Urs Staufer

Bio: Urs Staufer is an academic researcher from Delft University of Technology. The author has contributed to research in topics: Cantilever & Scanning probe microscopy. The author has an hindex of 34, co-authored 211 publications receiving 5097 citations. Previous affiliations of Urs Staufer include University of Basel & University of Neuchâtel.

H2O at the Phoenix landing site.

Abstract: The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5° and 148°). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H2O ice and vapor constantly interacted with the soil. The soil was alkaline (pH = 7.7) and contained CaCO3, aqueous minerals, and salts up to several weight percent in the indurated surface soil. Their formation likely required the presence of water.

Template synthesis of nanowires in porous polycarbonate membranes: electrochemistry and morphology

Abstract: The potentiostatic electrochemical template synthesis of nanowires (Ni, Co, Cu, Au, and polyporrole) in polycarbonate track-etched membranes with nominal pore diameters dN between 10 and 200 nm is ...

Early detection of aging cartilage and osteoarthritis in mice and patient samples using atomic force microscopy

Abstract: The pathological changes in osteoarthritis--a degenerative joint disease prevalent among older people--start at the molecular scale and spread to the higher levels of the architecture of articular cartilage to cause progressive and irreversible structural and functional damage At present, there are no treatments to cure or attenuate the degradation of cartilage Early detection and the ability to monitor the progression of osteoarthritis are therefore important for developing effective therapies Here, we show that indentation-type atomic force microscopy can monitor age-related morphological and biomechanical changes in the hips of normal and osteoarthritic mice Early damage in the cartilage of osteoarthritic patients undergoing hip or knee replacements could similarly be detected using this method Changes due to aging and osteoarthritis are clearly depicted at the nanometre scale well before morphological changes can be observed using current diagnostic methods Indentation-type atomic force microscopy may potentially be developed into a minimally invasive arthroscopic tool to diagnose the early onset of osteoarthritis in situ

Microscopy capabilities of the Microscopy, Electrochemistry, and Conductivity Analyzer

Abstract: The Phoenix microscopy station, designed for the study of Martian dust and soil,consists of a sample delivery system, an optical microscope, and an atomic force microscope. The combination of microscopies facilitates the study of features from the millimeter to nanometer scale. Light-emitting diode illumination allows for full color optical imaging of the samples as well as imaging of ultraviolet-induced visible fluorescence. The atomic force microscope uses an array of silicon tips and can operate in both static and dynamic mode.

Label-free detection of single protein molecules and protein-protein interactions using synthetic nanopores.

Abstract: Nanofabricated pores in 20 nm-thick silicon nitride membranes were used to probe various protein analytes as well as to perform an antigen−antibody binding assay. A two-compartment electrochemical cell was separated by a single nanopore, 28 nm in diameter. Adding proteins to one compartment caused current perturbations in the ion current flowing through the pore. These perturbations correlated with both the charge and the size of the protein or of a protein−protein complex. The potential of this nanotechnology for studying protein−protein interactions is highlighted with the sensitive detection of β-human chorionic gonadotropin, a hormone and clinical biomarker of pregnancy, by monitoring in real time and at a molecular level the formation of a complex between hormones and antibodies in solution. In this form, the assay compared advantageously to immunoassays, with the important difference that labels, immobilization, or amplification steps were no longer needed. In conclusion, we present proof-of-princip...

Principles of nano-optics

Abstract: 1. Introduction 2. Theoretical foundations 3. Propagation and focusing of optical fields 4. Spatial resolution and position accuracy 5. Nanoscale optical microscopy 6. Near-field optical probes 7. Probe-sample distance control 8. Light emission and optical interaction in nanoscale environments 9. Quantum emitters 10. Dipole emission near planar interfaces 11. Photonic crystals and resonators 12. Surface plasmons 13. Forces in confined fields 14. Fluctuation-induced phenomena 15. Theoretical methods in nano-optics Appendices Index.

Growth Factors, Matrices, and Forces Combine and Control Stem Cells

Abstract: Stem cell fate is influenced by a number of factors and interactions that require robust control for safe and effective regeneration of functional tissue. Coordinated interactions with soluble factors, other cells, and extracellular matrices define a local biochemical and mechanical niche with complex and dynamic regulation that stem cells sense. Decellularized tissue matrices and synthetic polymer niches are being used in the clinic, and they are also beginning to clarify fundamental aspects of how stem cells contribute to homeostasis and repair, for example, at sites of fibrosis. Multifaceted technologies are increasingly required to produce and interrogate cells ex vivo, to build predictive models, and, ultimately, to enhance stem cell integration in vivo for therapeutic benefit.

Dendrimer-Encapsulated Metal Nanoparticles: Synthesis, Characterization, and Applications to Catalysis

Abstract: This Account reports the synthesis and characterization of dendrimer-encapsulated metal nanoparticles and their applications to catalysis. These materials are prepared by sequestering metal ions within dendrimers followed by chemical reduction to yield the corresponding zerovalent metal nanoparticle. The size of such particles depends on the number of metal ions initially loaded into the dendrimer. Intradendrimer hydrogenation and carbon−carbon coupling reactions in water, organic solvents, biphasic fluorous/organic solvents, and supercritical CO2 are also described.

Solid-state nanopores

Abstract: The passage of individual molecules through nanosized pores in membranes is central to many processes in biology. Previously, experiments have been restricted to naturally occurring nanopores, but advances in technology now allow artificial solid-state nanopores to be fabricated in insulating membranes. By monitoring ion currents and forces as molecules pass through a solid-state nanopore, it is possible to investigate a wide range of phenomena involving DNA, RNA and proteins. The solid-state nanopore proves to be a surprisingly versatile new single-molecule tool for biophysics and biotechnology.