Nanodot: the original nanotechnology weblog

There is widespread agreement that the successful development and use of nanotechnology depends on showing that nanotech materials are safe—for human health and for the environment. A new study will trace the movement of nanoparticles through the environment and determine their impact on health and natural systems. A particular focus is to find out what alterations fullerenes might undergo as a consequence of interactions with microbes in the environment. From Rice University, via AAAS EurekAlert “NSF-funded Rice study will trace path of nanomaterials“:

Researchers want to know if particles can be transported through food chain

Working to ensure the safe use of nanomaterials is the basis of a new Rice study funded by the National Science Foundation.

Led by Pedro Alvarez, the George R. Brown Professor and chair of the Civil and Environmental Engineering Department, and Vicki Colvin, the Pitzer-Schlumberger Professor of Chemistry and director of the Center for Biological and Environmental Nanotechnology, the study will trace tagged nanoparticles to increase understanding of how they move through the environment and what impact they may have on the health and function of natural systems.

With industrial-scale production of materials that use nanoparticles on the near horizon, Alvarez said now is the time to address concerns over their safety. Read the rest of this entry »

Nanotech researchers continue to find novel nanostructures with promising applications. A web of single-crystalline titanium disilicide absorbs light efficiently and may be a useful catalyst to split water to furnish hydrogen for fuel. From Boston College, via AAAS EurekAlert “Scientists grow ‘nanonets’ able to snare added energy transfer“:

Using two abundant and relatively inexpensive elements, Boston College chemists have produced nanonets, a flexible webbing of nano-scale wires that multiplies surface area critical to improving the performance of the wires in electronics and energy applications.

Researchers grew wires from titanium and silicon into a two-dimensional network of branches that resemble flat, rectangular netting, Assistant Professor of Chemistry Professor Dunwei Wang and his team report in the international edition of the German Chemical Society journal Angewandte Chemie [citation].

By creating nanonets, the team conquered a longstanding engineering challenge in nanotechnology: creating a material that is extremely thin yet maintains its complexity, a structural design large or long enough to efficiently transfer an electrical charge.

“We wanted to create a nano structure unlike any other with a relatively large surface area,” said Wang. “The goal was to increase surface area and maintain the structural integrity of the material without sacrificing surface area and thereby improving performance.”

—Jim

In experiments in cell culture and in mice, adding the ability to target nanotech cancer therapy to the mitochondria within cancer cells renders the treatment more effective. One of the drugs made more effective may help to overcome the multiple drug resistance that develops in many tumors. From Nanowerk News “Targeting nanoparticles to specific locations inside cancer cells increases kills“:

The ability to target nanoparticles to specific types of cancer cells is one of the main reasons that nanoparticles have gained favor as a promising drug delivery vehicle. By increasing the amount of an anticancer agent that gets to tumor cells, as opposed to healthy cells, researchers hope to minimize the potential side effects of therapy while maximizing therapeutic response. Now, a team of investigators at Northeastern University has taken this approach one step farther by targeting the specific location inside a tumor cell, where the drug ceramide exerts its cell-killing activity.

Reporting its work in the journal Nano Letters (”Organelle-targeted nanocarriers: specific delivery of liposomal ceramide to mitochondria enhances its cytotoxicity in vitro and in vivo“), a team of investigators led by Volkmar Weissig, Ph.D., who has since moved to the Midwestern University College of Pharmacy in Glendale, AZ, developed a lipid-based nanoparticle and decorated its surface with a molecule known as triphenylphosphonium cation, which is known to be taken up specifically by mitochondria, the cell’s energy-producing organelles. Read the rest of this entry »

Characterization of graphene continues to reveal unusual properties that recommend it as a material for nanotech applications. Add to graphene’s record-breaking strength the discovery that graphene beams are unexpectedly stiff. From nanotechweb.org, written by Belle Dumé (requires free registration) “Graphene flakes stiffen up“:

Researchers have succeeded in making large sheets of graphene that measure up to 0.1 mm across and have found that the material is extraordinarily rigid, being able to support a thousand times its own weight. This means that the material could be incorporated into different technologies, such as micromechanical systems, and is ideal for use in electron microscopy.

Until recently, scientists thought that graphene — a one-atom thick material — was weak and flexible and would spontaneously roll or fold up into nanotube-like structures. Read the rest of this entry »

The newest addition to the toolkit for using DNA as a nanotech building block is the ability to program the circumference of nanotubes made from DNA. From nanotechweb.org, written by Belle Dumé (requires free registration) “DNA tubes control their size“:

Being able to synthesize nanostructures with controlled size is an important goal in nanotechnology. Now, researchers in the US have succeeded in exploiting modular single-stranded DNA building blocks to create molecular tubes with predefined circumferences. Such tubes could eventually be used as templates to make nanowires with controlled electronic properties for future nanoelectronic devices.

“We describe a simple modular approach to programming molecular-tube circumferences,” team member Peng Yin of Caltech told nanotechweb.org. “Single-step annealing results in the self-assembly of long tubes displaying monodisperse circumferences of 4, 5, 6, 7, 8, 10 or 20 DNA helices.” Read the rest of this entry »

KurzweilAI.net points us to this CNET News report that Ray Kurzweil’s concept of an impending “singularity,” in which machine intelligence surpasses human intelligence, has garnered support from Intel’s Chief Technology Officer Justin Rattner. From “Intel touts progress toward intelligent computers” by Stephen Shankland:

I hope Intel warned the Luddites and pessimists away at the door, because the chipmaker had a lot of bullish statements Thursday [August 21] about its belief that computers will become smarter than humans.

At the Intel Developer Forum here, Intel Chief Technology Officer Justin Rattner showed off a number of technologies in computing, robotics, and communication that he cited as evidence that Ray Kurzweil’s concept of “singularity,” when machine intelligence surpasses human intelligence, is impending. Demonstrations spotlighted the wireless transmission of electrical power, dextrous robots with new sensory abilities, a direct interface to the brain, programmable materials that can be used for shape-shifting devices such as resizable cell phones, and silicon photonics that enables chips to communicate with photons rather than electrons.

“We’re making steady progress toward Ray Kurzweil’s singularity,” Rattner said.

—Jim

Whether you are an American Express cardholder or not, you can vote for an innovative effort to inspire undergraduates to strive for fundamental advances in our ability to control the aging process. An Email this morning from David Gobel, Chief Executive Officer of the Methuselah Fund, said the project had 1200 nominations. I just checked and the number is now 1464. Keep the momentum building! From David Gobel:

Hi - We are at 1200 nominations to be in the running for the $1.5 million American Express Challenge Undergrads Fighting Age Related Disease researcher scholarships this morning

I believe we’ll need to have another 1,000 nominations over the next 4 days, and that this is absolutely doable. Now that we are solidly in the running, what can we do to dramatically improve our position? It’s totally important to note that of ALL the projects, ours is by far the most commented upon which counts heavily in the final selection.

From Aubrey de Grey

Calling All Who Support Extending Healthy Life….

Methuselah Foundation needs your help now - we are supporting a project named “Undergrads Fighting Age Related Disease” which has been submitted as part of the American Express Members Project initiative.

To advance this critical project please go to http://www.membersproject.com/project/view/BVVE2C

We need to get only 1,000 more votes in the next 4 days (by Sept 1, 2008) so please support your cause and vote now. Here are the instructions. Read the rest of this entry »

Government-sponsored discussions of the implications for society of advanced nanotechnology and other emerging technologies have taken place and are ongoing in both the US and Europe. A recent Nanowerk Spotlight written by Michael Berger gives an update of deliberations in Europe and compares and contrasts the US and European approaches. From “Europe and the U.S. take different approaches to Converging Technologies“:

The two differing approaches that the European Union and the U.S. take in tackling converging technologies is exemplary for the philosophical difference in how these two geographies approach the development of new technologies. Policies in the U.S., especially during the past eight years, have been, well, shaped is not the right word here, let’s say drifting, towards a purely market-driven approach to technology development: the government’s job was to provide sufficient basic R&D funding, keep a minimum of consumer safety levels, but otherwise not to get into the way of industrial activities. In addition, a major driver and funding agent for emerging technologies has been the military (for instance, over 30% of all federal investment dollars the U.S. spends on nanotechnology come from the U.S. Department of Defense — “Military nanotechnology - how worried should we be?”). Read the rest of this entry »

The protein engineering pathway to advanced nanotech (see “Protein Bioengineering Overview”, paper 10 of the Productive Nanosystems Roadmap Working Group Proceedings—a 14.6 MB PDF) might benefit if proteins could be arrayed on a surface so that they could be quickly and easily scanned for function or interactions with other molecules. Protein ‘chips’ developed by UK scientists for rapid disease detection and drug discovery might be just what is needed. From the University of Manchester, via AAAS EurekAlert “Chips are down as Manchester makes protein scanning breakthrough“:

Scientists at The University of Manchester have developed a new and fast method for making biological ‘chips’ — technology that could lead to quick testing for serious diseases, fast detection of MRSA infections and rapid discovery of new drugs.

Researchers working at the Manchester Interdisciplinary Biocentre (MIB) and The School of Chemistry have unveiled a new technique for producing functional ‘protein chips’ in a paper in the Journal of the American Chemical Society [abstract]…

Protein chips — or ‘protein arrays’ as they are more commonly known — are objects such as slides that have proteins attached to them and allow important scientific data about the behaviour of proteins to be gathered.

Functional protein arrays could give scientists the ability to run tests on tens of thousands of different proteins simultaneously, observing how they interact with cells, other proteins, DNA and drugs. Read the rest of this entry »

Two stories today in ScienceDaily point to different nanotech applications that could enable a solar solution to our energy problems—one including the use of self-repairing nanosystems. “Converting Sunlight To Cheaper Energy” describes the use of photoactive nanoscale systems to develop molecular electronics. Organic molecules and fullerenes will be used to make inexpensive photovoltaics and light emitting diodes:

Organic photovoltaics and organic LEDs are made up of thin films of semiconducting organic compounds that can absorb photons of solar energy. Typically an organic polymer, or a long, flexible chain of carbon-based material, is used as a substrate on which semiconducting materials are applied as a solution using a technique similar to inkjet printing.

…[South Dakota State University] scientists plan to use the variable band gap polymers to build multi-junction polymer solar cells or photovoltaics.

These devices use multiple layers of polymer/fullerene films that are tuned to absorb different spectral regions of solar energy.

Ideally, photons that are not absorbed by the first film layer pass through to be absorbed by the following layers.

The devices can harvest photons from ultraviolet to visible to infrared in order to efficiently convert the full spectrum of solar energy to electricity. Read the rest of this entry »

Advanced nanotech would benefit from the ability to engineer atomically precise structures on nanoparticles. In a step in that direction, UK scientists have developed a combined computational and experimental method to determine how specific peptides self-assemble on the surface of a gold nanoparticle—in particular how closely spaced on the surface of the nanoparticle the peptides have to be to form chemical bonds. Via ScienceDaily, a news release from UK Biotechnology and Biological Sciences Research Council (includes images and molecular dynamics animations) “Scientists overcome nanotech hurdle“:

When you make a new material on a nanoscale how can you see what you have made? A team lead by a Biotechnology and Biological Sciences research Council (BBSRC) fellow has made a significant step toward overcoming this major challenge faced by nanotechnology scientists. With new research published today (13 August) in ChemBioChem [abstract], the team from the University of Liverpool, The School of Pharmacy (University of London) and the University of Leeds, show that they have developed a technique to examine tiny protein molecules called peptides on the surface of a gold nanoparticle. This is the first time scientists have been able to build a detailed picture of self-assembled peptides on a nanoparticle and it offers the promise of new ways to design and manufacture novel materials on the tiniest scale — one of the key aims of nanoscience. Read the rest of this entry »

In a study with breast cancer in mice, a nanotech cancer therapy suppresses tumor growth with minimal side effects. Taking advantage of the fact that the blood vessels in tumor tissue are leakier than in normal tissue, carbon nanotubes of the right size and with the proper chemical coating deliver more tumor-killing drug to tumors, while sparing normal tissue. In future experiments, the researchers may add molecules that specifically target tumor cells to achieve even greater specificity. ScienceDaily features a story from Stanford University News, written by Louis Bergeron “Nanotubes deliver high-potency punch to cancer tumors in mice“:

The problem with using a shotgun to kill a housefly is that even if you get the pest, you’ll likely do a lot of damage to your home in the process. Hence the value of the more surgical flyswatter.

Cancer researchers have long faced a similar situation in chemotherapy: how to get the most medication into the cells of a tumor without “spillover” of the medication adversely affecting the healthy cells in a patient’s body.

Now researchers at Stanford University have addressed that problem using single-walled carbon nanotubes as delivery vehicles. The new method has enabled the researchers to get a higher proportion of a given dose of medication into the tumor cells than is possible with the “free” drug—that is, the one not bound to nanotubes—thus reducing the amount of medication that they need to inject into a subject to achieve the desired therapeutic effect. Read the rest of this entry »

The production of syngas, a mixture of carbon monoxide, carbon dioxide, and hydrogen, from coal or other carbon source is an established industrial technology. A new nanotech catalyst now enables the efficient conversion of syngas to ethanol. From an Ames Laboratory news release (via ScienceDaily) “Turning Waste Material into Ethanol“

Say the word “biofuels” and most people think of grain ethanol and biodiesel. But there’s another, older technology called gasification that’s getting a new look from researchers at the U.S. Department of Energy’s Ames Laboratory and Iowa State University. By combining gasification with high-tech nanoscale porous catalysts, they hope to create ethanol from a wide range of biomass, including distiller’s grain left over from ethanol production, corn stover from the field, grass, wood pulp, animal waste, and garbage. Read the rest of this entry »

Silver nanoparticles continue to show promise for killing bacteria, especially in a hospital environment. Now a Swiss team has shown that a combination of silver and calcium phosphate nanoparticles provides an even more effective nanotech antiseptic. From Nanowerk News “New nanoparticle film up to 1000 times more effective at killing E. coli bacteria“:

Chemical Engineers in Switzerland have created a plastic film that’s up to 1000 times more effective at killing E. coli bacteria cells than conventional methods.

The team from the Swiss Federal Institute of Technology, Zurich have discovered that coating the film with a mix of silver and calcium phosphate nano-particles proves deadly to bacteria.

Wendelin Stark, a chemical engineer and leader of the project explained that it had been previously impossible to apply silver in a targeted and measured way. However, by using a film and applying the silver to the calcium phosphate, he believes the problem has been overcome: “Within 24 hours of the plastic film being applied to a surface, less than 1 bacterium out of 1 million bacteria will survive.”

Because bacteria rely on calcium for their metabolism, the 20-50 nanometer calcium phosphate particles are used by the micro-organisms as nutrition. When the bacteria consume the calcium phosphate, this releases thousands of small silver 1-2 nanometer particles. It’s these tiny silver particles that kill the bacteria and prevent germs from growing and spreading.

The polymer film only emits silver if bacteria are growing in the vicinity.

The research was published in Small (abstract).
—Jim

The Center for Nanotechnology in Society at Arizona State University is one of two centers funded by the National Science Foundation to study nanotechnology in society. One of their tools for studying the impact of nanotech upon society is the National Citizens’ Technology Forum (NCTF). They have recently published the results of their National Citizens’ Technology Forum: Public Deliberation about Nanotechnology for Human Enhancement. From their downloadable brochure:

In March 2008, eighty-six people across six nationwide panels participated in the National Citizens’ Technology Forum on “Human Enhancement Through Nanotechnology.” These citizens ranged from teens to seniors and had no previous expertise or experience in nanotechnology. They studied background material, met face-to-face, and participated in nine, two-hour Internet discussion forums with scientist experts. During their final meeting, each panel wrote a Citizen’s Report that outlines their optimism, concerns and recommendations regarding human enhancement technologies.

The reports address socio-economic, safety, environmental, health and governance issues, as well as regulatory challenges and human identity concerns. This project gives average citizens a voice in the early stages of nano-scale science and engineering research and development. It is noteworthy that every report implores policymakers, research scientists, and the private sector to recognize that real-time citizen input is essential to fully understanding the societal implications of emerging technologies.

The final reports from the six sites are available in their entirety here.
—Jim

To form practical nanotech circuits from arrays of nanowires, it is necessary to integrate different types of nanowires into multifunctional circuits. Two different types of nanowires (cadmium selenide for light sensors and germanium core/silicon shell for field-effect transistors) have been integrated on a chip to detect and amplify optical signals. From Lawrence Berkeley National Laboratory (credit PhysOrg.com) “A First in Integrated Nanowire Sensor Circuitry“:

Scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California at Berkeley have created the world’s first all-integrated sensor circuit based on nanowire arrays, combining light sensors and electronics made of different crystalline materials. Their method can be used to reproduce numerous such devices with high uniformity.

Nanostructures made with specific chemical, electronic, and other properties have a number of advantages over the same materials in bulk. For example, a nanowire is an ideal shape for a light detector; being virtually one-dimensional, practically “all surface,” a nanowire is not only highly sensitive to light energy, but its electronic response is greatly enhanced as well.

To be practical, however, the photosensors must be integrated with electronics on the same chip. And the materials that make an ideal photosensor are necessarily different from those that make a good transistor. Read the rest of this entry »

Nanotech methods offer a variety of ways to alter the properties of nanostructures to optimize drug delivery. A process that allows the fabrication of different shapes of particles varying in size from about 100 nm to several micrometers demonstrates that long particles are internalized by cancer cells more efficiently than are round particles. From the University of North Carolina at Chapel Hill (credit PhysOrg.com) “UNC study: shape, not just size, impacts effectiveness of emerging nano-medicine therapies“:

In the budding field of nanotechnology, scientists already know that size does matter.

But now, researchers at the University of North Carolina at Chapel Hill have shown that shape matters even more — a finding that could lead to new and more effective methods for treating cancer and other diseases, from diabetes and multiple sclerosis to arthritis and obesity.

A team of researchers led by Joseph DeSimone, Ph.D., Chancellor’s Eminent Professor of Chemistry in UNC’s College of Arts and Sciences and William R. Kenan, Jr. Distinguished Professor of Chemical Engineering at North Carolina State University, and Stephanie Gratton, a graduate student in DeSimone’s lab, have demonstrated that nanoparticles designed with a specific shape, size and surface chemistry are taken up into cells and behave differently within cells depending on these attributes. Read the rest of this entry »

Nanotech has fashioned from graphene a one atom-thick membrane impermeable even to helium gas. From “World’s Thinnest Balloon Developed: Just One Atom Thick“:

Researchers in New York are reporting development of the world’s thinnest balloon, made of a single layer of graphite just one atom thick. This so-called graphene sealed microchamber is impermeable to even the tiniest airborne molecules, including helium.

It has a range of applications in sensors, filters, and imaging of materials at the atomic level.

Paul L. McEuen and colleagues note that membranes are fundamental components of a wide variety of physical, chemical and biological systems, found in everything from cellular compartments to mechanical pressure sensing. Graphene, a single layer of graphite, is the upper limit: A chemically stable and electrically conducting membrane just one atom thick. The researchers wanted to answer whether such an atomic membrane would be impermeable to gas molecules and easily incorporated into other devices.

Their data showed that graphene membranes were impermeable to even the smallest gas molecules. These results show that single atomic sheets can be integrated with microfabricated structures to create a new class of atomic scale membrane-based devices.

The research was published in Nano Letters (abstract)
—Jim

Nanotech has taken a major step along the road to molecular electronics with the demonstration that one molecule of benzene can form a highly conductive junction between two platinum electrodes. From an article on nanotechweb.org, written by Belle Dumé (requires free registration) “Ballistic breakthrough could lead to molecular logic gates“:

The first highly-conductive connection between a single organic molecule and a metal electrode has been made by an international team of physicists. This achievement could lead to the development of ‘molecular electronics’ devices with the potential to be smaller and faster than conventional transistors and logic gates.

The majority of electronic devices are made from just a handful of semiconductor materials — the most common being silicon. However, some organic molecules such as DNA appear to have electronic properties similar to traditional semiconductors and some researchers believe that some types of molecules could be used to make electronic devices.

A potential benefit of such devices is that molecules are extremely small compared to semiconductor structures, which could help manufacturers pack more and more circuits onto a chip.

However, it has proven very difficult to connect single molecules to a metal electrode such that electrons are conducted easily between the two. These junctions are essential for making real-world devices like transistors and logic gates. Read the rest of this entry »

The SmallTimes web site reports the introduction of H.R. 6661, which establishes a prize competition for five key areas of nanotech. From “Nanotechnology prize competition bill to drive U.S. innovation“:

Congressman Dan Lipinski (D-IL) , Vice Chairman of the House Science and Technology Committee, and Congressman (R-MO) Todd Akin, have introduced H.R. 6661, the Nanotechnology Innovation and Prize Competition Act, which establishes an X-Prize competition for nanotechnology.

H.R. 6661 would stimulate public-private partnership and focus investment towards key goals. The bill identifies five key categories — green nanotechnology, alternative energy, human health, nanoelectronics, and commercialization of consumer products — and establishes a board comprised of government and private sector experts to select criteria for prize competitions.

…The bill also authorizes the government to contract with an outside organization, such as the X-PRIZE Foundation, to administer the competition. This organization, and the board, also will recruit private contributions to fund the prize awards. In this way, H.R. 6661 enables the government to leverage a relatively small amount of resources to stimulate a much greater level of investment in nanotech research.

—Jim