"The individual nanotube-based probes can be used for electrochemical and biochemical sensing," said Min-Feng Yu, a U. of I. professor of mechanical science and engineering, and a researcher at the university’s Beckman Institute. "The position of the nanoelectrodes can be controlled very accurately."
To fabricate the nanoelectrodes, Yu and graduate students Kyungsuk Yum, Jie Hu and Han Na Cho begin by attaching a strong, rigid, boron-nitride nanotube to a much larger, conductive probe. The nanotube will form the insulating core of the nanoelectrode.
The researchers then coat the nanotube with a thin film of gold about 10-50 nanometers thick (a nanometer is 1 billionth of a meter.) The gold layer is then coated with an insulating polymer coating about 10 nanometers thick. Lastly, the researchers use a focused ion beam to slice off the end of the nanotube, exposing a conducting ring of gold sandwiched between an insulating core and an insulating outer ring.
The process yields nanoelectrodes with a diameter of 100 nanometers, and a length of up to 30 microns.
Because the nanotube is attached to a much larger probe, the researchers can manipulate the nanotube like a needle. They can control precisely where the nanotube penetrates a cell, for example, and even pinpoint smaller cell structures, such as the nucleus or mitochondrion.
"Nanoelectrodes offer new opportunities for electrochemical sensing in intracellular environments," said Yu, who will describe the fabrication process and demonstrate the feasibility of nanoelectrodes at the March meeting of the American Physical Society, to be held in Denver, March 5-9. "By functionalizing the active area of the nanoelectrode with an appropriate chemical, we can target the detection of specific chemical species."
The researchers have demonstrated that their nanoelectrode can sense the chemical environment within a droplet 10 microns in diameter. Their next step is to show that the probe can penetrate the cellular membrane of a living cell, without damaging the cell.
James E. Kloeppel | EurekAlert!
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16.11.2017 | University of California - Santa Cruz
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
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Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
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The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
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