By using a device only six-millionths of a meter long, researchers at Cornell University have been able to detect the presence of as few as a half-dozen viruses -- and they believe the device is sensitive enough to notice just one.
The research could lead to simple detectors capable of differentiating between a wide variety of pathogens,i ncluding viruses, bacteria and toxic organic chemicals. The experiment, an extension of earlier work in which similar devices were used to detect the mass of a single bacterium, is reported in a paper, "Virus detection using nanoelectromechanical devices," in the September 27, 2004, issue ofApplied Physics Letters by Cornell research associate Rob Ilic of the Cornell NanoScale Facility (CNF), Yanou Yang, a Cornell graduate student in biomedical engineering, and Harold Craighead, Cornell professor of applied and engineering physics. The work was done with the assistance of Michael Shuler, Cornell professor of chemical and biological engineering, and microbiologist Gary Blissard of the Boyce Thompson Institute for Plant Research on the Cornell campus.
At CNF, the researchers created arrays of tiny silicon paddles from 6 to 10 micrometers (millionths of a meter) long, half a micrometer wide, and about 150 nanometers (billionths of a meter) thick, with a one-micrometer square pad at the end. Think of a tiny fly-swatter mounted by its handle like a diving board. A large array of paddles were mounted on a piezoelectric crystal that can be made to vibrate at frequencies on the order of 5 to 10 megaHertz (mHz). The experimenters then varied the frequency of vibration of the crystal. When it matched the paddles resonant frequency, the paddles began to vibrate, as measured by focusing a laser on the paddles and noting the change in reflected light, a process called optical interferometry.
Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung
Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
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13.07.2018 | Life Sciences