Thanks to the EU-funded research project called NANOANTENNA completed in March 2013, physicists joined forces with chemists,
nanotechnologists and biomedical researchers with the aim of developing a so-called plasmonic nanobiosensor for the detection of proteins.
It consisted of nanoantennas, tiny gold rods about 100 to 200 nanometres long and 60 to 80 nm wide.
By shining light onto such a nanoantenna, the electrons inside start moving back and forth, amplifying the light radiation in hot spots regions of the antenna,
If these molecules are close to nanoparticles, the plasmons in the nanoparticles enhance the Raman signal coming from the molecules that have to be detected with several orders of magnitude.
The nanoantennas developed in this project only enhance the emitted Raman signal if the biomolecules are close to the hot spots Therefore,
the molecules have to be trapped to be detected. To do so, the researchers attached bioreceptors, fragments of DNA engineered to recognise specific proteins, to the nanoantennas.
When the nanoantennas studded with the bioreceptors are incubated in a solution that contains the biomarkers to be detected,
the latter become attached to the nanoantennas. When, subsequently, these nanoantennas are illuminated with light, they show the Raman fingerprints of both the bioreceptor and the biomarker,
as Gucciardi points out. One expert comments that health-care programmes are quickly moving to prevention
and early detection of diseases, done in point-of-care (POC) or bed-side conditions."
"says Alexandre Brolo, professor of chemistry specialised in nanotechnology research, who has been developing plasmonic biosensors at the University of Victoria, British columbia, Canada.
"says Maria Carmen Estévez, a researcher at the Catalan Institute of Nanoscience and Nanotechnology in Bellaterra, Spain.
One possibility is to use hybrid solar cells that combine silicon nanowires with low-cost, photoresponsive polymers. The high surface area and confined nature of nanowires allows them to trap significant amounts of light for solar cell operations.
Unfortunately, these thin, needle-like structures are very fragile and tend to stick together when the wires become too long.
Now, findings by Xincai Wang from the A*STAR Singapore Institute of Manufacturing Technology and co-workers from Nanyang Technological University could turn the tables on silicon nanowires by improving the manufacturing of silicon'nanoholes'arrow cavities carved into silicon wafers
Nanoholes are particularly effective at capturing light because photons can ricochet many times inside these openings until absorption occurs.
One significant problem, notes Wang, is control of the initial stages of nanohole formation crucial period that can often induce defects into the solar cell.
'maskless'approach to producing nanoholes using silver nanoparticles. First, they deposited a nanometer-thin layer of silver onto a silicon wafer
which they toughened by annealing it using a rapid-burst ultraviolet laser. Careful optimization of this procedure yielded regular arrays of silver nanospheres on top of the silicon surface,
with sphere size and distribution controlled by the laser annealing conditions. Next, the nanosphereilicon complex was immersed into a solution of hydrogen peroxide and hydrofluoric acid mixture that eats away at silicon atoms directly underneath the catalytic silver nanospheres.
Subsequent removal of the silver particles with acid produced the final, nanohole-infused silicon surface (see image).
The team analyzed the solar cell activity of their nanohole interfaces by coating them with a semiconducting polymer and metal electrodes.
Their experiments revealed a remarkable dependence on nanohole depth: cavities deeper than one micrometer showed sharp drops in power conversion efficiency from a maximum of 8. 3 per cent due to light scattering off of rougher surfaces and higher series resistance effects."
"Our simple process for making hybrid silicon nanohole devices can successfully reduce the fabrication costs
which impede the solar cell industry, "says Wang.""In addition, this approach can be transferred easily to silicon thin films to develop thin-film siliconolymer hybrid solar cells with even higher efficiency. e
In recognition of the innovative approach the research was introduced on the cover of Nanoscale a high impacting peer-reviewed journal in the field of nano science.
along with Dr. Seok-In Na at Chonbuk National University and Dr. Byoung Gak Kim at KRICT synthesized carbon nanosheets similar to graphene using polymer
The research outcome was introduced in Nanoscale a journal of Royal Society of Chemistry in the UK under the title of One-step Synthesis of Carbon Nanosheets Converted from a Polycylic Compound
The research team developed carbon nanosheet in a two-step process which consists of coating the substrate with a plymer solution and heating.
The carbon nanosheet can be mass-produced in a simpler process while having high quality since the new process bypasses the steps that are prone to formation of defects such as elimination of the metal substrate or transfer of graphene to another board.
#Shrinky Dinks close the gap for nanowires How do you put a puzzle together when the pieces are too tiny to pick up?
to close the gap between nanowires in an array to make them useful for high-performance electronics applications.
Nanowires are extremely fast, efficient semiconductors, but to be useful for electronics applications, they need to be packed together in dense arrays.
Researchers have struggled to find a way to put large numbers of nanowires together so that they are aligned in the same direction and only one layer thick."
"Chemists have done already a brilliant job in making nanowires exhibit very high performance. We just don't have a way to put them into a material that we can handle,
people can make nanowires and nanotubes using any method they like and use the shrinking action to compact them into a higher density."
"The researchers place the nanowires on the Shrinky Dinks plastic as they would for any other substrate,
but then shrink it to bring the wires much closer together. This allows them to create very dense arrays of nanowires in a simple, flexible and very controllable way.
The shrinking method has added the bonus of bringing the nanowires into alignment as they increase in density.
Nam's group demonstrated how even wires more than 30 degrees off-kilter can be brought into perfect alignment with their neighbors after shrinking."
Nam first had the idea for using Shrinky Dinks plastic to assemble nanomaterials after seeing a microfluidics device that used channels made of shrinking plastic.
and the low cost of plastic could have a huge impact on nanowire assembly and processing for applications."
"I'm interested in this concept of synthesizing new materials that are assembled from nanoscale building blocks, "Nam said."
For example, experiments have shown that film made of packed nanowires has properties that differ quite a bit from a crystal thin film."
made of densely packed nanowires, that could harvest energy from light much more efficiently than traditional thin-film solar cells s
Lots of pores for sulfur The chemists Professor Thomas Bein (LMU), Coordinator of the Energy conversion Division of the Nanosystems Initiative Munich, Professor Linda Nazar (University of Waterloo, Waterloo Institute
of Nanotechology) and their colleagues have succeeded now in producing a novel type of nanofiber whose highly ordered and porous structure gives it an extraordinarily high surface-to-volume ratio.
#Chirality-controlled growth of single-walled carbon nanotubes Recently, Professor Li Yan's research team developed a novel strategy to produce single-walled carbon nanotubes with specific chirality by applying a new family of catalysts,
who also serves the president of Fullerene, Carbon nanotubes, and Graphene research Society of Japan. Single-walled carbon nanotube (SWNT
which can be considered as a seamlesscylinder formed by rolling a piece of graphene, may be either metallic
SWNTS has shown great potential in various fields such as nanoelectronics. In 2009, the International Technology Roadmap for Semiconductors (ITRS) selected carbon-based nanoelectronics to include carbon nanotubes
and graphene for additional resources and detailed road mapping for ITRS as promising technologies targeting commercial demonstration in the next 10-15 year horizon.
As stated by Dr. Avouris in his review article published in Nature Nanotechnology (V. 2 P. 605"
the main hurdle (of carbon-based electronics) is our current inability to produce large amounts of identical nanostructureshere is no reliable way to directly produce a single CNT type such as will be needed in a large integrated system."
The catalysts, tungsten-based bimetallic alloy nanoparticles of non-cubic symmetry, have high melting points and consequently are able to maintain their crystal structure during the chemical vapor deposition (CVD) process,
Experimental evidence and theoretical simulation reveal that the good structural match between the carbon atom arrangement around the nanotube circumference
and the arrangement of the atoms in one of the planes of the nanocrystal catalyst facilitates the (n,
This method is also valid for other tungsten-based alloy nanocatalysts to grow SWNTS of various designed chirality."
"Employing tungsten-based alloy nanocrystals with unique structure as catalysts paves a way for the ultimate chirality control in SWNT growth.
carbon-based nanoelectronics",said Li. The work was evaluated highly by Professor Jie Liu at Duke university,
"The chirality-specific growth of single-walled carbon nanotubes is the most challenging and important issue in the field,
especially nanoelectronics. c
#Lab unzips nanotubes into ribbons by shooting them at a target (Phys. org) Carbon nanotubes unzipped into graphene nanoribbons by a chemical process invented at Rice university are finding use in all kinds of projects
but Rice scientists have now found a chemical-free way to unzip them. The Rice lab of materials scientist Pulickel Ajayan discovered that nanotubes that hit a target end first turn into mostly ragged clumps of atoms.
But nanotubes that happen to broadside the target unzip into handy ribbons that can be used in composite materials for strength
and applications that take advantage of their desirable electrical properties. The Rice researchers led by graduate student Sehmus Ozden reported their finding in the American Chemical Society journal Nano Letters.
The researchers fired pellets of randomly oriented multiwalled carbon nanotubes from a light gas gun built by the Rice lab of materials scientist Enrique Barrera with funding from NASA.
When they inspected the resulting carbon rubble they found nanotubes that smashed into the target end first
or at a sharp angle simply deformed into a crumpled nanotube. But tubes that hit lengthwise actually split into ribbons with ragged edges.
Single-wall nanotubes do just the opposite; when the tube flattens the bottom wall hits the inside of the top wall
Ozden explained that the even distribution of stress along the belly-flopping nanotube which is many times longer than it is wide breaks carbon bonds in a line nearly simultaneously.
The researchers said 70 to 80 percent of the nanotubes in a pellet unzip to one degree or another.
Ozden said the process eliminates the need to clean chemical residues from nanoribbons produced through current techniques.
#Diamond plates create nanostructures through pressure not chemistry You wouldn't think that mechanical forcehe simple kind used to eject unruly patrons from bars,
or emboss the raised numerals on credit cardsould process nanoparticles more subtly than the most advanced chemistry.
and original method uses simple pressure kind of high-tech embossingo produce finer and cleaner results in forming silver nanostructures than do chemical methods,
when applied to nanoparticle arrays, forms new nanostructures with tunable properties.""There is a great potential market for this technology,
The pressure, delivered by two diamond plates tightened by four screws to any controlled setting, shepherds silver nanospheres into any desired volume.
Propinquity creates conditions that produce nanorods, nanowires and nanosheets at chosen thicknesses and lengths rather than the one-size-fits-all output of a chemical process, with no environmentally harmful residues.
While experiments reported in the paper were performed with silverhe most desirable metal because it is the most conductive,
platinum and other metallic nanoparticles Clem said the researchers are now starting to work with semiconductors.
A coating of nanoparticles that can build into another structure has a certain functionality we don't have right now.
For example, under pressure, the dimensions of ordered three-dimensional nanoparticle arrays shrink. By fabricating a structure in
the nanoparticle array will remain at a constant state, able to transmit light and electricity with specific characteristics.
At even higher pressures, nanoparticles are forced to sinter, or bond, forming new classes of chemically
and mechanically stable nanostructures that no longer need restraining surfaces. These cannot be manufactured using current chemical methods.
composition and phase orientation of the initial nanoparticle arrays, a variety of nanostructures or nanocomposites and 3-D interconnected networks are achievable.
#Eco-friendly versatile nanocapsules developed The Institute for Basic Science (IBS) has announced that the Centre for Self-assembly
and Complexity have succeeded in developing a new technology that introduces metal nanoparticles on the surface of polymer nanocapsules made of cucurbit 6 uril.
The researchers have found that using polymer nanocapsules made of cucurbit 6 uril and metal salts can serve as a versatile platform where equal sized metal nanoparticles can be distributed evenly on the surface of the polymer nanocapsules.
Cucurbit 6 uril has properties which strongly and selectively recognize organic and inorganic chemical species. This makes it possible to use it as a protecting agent
which can stabilize metal nanoparticles by preventing them from clustering together. The metal nanoparticle-decorated polymer nanocapsules exhibit the following properties in water:
high stability for up to 6 months; high dispersibility; excellent catalytic activity; and reusability in carbon-carbon and carbon-nitrogen bond-forming reactions with 100%conversion efficiency.
Even though metal nanoparticles are used variously in industrial, pharmaceutical and agricultural (fertilizer) applications as a catalyst, toxic liquids such as toluene and hexane are used usually as solvents in the carbon-carbon
and carbon-nitrogen bond-forming reactions. These toxic liquid solvents raise many issues for concern including environmental pollution, high cost of disposal, health problems and poisoning during the disposal process.
However, this new technology is able to replace those toxic liquids as it allows carbon-carbon and carbon-nitrogen bond-formation with the use of metal nanoparticles as a catalyst
"The research results demonstrated that this new technology shows high stability, dispersibility, catalytic activity, and reusability in water, which other existing metal nanoparticles on solid supports have not been able to do,
"says Kimoon Kim, director of the Center for Self-assembly and Complexity at IBS.""It is important as it presents new possible applications in green solvents or bioimaging and nanomedicine fields
#Scientists develop a'nanosubmarine'that delivers complementary molecules inside cells With the continuing need for very small devices in therapeutic applications there is a growing demand for the development of nanoparticles that can transport
and deliver drugs to target cells in the human body. Recently researchers created nanoparticles that under the right conditions self-assemble trapping complementary guest molecules within their structure.
Like tiny submarines these versatile nanocarriers can navigate in the watery environment surrounding cells and transport their guest molecules through the membrane of living cells to sequentially deliver their cargo.
Although the transport of molecules inside cells with nanoparticles has been achieved previously using various methods researchers have developed nanoparticles capable of delivering
and exchanging complementary molecules. For practical applications these nanocarriers are highly desirable explains Francisco Raymo professor of chemistry in the University of Miami College of Arts and Sciences and lead investigator of this project.
The ability to deliver distinct species inside cells independently and force them to interact exclusively in the intracellular environment can evolve into a valuable strategy to activate drugs inside cells Raymo says.
The new nanocarriers are15 nanometers in diameter. They are made supramolecular constructs up of building blocks called amphiphilic polymers.
These nanocarriers hold the guest molecules within the confines of their water-insoluble interior and use their water-soluble exterior to travel through an aqueous environment.
As a result these nanovehicles are ideal for transferring molecules that would otherwise be insoluble in water across a liquid environment.
if the nanoparticles can actually travel through the bloodstream. That would be the dream but we have no evidence that they can actually do so Raymo says.
The size of these nanoparticles their dynamic character and the fact that the reactions take place under normal biological conditions (at ambient temperature
and neutral environment) makes these nanoparticles an ideal vehicle for the controlled activation of therapeutics directly inside the cells Raymo says.
#Smart gating nanochannels for confined water developed Confined water exists widely and plays important roles in natural environments, particularly inside biological nanochannels.
Professor Lei Jiang and his group from State Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, set out to study this unified bionic frontier.
After several years of innovative research, they developed a series of biomimetic nanochannels, delivered a strategy for the design
and construction of smart nanochannels and applied the nanochannels in energy conversion systems. The author thought the inner surface property was the base for confined transportation.
entitled"Construction of biomimetic smart nanochannels for confined water",was published in National Science Review. Nature has inspired always greatly technology, engineering and significant inventions.
For example, the lotus can realize the self-cleaning effect using its micro/nanocomposite structure. The water striders can walk easily
and freely on the water surface via the special micro-and nanostructure on their legs.
Recently, Jiang's group focused on the confined water in one dimensional nanostructure materials. The study examined the confined water on the outer surfaces of one dimensional nano-structured materials including spider silk and cactus thorn,
They also studied confined water existing in nanochannel, which included the construction and application of bio-inspired nanochannels.
In this review Prof. Jiang expatiated the confined water that exists in one-dimensional micro/nano composite structures in detail, particularly inside biological nanochannels.
Using these nanochannels as inspiration, they provided a strategy for the design and construction of biomimetic smart nanochannels.
Importantly, they have applied the abiotic analogs to energy conversion systems. The confined water, that is water confined in micro-or mesopores,
not only plays an important role in maintaining the existence and development of living organisms, but also concerns the sustainable development of human society.
and cactus thorn showed the confined water collection on these one dimensional nanostructures was helpful in solving the shortage of freshwater resources.
biological ion channels played key roles for high efficient energy conversion in organisms due to its nanoscale effect and ion selectivity.
much effort has been directed toward building the functional unit with nanometer multistage, multiple scale, asymmetric structure, and so on,
#Bacterial nanometric amorphous Fe-based oxide as lithium-ion battery anode material Leptothrix ochracea is a species of iron-oxidizing bacteria that exists in natural hydrospheres where groundwater outwells worldwide.
and easily-handled electrode material since its basic texture is composed of nanometric particles. The charge-discharge properties of simple L-BIOX/Li-metal cells were examined at current rates of 33. 3ma/g (0. 05c)
Notably the presence of minor components of Si and P in the original L-BIOX nanometric particles resulted in specific and well-defined electrode architecture.
Research and applications of iron oxide nanoparticles More information: Bacterial Nanometric Amorphous Fe-Based Oxide: A Potential Lithium-Ion Battery Anode Material.
Hideki Hashimoto Genki Kobayashi Ryo Sakuma Tatsuo Fujii Naoaki Hayashi Tomoko Suzuki Ryoji Kanno Mikio Takano and Jun Takada.
#Nanoparticles could provide easier route for cell therapy UT Arlington physics researchers may have developed a way to use laser technology to deliver drug and gene therapy at the cellular level without damaging surrounding tissue.
the team paired crystalline magnetic carbon nanoparticles and continuous wave near-infrared laser beams for in
and Mohanty used a 50 to 100 milliwatt laser and the same carbon nanoparticle, which absorbs the beam,
continuous wave near-infrared laser and the nanoparticle to permeate the cell membrane without killing the cells.
whose lab created the study's crystalline magnetic carbon nanoparticle using an electric plasma discharge inside a toulene solution.
A significant advantage of the new method is that the near-infrared light absorption of the nanoparticle can be used to selectively amplify interaction of low power laser with targeted tissue
The magnetic properties of the nanoparticles also mean they can be localized with an external magnetic field;
"Carbon nanoparticles produced for the cancer study varied from five to 20 nanometers wide. A human hair is about 100,000 nanometers wide.
The magnetic carbon nanoparticles also are fluorescent. So, they can be used to enhance contrast of optical imaging of tumors along with that of MRI I
#Metal particles in solids aren't as fixed as they seem memristor study shows In work that unmasks some of the magic behind memristors and"resistive random access memory,
They observed the metal atoms becoming charged ions, clustering with up to thousands of others into metal nanoparticles,
when you shoot multiwalled carbon nanotubes (MWCNTS) out of a gun onto an aluminum target at a velocity of more than 15000 mph?
If a nanotube reaches the target at a 90â°angle (head-on) it will break and deform quite drastically.
However if it is parallel to the target upon impact the nanotube will unzip resulting in a 2d graphene nanoribbon.
since previous simulations have shown that nanotubes break into pieces when subjected to large mechanical forces. Researchers Sehmus Ozden et al. at Rice university in Houston Texas US;
and the Indian Institute of Science in Bangalore India have published a paper on the results of their high-impact nanotube collision experiments in a recent issue of Nano Letters.
Because it was not possible to directly observe the impact due to the nanotubes'small size
and high speed the researchers analyzed the differences in the nanotubes using a transmission electron microscope before and after the impact to extract useful information about
Although each bundle of nanotubes (the pellet) was shot perpendicular to the target the individual randomly aligned nanotubes impacted the target at different angles.
At a 90â°impact angle the nanotubes deformed along the radial direction essentially being smashed like the front of a car in a head-on collision.
At a 45â°impact angle the nanotubes became partly deformed and partly unzipped. At a 0â°angle the nanotubes were unzipped completely
when shot at the aluminum target. The researchers explain that the unzipping occurs on the scale of femtoseconds.
In that short time many atoms along the side of the nanotube become stressed due to the impact resulting in the breaking of the carbon bonds in a straight line along the side of the nanotube.
Many of these atoms ended up being ejected from the nanotube rather than having their bonds neatly broken as in the 0â°impact angle scenario.
Unzipping carbon nanotubes to create 2d graphene nanoribbons is very useful in nanoscience but until now it has typically been achieved with chemical contaminants that leave back contaminants.
By demonstrating for the first time that nanotubes can be unzipped quickly through mechanical means the new study offers a clean-cut a clean chemical-free way to produce high-quality graphene nanoribbons.
As the researchers explained graphene nanoribbons have certain advantages over both nanotubes and graphene that make them attractive for applications.
but making a nanometer scale narrow stripe of it opens the bandgap because of quantum confinement so it is a semiconductor.
Hybrid nanotube-graphene material promises to simplify manufacturing More information: Sehmus Ozden et al. Unzipping Carbon nanotubes at High Impact.
Adding silver nanorods to the graphene film would increase the conductivity to the same as copper,
The design is based on the use of microlattices with nanoscale features, combining great stiffness and strength with ultralow density,
#New approach may be key to quantum dot solar cells with real gains in efficiency (Phys. org) Los alamos researchers have demonstrated an almost fourfold boost of the carrier multiplication yield with nanoengineered quantum dots.
Quantum dots are novel nanostructures that can become the basis of the next generation of solar cells capable of squeezing additional electricity out of the extra energy of blue and ultraviolet photons.
A new study conducted within the Center for Advanced Solar Photophysics demonstrates that appropriately engineered core/shell nanostructures made of lead selenide
and should be realizable with other combinations of materials and/or nanostructure geometries. Jeff Pietryga lead CASP chemist says Further enhancement in carrier multiplication should be possible by combining this new approach with other demonstrated means for increasing multicarrier yields such as by using shape-control
(as in nanorods) and/or materials in which cooling is already naturally slower like Pbte.
Applied together these strategies might provide a practical route to nanostructures exhibiting carrier multiplication performance approaching the limits imposed by energy conservation n
researchers from the USC Viterbi School of engineering describe how they have overcome a major issue in carbon nanotube technology by developing a flexible,
energy-efficient hybrid circuit combining carbon nanotube thin film transistors with other thin film transistors. This hybrid could take the place of silicon as the traditional transistor material used in electronic chips,
and Jialu Zhang developed this energy-efficient circuit by integrating carbon nanotube (CNT) thin film transistors (TFT) with thin film transistors comprised of indium, gallium and zinc oxide (IGZO)."
Instead of working so hard to force nanotubes to do something that they are not good for,
This hybridization of carbon nanotube thin films and IGZO thin films was achieved by combining their types, p-type and n-type, respectively,
Zhou likened the coupling of carbon nanotube TFTS and IGZO TFTS to the Chinese philosophy of yin and yang."
With this development, Zhou and his team have circumvented the difficulty of creating n-type carbon nanotube TFTS
and p-type IGZO TFTS by creating a hybrid integration of p-type carbon nanotube TFTS and n-type IGZO TFTS and demonstrating a large-scale integration of circuits.
Up to this point, all carbon nanotube-based transistors had a maximum number of 200 transistors.""We believe this is a technological breakthrough,
"The next step for Zhou and his team will be to build more complicated circuits using a CNT
"Zhou and Chen believe that carbon nanotube technology, including this new CNT-IGZO hybrid, will be commercialized in the next 5-10 years."
"I believe that this is just the beginning of creating hybrid integrated solutions, "said Zhou.""We will see a lot of interesting work coming up. g
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