles in automobile catalysts is thought to originate from the presence highly reactive superficial oxide phases which form under oxygen-rich reaction conditions. Here we study thermodynamic stability surfaces and thin films their reactivities toward carbon compounds by means first-principles atomistic thermodynamics calculations molecular dynamics simulations based on density functional theory. On Pt(111) surface most stable phase found be a...
Graphene-based nanomaterials have exhibited wide applications in nanotechnology, materials science, analytical and biomedical engineering due to their unique physical chemical properties. In particular, graphene has been an excellent nanocarrier for drug delivery application because of its two-dimensional structure, large surface area, high stability, good biocompatibility, easy modification. this review, we present the recent advances synthesis graphene-based nanomaterials. The modification...
We present an orbital-resolved extension of the Hubbard U correction to density-functional theory (DFT). Compared conventional shell-averaged approach, prediction energetic, electronic and structural properties is strongly improved, particularly for compounds characterized by both localized hybridized states in manifold. The numerical values all parameters are readily obtained from linear-response calculations. relevance this more refined approach showcased its application bulk solids pyrite...
The initial nucleation of platinum clusters after the reduction K(2)PtCl(4) in aqueous solution is studied by means first principles molecular dynamics simulations. A reaction mechanism leading to a Pt dimer revealed both gas-phase simulations and which model environment. key step observed process formation Pt-Pt bond between Pt(I) complex an unreduced Pt(II) complex. In light this result, we discuss nanoparticles. generally accepted model, particles starts only when critical concentration...
For over a century, platinum oxides find technologically relevant applications in various fields ranging from catalysis to electrochemistry and nanoelectronics. We have performed density functional theory study of the PtO, ${\mathrm{Pt}}_{3}{\mathrm{O}}_{4}$, $\mathrm{Pt}{\mathrm{O}}_{2}$ bulk oxide phases. In our calculations, PtO ${\mathrm{Pt}}_{3}{\mathrm{O}}_{4}$ present metallic character at simple generalized gradient approximation level. The application Hubbard corrections Kohn-Sham...
We have developed a classical two- and three-body interaction potential to simulate the hydroxylated, natively oxidized Si surface in contact with water solutions, based on combination extension of Stillinger-Weber originally SiO2 polymorphs. The parameters are chosen reproduce structure, charge distribution, tensile stress, interactions single molecules model previously obtained by means accurate density functional theory simulations. applied case hydrophilic silicon wafer bonding at room...
Abstract We present a set of Coulomb point charges and van der Waals parameters for molecular dynamics simulations interfaces between natively deprotonated amorphous SiO 2 surfaces liquid water, to be used in combination with standard biomolecular force fields. pay particular attention the extent negative charge delocalisation solid that follows deprotonation terminal silanol groups, as revealed by extensive Bader analysis electronic densities computed density functional theory (DFT). The...
Fundamental knowledge about the mechanisms of adhesion between oxide particles with diameters few nanometers is impeded by difficulties associated direct measurements contact forces at such a small size scale. Here we develop strategy based on AFM force spectroscopy combined all-atom molecular dynamics simulations to quantify and explain nature 10 nm TiO(2) nanoparticles. The method statistical analysis peaks measured in repeated approaching/retracting loops an cantilever into film...
AFM-based force spectroscopy shows wide bio-related applications especially for bioimaging and biosensing.
The structural transformation of WO<sub>3</sub> at high temperatures.
We propose an atomistic model for the nucleation of aluminum oxide on Al(111) surface derived from first principles molecular dynamics simulations. The process begins with dissociative adsorption ${\mathrm{O}}_{2}$ molecules metal surface, which occurs via a ``hot-atom'' mechanism driven by partial filling ${\ensuremath{\sigma}}^{*}$ antibonding orbital ${\mathrm{O}}_{2}$. During subsequent hyperthermal motion, O atoms can be spontaneously incorporated underneath topmost Al layer, initiating...
We study the interactions between Fe(II) aqua complexes and surfaces of goethite $(\ensuremath{\alpha}\text{-FeOOH})$ by means density functional theory calculations including so-called Hubbard $U$ correction to exchange-correlation functional. Using a thermodynamic approach, we find that (110) (021) in contact with aqueous solutions are almost equally stable, despite evident needlelike shape crystals indicating substantially different reactivity two faces. thus suggest crystal anisotropy...
The behavior of titanium implants in physiological environments is governed by the thin oxide layer that forms spontaneously on metal surface and mediates interactions with adsorbate molecules. In order to study adsorption biomolecules a realistic fashion, we first build up model an oxidized Ti contact liquid water means extensive first-principles molecular dynamics simulations. Taking obtained structure as reference, then develop classical potential Ti/TiOx/water interface. This based...
The adsorption of α-chymotrypsin and hen egg white lysozyme on amorphous silica is studied by molecular dynamics (MD) simulations in comparison with experiments. Protein–surface interaction profiles are computed implicit solvent at the level DLVO theory. These reveal a preferential orientation for chymotrypsin, driven its large dipole moment, α-helical regions pointing toward surface. Instead, less clear orientational preference characterizes adsorption, which approaches surface side-on...