The unique properties of engineered nanoparticles have created intense interest in their environmental behavior. Due to the increased use of nanotechnology in consumer products, industrial applications and health care technology, nanoparticles are more likely to enter the environment. For this reason, it’s not only important to know the type, size and distribution of nanoparticles, but it’s also crucial to understand their impact.
A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum dot work by Los Alamos National Laboratory researchers in collaboration with scientists from Univ. of Milano-Bicocca, Italy. Their project demonstrates that superior light-emitting properties of quantum dots can be applied in solar energy by helping more efficiently harvest sunlight.
Thousands of consumer products contain nanoparticles added by manufacturers to improve texture, kill microbes or enhance shelf life, among other purposes. However, several studies have shown that some of these engineered nanoparticles can be toxic to cells. A new study from Massachusetts Institute of Technology and the Harvard School of Public Health suggests that certain nanoparticles can also harm DNA.
New research shows that nanostructures could enable more light to be directed into the active layer of solar cells, increasing their efficiency. Prof. Martina Schmid of Freie Univ. in Berlin has measured how irregularly distributed silver particles influence the absorption of light. Nanoparticles interact with one another via their electromagnetic near-fields, so that local “hot spots” arise where light is concentrated especially strongly.
A combined computational and experimental study of self-assembled silver-based structures known as superlattices has revealed an unusual and unexpected behavior: arrays of gear-like molecular-scale machines that rotate in unison when pressure is applied to them.
Scientists at Rice Univ. have mixed very low concentrations of diamond nanoparticles with mineral oil to test the nanofluid’s thermal conductivity and how temperature would affect its viscosity. They found it to be much better than nanofluids that contain higher amounts of oxide, nitride or carbide ceramics, metals, semiconductors, carbon nanotubes and other composite materials. In short, it is the best nanofluid for heat transfer.
Researchers in the U.K. have developed a new antibacterial material which has potential for cutting hospital acquired infections. The combination of two simple dyes with nanoscopic particles of gold is deadly to bacteria when activated by light, even under modest indoor lighting. And in a first for this type of substance, it also shows impressive antibacterial properties in total darkness.
Phosphorus can be found in fertilizers, drinks and detergents, and it accumulates in waterways, polluting them. For this reason, researchers in Germany have developed a new platform for recovering this valuable but harmful element from water. They have attached bonding sites for phosphorus to particles so that they fish the phosphate anions out of the water and carry them “piggyback”. The particles can be applied using a magnet.
Massachusetts Institute of Technology engineers have coaxed bacterial cells to produce biofilms that can incorporate non-living materials, such as gold nanoparticles and quantum dots. These “living materials” combine the advantages of live cells, which respond to their environment and produce complex biological molecules, with the benefits of nonliving materials, which add functions such as conducting electricity or emitting light.
Researchers have succeeded for the first time to produce uniform antimony nanocrystals. Tested as components of laboratory batteries, these are able to store a large number of both lithium and sodium ions. These nanomaterials operate with high rate and may eventually be used as alternative anode materials in future high-energy-density batteries.
The term a “brighter future” might be a cliché, but in the case of ultra-small probes for lighting up individual proteins, it is now most appropriate. Researchers at Lawrence Berkeley National Laboratory have discovered surprising new rules for creating ultra-bright light-emitting crystals that are less than 10 nm in diameter.
Researchers at the Harvard Univ. School of Engineering and Applied Sciences are giving man-made materials structural color. Producing structural color is not easy, though; it often requires a material’s molecules to be in a very specific crystalline pattern, like the natural structure of an opal, which reflects a wide array of colors.
Plants have many valuable functions: They provide food and fuel, release the oxygen that we breathe and add beauty to our surroundings. Now, a team of Massachusetts Institute of Technology researchers wants to make plants even more useful by augmenting them with nanomaterials that could enhance their energy production and give them completely new functions, such as monitoring environmental pollutants.
Biomedical engineering researchers have developed a new technique that uses adenosine-5’-triphosphate (ATP), the so-called “energy molecule,” to trigger the release of anti-cancer drugs directly into cancer cells. Early laboratory tests show it increases the effectiveness of drugs targeting breast cancer. The technique was developed by researchers at North Carolina State Univ. and the Univ. of North Carolina at Chapel Hill.
In physics, there's small, and then there's nullity, as in zero-dimensional. Univ. of Cincinnati researchers have reached this threshold with a special structure, zero-dimensional quantum dots, that may someday lead to better ways of harnessing solar energy, stronger lasers or more sensitive medical diagnostic devices.
Cornell Univ. researchers have recently led what is probably the most comprehensive study to date of block copolymer nanoparticle self-assembly processes. The work is important, because using polymers to self-assemble inorganic nanoparticles into porous structures could revolutionize electronics.
It has long been known that free, ionic silver particles can be highly toxic to aquatic organisms. Yet we a lack of detailed knowledge about the doses required to trigger a response and how the organisms deal with the stress. To learn more about the cellular processes, scientists in Switzerland subjected algae to a range of silver concentrations. The results are reassuring, but the presence of other stressors could compound the problem.
Researchers from NIST and the FDA have demonstrated that they can make sensitive chemical analyses of minute samples of nanoparticles by, essentially, roasting them on top of a quartz crystal. The NIST-developed technique, "microscale thermogravimetric analysis," holds promise for studying nanomaterials in biology and the environment, where sample sizes often are quite small and larger-scale analysis won't work.
A light-activated drug delivery system for treating cancer is particularly promising to traditional chemotherapy methods because it can accomplish spatial and temporal control of drug release. To this end, scientists have developed a new type of nanoparticle that can absorb energy from tissue-penetrating light that releases drugs in cancer cells.
A tabletop device invented at Rice Univ. can tell how efficiently a nanoparticle would travel through a well and may provide a wealth of information for oil and gas producers. The device gathers data on how tracers, microscopic particles that can be pumped into and recovered from wells, move through deep rock formations that have been opened by hydraulic fracturing.
The scarcity of ultraviolet (UV) light in sunlight has held back the usefulness of titanium dioxide-based photocatalysts. Through the application of nanotechnology, researchers in Japan have recently succeeded in the development of better titanium dioxide-based material that can be activated by visible light. The solution lies in an array of nanoparticles that “simulate” the photoexcitation of UV light.
Clemson Univ. researchers have developed nanoparticles that can deliver drugs targeting damaged arteries, a non-invasive method to fight heart disease. Heart disease is the leading cause of death in the U.S., according to the Centers for Disease Control and Prevention. One of the standard ways to treat clogged and damaged arteries currently is to implant vascular stents, which hold the vessels open and release such drugs as paclitaxel.
An electrode designed like a pomegranate—with silicon nanoparticles clustered like seeds in a tough carbon rind—overcomes several remaining obstacles to using silicon for a new generation of lithium-ion batteries, say its inventors at Stanford Univ. and the SLAC National Accelerator Laboratory.
Inspired by tiny particles that carry cholesterol through the body, Massachusetts Institute of Technology chemical engineers have designed nanoparticles that can deliver snippets of genetic material that turn off disease-causing genes. This approach, known as RNA interference, holds great promise for treating cancer and other diseases. However, delivering enough RNA to treat the diseased tissue has proven difficult.
A Texas bioengineer has received a four-year, $1.4 million National Institutes of Health grant to create a nanoparticle system to shore up arterial walls following angioplasty and stenting procedures to treat coronary arterial disease. Kytai Nguyen discovered a way to use nanoparticles to help the arteries heal themselves more effectively.