Showing papers by "Stefan Seeger published in 2010"
TL;DR: A noninvasive fluorescence microscopy method based on the influence of the microscope slide on the angular intensity distribution of fluorescence is reported and nanometer resolution along the optical axis is demonstrated.
Abstract: We report a noninvasive fluorescence microscopy method and demonstrate nanometer resolution along the optical axis. The technique is based on the influence of the microscope slide on the angular intensity distribution of fluorescence. Axial positions are determined by measuring the proportion of light emitted below the critical angle of total internal reflection, which behaves in a classical way, and light emitted above the critical angle, which is exponentially dependent on the distance of the fluorophore from the microscope slide.
55 citations
TL;DR: In this article, a super-hydrophobic silicone nanofilament ablation was performed using a near-ultraviolet (UV) laser with a wavelength of 355 nm and a repetition rate of 10 kHz.
Abstract: We demonstrate that a recently developed coating composed of superhydrophobic silicone nanofilaments can be selectively functionalized to yield well defined micron-scale patterns of contrasting wettabilities (superhydrophobic/hydrophilic and amphiphobic/amphiphilic). Nanofilament ablation was performed using a near-ultraviolet (UV) laser with a wavelength of 355 nm and a repetition rate of 10 kHz. This is a highly promising approach for open channel microfluidics and microarray analysis due to its simplicity, the chemical and environmental stability of the coating, and the low cost.
32 citations
TL;DR: Label-free detection of molecules and particles based on native fluorescence excited at the ultraviolet (UV) region of the electromagnetic spectrum shows great potential for molecular analysis in life sciences as mentioned in this paper.
Abstract: Label-free detection of molecules and particles based on native fluorescence excited at the ultraviolet (UV) region of the electromagnetic spectrum shows great potential for molecular analysis in life sciences. It offers simple, low-cost, and fast methods for sensitive detection of important biological analytes in nature forms. This article reviews the most significant research on label-free native fluorescence detection in analytical chemistry and biochemistry, with particular focus on the instrumental requirements and applications that cover papers published to the beginning of 2009. Future development directions for label-free optical biosensors based on native fluorescence are discussed.
31 citations
TL;DR: The Monte Carlo-type simulation designed to implement the previously proposed mechanism through which proteins are not necessarily rejected if they approach the surface to an occupied region suggests that proteins can be tracked laterally for a certain distance due to the influence of preadsorbed proteins in order to reach the nearest available binding site.
Abstract: Cooperative effects play a vital role in protein adsorption events on biological interfaces. Despite a number of studies in this field molecular adsorption mechanisms that include cooperativity are still under debate. In this work we use a Monte Carlo-type simulation to explore the microscopic details behind cooperative protein adsorption. The simulation was designed to implement our previously proposed mechanism through which proteins are not necessarily rejected if they approach the surface to an occupied region. Instead, we suggest that proteins can be tracked laterally for a certain distance due to the influence of preadsorbed proteins in order to reach the nearest available binding site. The simulation results were compared with experimental data obtained by using the supercritical angle fluorescence (SAF) microscopy technique. It was found that the tracking distance may be up to 2.5 times the protein’s diameter depending on the investigated system. The general validity of this tracking mechanism is ...
30 citations
09 Dec 2010
TL;DR: In this article, a model system consisting of a short peptide, a silica slab, and water molecules was studied by means of classical molecular dynamics simulations, which revealed that, besides electrostatic interactions caused by the chosen charge distribution, the peptide interacts with the silica surface through formation of direct peptide surface hydrogen bonds as well as indirect peptide-water-surface hydrogen bonds.
Abstract: Protein adsorption and protein surface interactions have become an important research topic in recent years. Very recently, for example, it has been shown that protein clusters can undergo a surface-induced spreading after adsorption. Such phenomena emphasize the need of a more detailed insight into protein–silica interaction at an atomic level. Therefore, we have studied a model system consisting of a short peptide, a silica slab, and water molecules by means of classical molecular dynamics simulations. The study reveals that, besides of electrostatic interactions caused by the chosen charge distribution, the peptide interacts with the silica surface through formation of direct peptide-surface hydrogen bonds as well as indirect peptide–water-surface hydrogen bonds. The number of created hydrogen bonds varies considerably among the simulated structures. The strength of hydrogen bonding determines the mobility of the peptide on the surface and the internal flexibility of the adsorbed peptide.
13 citations