#New absorber will lead to better biosensors Biological sensors or biosensors are like technological canaries in the coalmine.
Currently plasmonic absorbers used in biosensors have a resonant bandwidth of 50 nanometers said Koray Aydin assistant professor of electrical engineering and computer science at Northwestern University's Mccormick School of engineering and Applied science.
Aydin and his team have created a new nanostructure that absorbs a very narrow spectrum of light#having a bandwidth of just 12 nanometers.
By using nanofabrication techniques in the lab Aydin's team found that removing the insulating layer#leaving only metallic nanostructures#caused the structure to absorb a much narrower band of light.
#'Stealth'nanoparticles could improve cancer vaccines Cancer vaccines have emerged recently as a promising approach for killing tumor cells before they spread.
And the key they report in the journal ACS Nano is in the vaccine's unique stealthy nanoparticles.
if stealthy nanoparticles they had developed and clinically tested in patients might hold the answer. The researchers injected the nanoparticles into mice.
They found that the particles which have no electric charge or surface molecules that would attract the attention of circulating immune cells were able to enter the mice's lymph nodes.
When molecules for signaling killer T cells were put inside the nanoparticles they hindered tumor growth far better than existing vaccines.
Nanogel-Based Immunologically Stealth Vaccine Targets Macrophages in the Medulla of Lymph node and Induces Potent Antitumor Immunity ACS Nano 2014 8 (9) pp 9209#9218.
We developed a nanoparticulate cancer vaccine by encapsulating a synthetic long peptide antigen within an immunologically inert nanoparticulate hydrogel (nanogel) of cholesteryl pullulan (CHP.
After subcutaneous injection to mice the nanogel-based vaccine was transported efficiently to the draining lymph node and was engulfed preferentially by medullary macrophages
The nanogel-based vaccine significantly inhibited in vivo tumor growth in the prophylactic and therapeutic settings compared to another vaccine formulation using a conventional delivery system incomplete Freund's adjuvant.
which may underlie the potency of the macrophage-oriented nanogel-based vaccine. These results indicate that targeting medullary macrophages using the immunologically stealth nanoparticulate delivery system is an effective vaccine strategy e
#Nanoparticles accumulate quickly in wetland sediment (Phys. org) A Duke university 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.
The results indicate little risk to humans ingesting the particles through drinking water say scientists at Duke's Center for the Environmental Implications of Nanotechnology (CEINT.
But the researchers warn that based on their previous research the tendency for the nanotubes to accumulate in sediment could indirectly damage the aquatic food chain in the long term
if the nanoparticles provide Trojan horse piggyback rides to other harmful molecules. The results appear online in the journal Environmental science:
Ferguson and his colleagues dosed the mesocosms with single-walled carbon nanotubes and measured their concentrations in the water soil and living organisms during the course of a year.
They found that the vast majority of the nanoparticles quickly accumulated in the sediment on the pond floor.
However they found no sign of nanoparticle buildup in any plants insects or fish living in the mesocosms.
These nanoparticles are really good at latching onto other molecules including many known organic contaminants said Ferguson.
The nanoparticle-pollutant package could then be eaten by sediment-dwelling organisms in a sort of'Trojan horse'effect allowing the adsorbed contaminants to accumulate up the food chain.
Fate of single walled carbon nanotubes in wetland ecosystems. Schierz A. Espinasse B. Wiesner M. R. Bisesi J. H. Sabo-Attwood T. Ferguson P. L. Environmental science:
#All directions are created not equal for nanoscale heat sources Thermal considerations are rapidly becoming one of the most serious design constraints in microelectronics, especially on submicron scale lengths.
a professor of materials science and engineering at Illinois."Our current understanding of nanoscale thermal transport isn't nuanced enough to quantitatively predict
Wilson and Cahill also studied the effect of interfaces on nanoscale thermal transport.""It's been well known for 75 years that the presence of a boundary adds a thermal boundary resistance to the heat-transfer problem,
"Wilson and Cahill also provided a theoretical description of their results that can be used by device engineers to better manage heat and temperature in nanoscale devices c
Their experiments show that future computer chips could be based on three-dimensional arrangements of nanometer scale magnets instead of transistors.
They report their latest results in the journal Nanotechnology. In a 3d stack of nanomagnets, the researchers have implemented a so-called majority logic gate
which could serve as a programmable switch in a digital circuit. They explain the underlying principle with a simple illustration:
Gates made from field-coupled nanomagnets work in an analogous way, with the reversal of polarity representing a switch between Boolean logic states,
of which sits 60 nanometers below the other two, and is read out by a single output magnet.
So-called domain walls generated there are able to flow through magnetic wires under the control of surrounding nanomagnets.
The most basic building blocks, the individual nanomagnets, are comparable in size to individual transistors. Furthermore, where transistors require contacts and wiring,
nanomagnets operate purely with coupling fields. Also, in building CMOS and nanomagnetic devices that have the same function for example
TUM doctoral candidate Irina Eichwald, lead author of the Nanotechnology paper, explains:""The 3d majority gate demonstrates that magnetic computing can be exploited in all three dimensions,
Briseno with colleagues and graduate students at UMASS Amherst and others at Stanford university and Dresden University of Technology Germany report in the current issue of Nano Letters that by using single-crystalline organic nanopillars
or nanograss they found a way to get around dead ends or discontinuous pathways that pose a serious drawback when using blended systems known as bulk heterojunction donor-acceptor or positive-negative (p-n) junctions for harvesting energy in organic solar cells.
We report here that we have developed at last the ideal architecture composed of organic single-crystal vertical nanopillars.
Nanopillars are engineered nanoscale surfaces with billions of organic posts that resemble blades of grass and like grass blades they are particularly effective at converting light to energy.
In this case the anisotropy is along the nanopillar perpendicular to the substrate. Briseno says The biggest challenge in producing this architecture was finding the appropriate substrate that would enable the molecules to stack vertically.
Vertical nanopillars are ideal geometries for getting around these challenges Briseno says because charge separation/collection is most efficient perpendicular to the plastic device.
In this case our nanopillars highly resemble nanograss. Our systems share similar attributes of grass such as high density array system vertical orientations
We envision that our nanopillar solar cells will appeal to low-end energy applications such as gadgets toys sensors and short lifetime disposable devices s
and Center for Nanoscience and Nanotechnology, have been developing sophisticated micro -and nanotechnological toolsanging in size from one millionth to one billionth of a metero develop functional substitutes for damaged heart tissues.
Searching for innovative methods to restore heart function especially cardiac"patches"that could be transplanted into the body to replace damaged heart tissue,
which incorporates biomaterial harvested from patients and gold nanoparticles.""Our goal was said twofold Dr. Dvir.""To engineer tissue that would not trigger an immune response in the patient,
"At his Laboratory for Tissue Engineering and Regenerative medicine, Dr. Dvir explored the integration of gold nanoparticles into cardiac tissue to optimize electrical signaling between cells."
we deposited gold nanoparticles on the surface of our patient-harvested matrix, 'decorating'the biomaterial with conductors,
"The result was that the nonimmunogenic hybrid patch contracted nicely due to the nanoparticles, transferring electrical signals much faster and more efficiently than non-modified scaffolds."
#Nanotube cathode beats large pricey laser Scientists are a step closer to building an intense electron beam source without a laser.
Using the High-Brightness Electron Source Lab at DOE's Fermi National Accelerator Laboratory a team led by scientist Luigi Faillace of Radiabeam Technologies is testing a carbon nanotube cathode about the size of a nickel
Tests with the nanotube cathode have produced beam currents a thousand to a million times greater than the one generated with a large pricey laser system.
While carbon nanotube cathodes have been studied extensively in academia Fermilab is the first facility to test the technology within a full-scale setting.
but at the nanoscale it resembles in Piot's words millions of lightning rods. When a strong electric field is applied it pulls streams of electrons off the surface of the cathode creating the electron beam.
The tested nanotube cathode requires no laser: it only needs the electric field already generated by an accelerator to siphon the electrons off a process dubbed field emission n
#Nanoengineering enhances charge transport promises more efficient future solar cells Solar cells based on semiconducting composite plastics and carbon nanotubes is one of the most promising novel technology for producing inexpensive printed solar cells.
This is achieved thanks to clever nanoengineering of the active layer inside the device. Their results are published as front page news in the journal Nanoscale.
Carbon nanotubes are more and more attractive for use in solar cells as a replacement for silicon. They can be mixed in a semiconducting polymer
and the nanotubes have outstanding electrical conductivity, and they can effectively separate and transport electrical charges generated from solar energy.
and charge transport at very low nanotube loadings, thereby strongly reducing materials costs o
#Scientists improve microscopic batteries with homebuilt imaging analysis (Phys. org) In a rare case of having their cake
To see as much detail as possible the team decided to use a set of electron detectors to collect electrons in a wide range of scattering angles an arrangement that gave them plenty of structural information to assemble a clear picture of the battery's interior down to the nanoscale level.
Miniature all-solid-state heterostructure nanowire Li-ion batteries as a tool for engineering and structural diagnostics of nanoscale electrochemical processes.
Nanoscale DOI: 0. 1039/c4nr01666a Aug 15 2014
#Research mimics brain cells to boost memory power RMIT University researchers have brought ultra-fast, nanoscale data storage within striking reach,
using technology that mimics the human brain. The researchers have built a novel nanostructure that offers a new platform for the development of highly stable and reliable nanoscale memory devices.
The pioneering work will feature on a forthcoming cover of materials science journal Advanced Functional Materials (11 november.
Project leader Dr Sharath Sriram, co-leader of the RMIT Functional Materials and Microsystems Research Group, said the nanometer-thin stacked structure was created using thin film, a functional oxide
"The structure we developed could be used for a range of electronic applications from ultrafast memory devices that can be shrunk down to a few nanometers,
#New research points to graphene as a flexible low-cost touchscreen solution New research published today in the journal Advanced Functional Materials suggests that graphene-treated nanowires could soon replace current touchscreen technology
Researchers from the University of Surrey and AMBER the materials science centre based at Trinity college Dublin have demonstrated now how graphene-treated nanowires can be used to produce flexible touchscreens at a fraction of the current cost.
Using a simple scalable and inexpensive method the researchers produced hybrid electrodes the building blocks of touchscreen technology from silver nanowires and graphene.
Lead author Dr Izabela Jurewicz from the University of Surrey commented Our work has cut the amount of expensive nanowires required to build such touchscreens by more than fifty times as well as simplifying the production process.
Conductive nanofiber networks for flexible unbreakable and transparent electrode e
#Harnessing an unusual'valley'quantum property of electrons Yoshihiro Iwasa and colleagues from the RIKEN Center for Emergent Matter Science the University of Tokyo and Hiroshima University have discovered that ultrathin films of a semiconducting material have properties that form the basis for a new kind of low-power electronics
In the form of nanowires and nanoparticles it has particular potential for use in the manufacture of solar cells
It had already been demonstrated on nanowires made from one crystalline form of gallium arsenide the cubic so-called zincblende structure that the band gap widens under pressure.
The present research focused instead on nanowires of a less-common crystalline form the hexagonal so-called wurtzite structure.
They discovered the band gap that the electrons need to leap across to also widened although not as much as in the case of the zincblende crystal nanowires.
Significantly they discovered that around 207000 times normal atmospheric pressure (21 gigapascals) the wurtzite gallium arsenide nanowires underwent a structural change that induced a new phase the so-called orthorhombic one
or even a single nanowire and realize much more complex and useful electronic functions through interactions across the phases Goncharov said.
#Controlling photoluminescence with silicon nanophotonics for better devices Silicon nanowires have a great deal of potential in future high-performance electronic sensing and energy devices.
Red photoluminescence has been reported in silicon nanowires but for many applications this hampers device performance. As Tsuyoshi Okuno from the University of Electro-Communications and his colleagues point out in a recent report
Okuno and his colleagues fabricated silicon nanowire arrays by metal-assisted chemical etching an approach that is simple and cost-effective.
They deposited metal nanoparticles on a silicon wafer and etched nanowires using aqueous H2o2. Although the researchers did not have precise control over the nanowire morphology they did observe that higher concentrations of H2o2 led to thicker nanowires.
Photoluminescence studies did not reveal a link between photoluminescence and nanowire diameter or length alone but low aspect ratio nanowires exhibited red photoluminescence.
Further observations of the morphology identified silicon nanocrystals at the nanowire ends which was corroborated by Raman studies of single nanowires.
These nanocrystals disappear on annealing as does the red photoluminescence. The researchers attribute the red photoluminescence to defect states between nanocrystals and surrounding oxide and excitonic transitions.
As the researchers conclude in their report These results of Si nanowire arrays are believed to be useful for future optoelectronic and photovoltaic applications.
Explore further: Mixing silicon with other materials improves the diversity of nanoscale electronic devices More information:
Oda K. Nanai Y. Sato T. Kimura S. & Okuno T. Correlation between photoluminescence and structure in silicon nanowires fabricated by metal-assisted etching.
Physica Status Solidi A 211 (4) 848-855 (2014) DOI: 10.1002/pssa. 20133016 6
#World's smallest reference material is big plus for nanotechnology If it's true that good things come in small packages,
then the National Institute of Standards and Technology (NIST) can now make anyone working with nanoparticles very happy.
NIST recently issued Reference Material (RM) 8027, the smallest known reference material ever created for validating measurements of these man-made, ultrafine particles between 1 and 100 nanometers (billionths of a meter) in size.
RM 8027 consists of five hermetically sealed ampoules containing one milliliter of silicon nanoparticlesll certified to be close to 2 nanometers in diameteruspended in toluene.
To yield the appropriate sizes for the new RM the nanocrystals are etched from a silicon wafer,
separated using ultrasound and then stabilized within an organic shell. Particle size and chemical composition are determined by dynamic light scattering, analytical centrifugation, electron microscopy and inductively coupled plasma mass spectrometry (ICP-MS),
a powerful technique that can measure elements at concentrations as low as several parts per billion."
"For anyone working with nanomaterials at dimensions 5 nanometers or less, our well-characterized nanoparticles can ensure confidence that their measurements are accurate,
"says NIST research chemist Vytas Reipa, leader of the team that developed and qualified RM 8027.
Silicon nanoparticles such as those in RM 8027 are being studied as alternative semiconductor materials for next-generation photovoltaic solar cells and solid-state lighting,
Another potential application comes from the fact that silicon crystals at dimensions of 5 nanometers
silicon nanoparticles may one day serve as easily detectable"tags"for tracking nanosized substances in biological, environmental or other dynamic systems s
We exploit the'self-organization'of semiconducting nanocrystals by the'Stranski-Krasnov (SK) mode of crystal growth for producing ordered highly dense
or'top-down'methods widely used for the fabrication of nanostructures. Notably electrons in quantum dot structures are confined inside nanometer sized three dimension boxes.
Novel applications of'quantum dots'including lasers biological markers qubits for quantum computing and photovoltaic devices arise from the unique optoelectronic properties of the QDS
This density was one of the critical advances for achieving high efficiency quantum dot based photovoltaic devices says Yamaguchi.
dx. doi. org/10.1143/APEX. 5. 125502 Katsuyoshi Sakamoto Yasunori Kondo Keisuke Uchida and Koichi Yamaguchi Quantum dot density dependence of power conversion
Polymersome magneto-valves for reversible capture and release of nanoparticles. Nature Communications DOI: 10.1038/ncomms601 6
#Fabrication route improves the properties of aluminum-based nanocomposites One challenge in producing strong elastic
and hard-wearing nanocomposites is obtaining an even distribution of the nanoparticles in the metal matrix.
Their technique is a viable new method for manufacturing nanocomposites and has exciting potential for the car space and defense industries.
They then injected a slurry of aluminum oxide nanoparticles into the holes and heated the sheet in an oven.
Placing the nanoparticles in the sheet prior to the friction stir processing step significantly increased the concentration of nanoparticles in the composite.
The team used scanning electron microscopy to check two key properties that influence the strength of nanocomposites.
They first demonstrated that the nanoparticles were dispersed uniformly which means the material has no weak points.
and without the Al2o3 nanoparticles the team showed that the nanoparticles contributed to the reduction in grain size.
The best nanoparticle distribution and smallest aluminum alloy grains were obtained after passing the rotating tool through the sheet four times.
We plan to continue this research to further improve the mechanical and thermal properties as well as the wear resistance of the nanocomposites says Guo.
Scientists use nanoparticles to control growth of materials More information: Guo J. F. Liu J. Sun C. N. Maleksaeedi S. Bi G. et al.
#Gold nanoparticles linked to single stranded-dna DNA create a simple but versatile genetic testing kit Tests for identifying genetic variations among individuals
and elegant nanoprobe for assessing sensitivity to the drug warfarin. To develop the nanoprobe Jackie Ying at the A*STAR Institute of Bioengineering
and Nanotechnology and co-workers in Singapore Taiwan and Japan devised a relatively simple procedure that uses standard laboratory equipment
and can be adapted easily for other genetic tests. Our method is faster more cost-effective
The researchers used gold nanoparticles attached to short sections of DNA that bind to specific complementary sequences of DNA through the base pairing that holds together double-stranded DNA.
These nanoprobes were exposed to fragments of DNA that had been cut out and amplified from a patient's genome.
The nanoprobes are initially pink due to surface plasmonic effects involving ripples of electric charge. When analyzed if the probes do not bind to the DNA fragments they aggregate
Using gold nanoprobes to unlock your genetic profile More information: Zu Y. Tan M.-H. Chowbay B. Lee S. C. Yap H. et al.
Nanoprobe-based genetic testing. Nano Today 9 166#171 (2014. dx. doi. org/10.1016/j. nantod. 2014.04.00
#Researchers uncover properties in nanocomposite oxide ceramics for reactor fuel Nanocomposite oxide ceramics have potential uses as ferroelectrics fast ion conductors
In a nanocomposite the size of each of these grains is on the order of nanometers roughly 1000 times smaller than the width of a human hair.
and radiation damage resistance of oxide nanocomposites by controlling the termination chemistry at the interface.
We believe that this discovery that the interface structure is sensitive to the chemistry of the interface will open the door for new research directions in oxide nanocomposites said Blas Uberuaga lead researcher on the effort.
Gan microstructures and nanostructures are garnering attention within the research community as light-emitting devices because of their variable-color light emission
#Experts create unique nanoparticles for aerospace industry A development of three universities enables improved thermal and electronic properties on devices with nickel-titanium alloys.
Experts collaborated to produce nanoparticles made of a titanium-nickel alloy used in the development of thermal and electrical sensors that control the operation of high-tech devices such as those used in aerospace,
Meanwhile, the team at the UANL manufactured nanoparticles used in the sensors, and after a series of tests confirmed the effectiveness of the titanium-nickel as an electrical and thermal conductor.
With nanoparticles, they produced temperature-sensitive devices that transmit electrical energy to the system but do not cause overheating.
Then nanoparticles were obtained by thermal evaporation techniques where the molecular bonds of the metals degraded as a powder
Besides generating nanoparticles for sensors, another goal of this proyect is to train high level human resources in the areas of metallurgy alloys with shape memory,
nanotechnology and improving infrastructure in order to impact scientific and technological production in both countries. Finally, to test the effectiveness of the material,
and related materials rather than just microscopic flakes as previously was the case greatly expands their promise for nanoelectronic and optoelectronic applications.
Dr Huang and his team published their findings in the latest issue of the journal Nanoscale.
#Nanotubes help healing hearts keep the beat (Phys. org) Carbon nanotubes serve as bridges that allow electrical signals to pass unhindered through new pediatric heart-defect patches invented at Rice university and Texas Children's Hospital.
and chemical engineer and chemist Matteo Pasquali created the patches infused with conductive single-walled carbon nanotubes.
The nanotubes overcome a limitation of current patches in which pore walls hinder the transfer of electrical signals between cardiomyocytes the heart muscle's beating cells
Nanotubes can fix that and Jacot who has a joint appointment at Rice and Texas Children's took advantage of the surrounding collaborative research environment.
We thought nanotubes could be integrated easily. Nanotubes enhance the electrical coupling between cells that invade the patch helping them keep up with the heart's steady beat.
When cells first populate a patch their connections are compared immature with native tissue Jacot said.
but the nanotubes forge a path around the obstacles. Jacot said the relatively low concentration of nanotubes 67 parts per million in the patches that tested best is key.
Earlier attempts to use nanotubes in heart patches employed much higher quantities and different methods of dispersing them.
Jacot's lab found a component they were already using in their patches#chitosan#keeps the nanotubes spread out.
Chitosan is amphiphilic meaning it has hydrophobic and hydrophilic portions so it can associate with nanotubes (which are hydrophobic)
and keep them from clumping. That's what allows us to use much lower concentrations than others have tried.
and get to it with the fewest nanotubes possible he said. We can do this if we control dispersion well and use high-quality nanotubes.
The patches start as a liquid. When nanotubes are added the mixture is shaken through sonication to disperse the tubes
which would otherwise clump due to Van der waals attraction. Clumping may have been an issue for experiments that used higher nanotube concentrations Pasquali said.
The material is spun in a centrifuge to eliminate stray clumps and formed into thin fingernail-sized discs with a biodegradable polycaprolactone backbone that allows the patch to be sutured into place.
As a side benefit nanotubes also make the patches stronger and lower their tendency to swell
Pasquali noted that Rice's nanotechnology expertise and Texas Medical center membership offers great synergy. This is a good example of how it's much better for an application person like Dr. Jacot to work with experts who know how to handle nanotubes rather than trying to go solo as many do said he.
We end up with a much better control of the material. The converse is also true of course
Biocompatible Carbon nanotube#Chitosan Cardiac Scaffold Matching the Electrical conductivity of the Heart. Seokwon Pok Flavia Vitale Shannon L. Eichmann Omar M. Benavides Matteo Pasquali and Jeffrey G Jacot ACS Nano Just Accepted Manuscript DOI:
Using an optical microstructure and gold nanoparticles, they have amplified the interaction of light with DNA to the extent that they can now track interactions between individual DNA molecule segments.
and gold nanowires approx. 12 nanometres in diameter and 42 nanometres in length. The gold wire is therefore only about one ten-thousandth the thickness of a hair.
The microsphere and nanowire amplify the interaction between light and molecules. With the help of a prism, the researchers shine laser light into the microsphere.
Vollmer and his colleagues therefore fix a nanowire to the surface of the glass bead.
to the nanowire mounted on the microsphere. When a matching, i e. COMPLEMENTARY DNA fragment binds to the"bait"on the nanowire
the wavelength of the light shifts and is amplified by the microsphere and nanowire. This shift can be measured.
Different strand sections can be distinguished by their binding behaviour However, the physicists used a shorter DNA fragment than is usual in similar procedures.
#Engineers show light can play seesaw at the nanoscale University of Minnesota electrical engineering researchers have developed a unique nanoscale device that for the first time demonstrates mechanical transportation of light.
and will appear in the October issue of Nature Nanotechnology researchers developed a novel nanoscale device that can capture measure
Optomechanical photon shuttling between photonic cavities Nature Nanotechnology (2014) DOI: 10.1038/nnano. 2014.20 0
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