Using a common laboratory filter paper decorated with gold nanoparticles, researchers at Washington Univ. in St. Louis have created a unique platform, known as “plasmonic paper,” for detecting and characterizing even trace amounts of chemicals and biologically important molecules, including explosives, chemical warfare agents, environmental pollutants and disease markers.
When Illinois researchers set out to investigate a method to control how DNA moves through a tiny sequencing device, they didn’t know they were about to witness a display of molecular gymnastics. Fast, accurate and affordable DNA sequencing is the first step toward personalized medicine.
Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard Univ. have unveiled a new method to form tiny 3-D metal nanoparticles in prescribed shapes and dimensions using DNA, nature's building block, as a construction mold. The ability to mold inorganic nanoparticles out of materials such as gold and silver in precisely designed 3-D shapes is a significant breakthrough.
When a sturdy material becomes soft and spongy, one usually suspects damage. But this is not always the case, especially in biological cells. By looking at microscopic biopolymer networks, researchers in Germany revealed that such materials soften by undergoing a transition from an entangled spaghetti of filaments to aligned layers of bow-shaped filaments that slide past each other. This finding may explain how other filaments flow.
A long-sought goal of creating particles that can emit a colorful fluorescent glow in a biological environment, and that could be precisely manipulated into position within living cells, has been achieved by a team of researchers at Massachusetts Institute of Technology and several other institutions. The new technology could make it possible to track the position of the nanoparticles as they move within the body or inside a cell.
An emerging class of electrically conductive plastics called "radical polymers” may bring low-cost, transparent solar cells, flexible and lightweight batteries, and ultrathin antistatic coatings for consumer electronics and aircraft. Researchers have established the solid-state electrical properties of one such polymer, called PTMA, which is about 10 times more electrically conductive than common semiconducting polymers.
Researchers have developed a new method for harvesting the energy carried by particles known as “dark” spin-triplet excitons with close to 100% efficiency, clearing the way for hybrid solar cells which could far surpass current efficiency limits. To date, this type of energy transfer had only been shown for “bright” spin-singlet excitons.
Researchers at NIST and the Univ. of Michigan have demonstrated a technique based on the quantum properties of atoms that directly links measurements of electric field strength to the International System of Units. The new method could improve the sensitivity, precision and ease of tests and calibrations of antennas, sensors, and biomedical and nano-electronic systems and facilitate the design of novel devices.
A proposal to develop a new way to remotely control brain cells from Sarah Stanley, a research associate in Rockefeller Univ.’s Laboratory of Molecular Genetics is among the first to receive funding from President Barack Obama’s BRAIN initiative. The project will make use of a technique called radiogenetics that combines the use of radio waves or magnetic fields with nanoparticles to turn neurons on or off.
A new crystallographic technique, called fast time-resolved crystallography, developed in the U.K. is set to transform scientists’ ability to observe how molecules work. Although this method, also known as Laue crystallography, has previously been possible, it has required advanced instrumentation that is only available at three sites worldwide. Only a handful of proteins have been studied using the traditional technique.
Anyone who has blown a bubble and seen how quickly it pops has first-hand experience on the major challenge in creating stable foams. At its most basic level, foam is a bunch of bubbles squished together. Liquid foams, a state of matter that arises from tiny gas bubbles dispersed in a liquid, are familiar in everyday life, from beer to bathwater. They also are important in commercial products and processes.
It’s a well-known phenomenon in electronics: Shining light on a semiconductor, such as the silicon used in computer chips and solar cells, will make it more conductive. But now researchers have discovered that in a special semiconductor, light can have the opposite effect, making the material less conductive instead. This new mechanism of photoconduction could lead to next-generation excitonic devices.
Axons are the shafts of neurons, on the tips of which connections are made with other neurons or cells. In a new study in Texas, researchers were able to use microfluidic stimulations to change the path of an axon at an angle of up to 90 degrees. The publication adds insight to the long accepted idea that chemical cues are primarily responsible for axonal pathfinding during human development and nervous system regeneration.
Conventional silicon solar cells could have an inexpensive competitor in the near future. Researchers in Europe have examined the working principle of a cell where an organic-inorganic perovskite compound acts as a light absorber. The scientists observed that charge carriers accumulate in a layer in these photovoltaic elements. If this jam can be dissolved, the already considerable efficiency of these solar cells could be further improved.
Massachusetts Institute of Technology researchers have developed a new way of creating surfaces on which droplets of any desired shape can spontaneously form. They say this approach could lead to new biomedical assay devices and light-emitting diode display screens, among other applications. The new work represents the first time that scientists can control the shape of the contact area of the droplets.
Imagine being able to tune the properties of a solid material just by flashing pulses of light on it. That is one potential payoff of electrons and atoms interacting with ultrashort pulses of light. The technology of ultrafast spectroscopy is a key to understanding this phenomenon and now a new wrinkle to that technology, observations of electron self-energy, has been introduced by Lawrence Berkeley National Laboratory researchers.
Nanoparticles could revolutionize the medical industry, but they must first target a specific region in the body, be trackable, and perform their function at the right moment. Researchers in Japan have made progress in this direction with a new type of nanomaterial: the nanosheet. Specifically, they have designed a strong, stable and optically traceable smart 2-D material that responds to pH, or the acidity or basicity of its environment.
At the Vienna Univ. of Technology gold nanoparticles have been coupled to a glass fiber. The particles emit light into the fiber in such a way that it does not travel in both directions, as one would expect. Instead, the light can be directed either to the left or to the right. This became possible by employing the spin-orbit coupling of light, creating a new kind of optical switch that has the potential to revolutionize nanophotonics.
Arrays of tiny conical tips that eject ionized materials are being made at the Massachusetts Institute of Technology. The technology, which harnesses electrostatic forces, has a range of promising applications, such as spinning out nanofibers for use in “smart” textiles or propulsion systems for fist-sized “nanosatellites.” The latest prototype array that generates 10 times the ion current per emitter that previous arrays did.
Individuals in industrial associations, educational institutions and government organizations who are interested in composites, or materials made from constituent materials with different physical or chemical properties, now have free, 24/7 access to simulation tools through an online community with offices in the Purdue Research Park.
You can brush your teeth, and wash yourself and your clothes with a clear conscience. The most common soaps, shampoos and detergents actually pose a minimal risk to the environment. This is the conclusion of a comprehensive survey that covers more than 250 scientific studies over several decades.
The world’s first “solar battery”, invented by researchers at Ohio State Univ., is a battery and a solar cell combined into one hybrid device. Key to the innovation is a mesh solar panel, which allows air to enter the battery, and a special process for transferring electrons between the solar panel and the battery electrode. Inside the device, light and oxygen enable different parts of the chemical reactions that charge the battery.
Nanostructures of virtually any possible shape can now be made using a combination of techniques developed to exploit the unique properties of so-called perovskites. The group based in the Netherlands, developed a pulsed laser deposition technique to create patterns in ultra thin layers, one atomic layer at a time. The perovskites’ crystal structure is undamaged by this soft lithography technique, maintaining electrical conductivity.
Drawn relentlessly by their electrical charges, lithium ions in a battery surge from anode to cathode and back again. Yet, no one really understands what goes on at the atomic scale as lithium ion batteries are used and recharged. Using transmission electron microscopy, researchers are now glimpsing what can happen to anodes as lithium ions work their way into them. The “atomic shuffling” these ions perform leads to rapid anode failure.
A Duke Univ. team has found that nanoparticles called single-walled carbon nanotubes accumulate quickly in the bottom sediments of an experimental wetland setting, an action they say could indirectly damage the aquatic food chain. According to the research, the risk to humans ingesting the particles through drinking water is slight, but aquatic food chains might be harmed by molecules "piggybacking" on the carbon nanoparticles.