David Kirkpatrick

May 27, 2010

Killing tumors with gold nanoparticles

Via KurzweilAI.net — The latest in fighting cancer with nanotechnology.

Self-Assembling Gold Nanoparticles Use Light to Kill Tumor Cells
PhysOrg.com, May 26, 2010

Researchers at the University of California, Los Angeles, have developed a method for creating supramolecular assemblies of gold nanoparticles that function as highly efficient photothermal agents for delivery to tumors, using a laser beam to heat the nanoparticles above 374 degreesC, the temperature at which explosive microbubbles form.
Read Original Article>>

February 12, 2010

Nanoparticles, optics and electricity

(Number one of two posts on nanotechnology and electricity. Hit this link for part two)

This sounds like a tech with a range of applications.

The release:

Penn material scientists turn light into electrical current using a golden nanoscale system

IMAGE: Material scientists at the Nano/Bio Interface Center of the University of Pennsylvania have demonstrated the transduction of optical radiation to electrical current in a molecular circuit.

Click here for more information.

PHILADELPHIA –- Material scientists at the Nano/Bio Interface Center of the University of Pennsylvania have demonstrated the transduction of optical radiation to electrical current in a molecular circuit. The system, an array of nano-sized molecules of gold, respond to electromagnetic waves by creating surface plasmons that induce and project electrical current across molecules, similar to that of photovoltaic solar cells.

The results may provide a technological approach for higher efficiency energy harvesting with a nano-sized circuit that can power itself, potentially through sunlight. Recently, surface plasmons have been engineered into a variety of light-activated devices such as biosensors.

It is also possible that the system could be used for computer data storage. While the traditional computer processor represents data in binary form, either on or off, a computer that used such photovoltaic circuits could store data corresponding to wavelengths of light.

Because molecular compounds exhibit a wide range of optical and electrical properties, the strategies for fabrication, testing and analysis elucidated in this study can form the basis of a new set of devices in which plasmon-controlled electrical properties of single molecules could be designed with wide implications to plasmonic circuits and optoelectronic and energy-harvesting devices.

Dawn Bonnell, a professor of materials science and the director of the Nano/Bio Interface Center at Penn, and colleagues fabricated an array of light sensitive, gold nanoparticles, linking them on a glass substrate. Minimizing the space between the nanoparticles to an optimal distance, researchers used optical radiation to excite conductive electrons, called plasmons, to ride the surface of the gold nanoparticles and focus light to the junction where the molecules are connected. The plasmon effect increases the efficiency of current production in the molecule by a factor of 400 to 2000 percent, which can then be transported through the network to the outside world.

In the case where the optical radiation excites a surface plasmon and the nanoparticles are optimally coupled, a large electromagnetic field is established between the particles and captured by gold nanoparticles. The particles then couple to one another, forming a percolative path across opposing electrodes. The size, shape and separation can be tailored to engineer the region of focused light. When the size, shape and separation of the particles are optimized to produce a “resonant” optical antennae, enhancement factors of thousands might result.

Furthermore, the team demonstrated that the magnitude of the photoconductivity of the plasmon-coupled nanoparticles can be tuned independently of the optical characteristics of the molecule, a result that has significant implications for future nanoscale optoelectronic devices.

“If the efficiency of the system could be scaled up without any additional, unforeseen limitations, we could conceivably manufacture a one-amp, one-volt sample the diameter of a human hair and an inch long,” Bonnell said.

###

The study, published in the current issue of the journal ACS Nano, was conducted by Bonnell, David Conklin and Sanjini Nanayakkara of the Department of Materials Science and Engineering in the School of Engineering and Applied Science at Penn; Tae-Hong Park of the Department of Chemistry in the School of Arts and Sceicnes at Penn; Parag Banerjee of the Department of Materials Science and Engineering at the University of Maryland; and Michael J. Therien of the Department of Chemistry at Duke University.

This work was supported by the Nano/Bio Interface Center, National Science Foundation, the John and Maureen Hendricks Energy Fellowship and the U.S. Department of Energy.

February 11, 2010

Gold and nanotechnology

Filed under: Business, Science, Technology — Tags: , , , , — David Kirkpatrick @ 4:02 am

A release from the World Gold Council and Cientifica Ltd., smoking hot from the inbox this morning (the crazy formatting is from the original and I didn’t feel like fixing it, so apologies for reading difficulties):

Gold at Forefront of ‘Nanotechnology Revolution’

LONDON, February 11/PRNewswire/ —

– World Gold Council Research Paper Demonstrates Important Applications
in Development Using Gold Nanoparticles

World Gold Council (WGC) has today published ‘Gold for Good: Gold and
nanotechnology in the age of innovation’, a research paper detailing new
scientific and technological innovations using gold. The report, which was
produced in conjunction with Cientifica Ltd, the world’s leading source of
global business and investor intelligence about nanotechnologies,
demonstrates how gold nanoparticles offer the potential to overcome many of
the serious issues facing mankind over the coming decades.

Gold nanoparticles exhibit a variety of unique properties which, when
harnessed and manipulated effectively, lead to materials whose uses are both
far-ranging in their potential and cost effective. This report explores the
many different applications that are being developed across the fields of
health, environment and technology.

Trevor Keel, Nanotechnology Project Manager at World Gold Council said:

“The opportunities and possibilities identified in this report are just a
subset of the amazing scope to use gold in the era of nanotechnology. As a
readily available and well understood material, gold nanoparticles are ideal
for use in a vast array of applications that improve our lives. WGC is
looking to promote and invest in the development of gold-based innovations
through Innovations Partnerships, so that the full benefits of gold
nanotechnology can be realized.”

Tim Harper, founder of Cientifica Ltd, said:

“Over the last decade, almost $50 billion of government funding has been
invested into nanotechnologies, and this investment is now starting to bear
fruit with a steady stream of commercially viable nanotechnologies which are
positively impacting human health, the environment and technology. This paper
demonstrates the many varied applications in which gold nanotechnology can
improve society’s standard of living.”

Health: Gold has a long history in the biomedical field stretching back
almost five thousand years. However the dawn of the ‘nano-age’ has really
broadened the potential of gold in biomedical applications and today, gold
nanoparticles are being employed in entirely novel ways to achieve
therapeutic effects.

Tumor targeting technologies which exploit gold’s inherent
bio-compatibility are being developed to deliver drugs directly into
cancerous tumours. Additionally, simple, cost effective and sensitive
diagnostic tests are being developed for the early detection of prostate and
other cancers.

Environment: Environmental concerns have never been more prominent –
energy and clean water scarcity, global warming and pollution are all major
issues that need to be addressed. Gold nano-particle based technologies are
showing great promise in providing solutions to a number of environmentally
important issues from greener production methods of the chemical feedstocks,
to pollution control and water purification.

Gold-based catalysts are being developed that can effectively prevent the
release of highly toxic forms of mercury into the atmosphere, the reduction
of chemicals from green feedstock, and also for water purification and
contaminant detection. In addition, gold is being used in meeting the
challenge of constructing cost effective and efficient fuel cells, a key
‘clean-energy’ technology of the future.

Advanced technology: Gold is already a well established
material in the electronics industry and the use of gold can only increase as
the worlds of electronics and nanotechnology interact further in the future.
Gold is being developed for conductive nanoparticle inks for plastic
electronics because of its material compatibility, inherent durability and
proven track record of reliability. Gold nanotechnologies have also been
shown to offer functional benefits for visual display technologies like touch
sensitive screens and potentially for use in advanced data storage
technologies including advanced flash memory devices.

The full paper can be downloaded from:

http://www.gold.org/assets/file/rs_archive/gold_and_nanotechnology_in_the
_age_of_innovation.pdf

(Due to the length of this URL, it may be necessary to copy and paste
this hyperlink into your Internet browser’s URL address field. Remove the
space if one exists.)

OR

http://cientifica.eu/blog/white-papers/gold/

Innovation Partnerships

World Gold Council works directly with partner companies via Innovation
Partnerships. These support research and development of new practical
applications for the metal, drawing on a genuine commercial market
requirement for innovation. Partner organisations include (but are not
limited to) precious metal, chemical, electronics, materials and biomedical
companies, ranging from small enterprises through to established
international businesses. Interested companies are invited to contact World
Gold Council for further details.

During 2009-2010 World Gold Council is particularly interested in
receiving proposals relating to the following areas:

Industrial catalysts (including catalysts for pollution control and
chemical processing)

Biomedical applications (including medical diagnostics, therapeutics and
materials)

Advanced electronics (including any technology or component likely to be
used in next-generation devices)

Fuel cell systems (including applications both within the fuel cell
structure and hydrogen processing infrastructure)

Optical materials (including nanotechnology, chemicals and coatings)

Companies interested in collaborating with World Gold Council
are invited to make contact.

Notes to Editors:

World Gold Council

World Gold Council’s mission is to stimulate and sustain the demand for
gold and to create enduring value for its stakeholders. It is funded by the
world’s leading gold mining companies. For further information please visit
http://www.gold.org.

Cientifica

Cientifica Ltd, based in London, is one of the world’s best-respected
consultancy companies in the field of emerging technologies and technology
commercialization. It provides global business intelligence and strategic
consulting services to industry, governments and investors worldwide.

http://www.cientifica.eu

June 17, 2009

Nonstick nanogold

Cool and useful — “teflon” gold.

The release:

Nonstick and laser-safe gold aids laser trapping of biomolecules

IMAGE: The gold posts in this colorized micrograph, averaging 450 nanometers in diameter, are used to anchor individual biomolecules such as DNA for studies of their mechanical properties. The background surface…

Click here for more information. 

Biophysicists long for an ideal material—something more structured and less sticky than a standard glass surface—to anchor and position individual biomolecules. Gold is an alluring possibility, with its simple chemistry and the ease with which it can be patterned. Unfortunately, gold also tends to be sticky and can be melted by lasers. Now, biophysicists at JILA have made gold more precious than ever—at least as a research tool—by creating nonstick gold surfaces and laser-safe gold nanoposts, a potential boon to laser trapping of biomolecules.

JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.

JILA’s successful use of gold in optical-trapping experiments, reported in Nano Letters,* could lead to a 10-fold increase in numbers of single molecules studied in certain assays, from roughly five to 50 per day, according to group leader Tom Perkins of NIST. The ability to carry out more experiments with greater precision will lead to new insights, such as uncovering diversity in seemingly identical molecules, and enhance NIST’s ability to carry out mission work, such as reproducing and verifying piconewton-scale force measurements using DNA, Perkins says. (A one-kilogram mass on the Earth’s surface exerts a force of roughly 10 newtons. A piconewton is 0.000 000 000 001 newtons. See “JILA Finds Flaw in Model Describing DNA Elasticity” NIST Tech Beat, Sept. 13, 2007.)

Perkins and other biophysicists use laser beams to precisely manipulate, track and measure molecules like DNA, which typically have one end bonded to a surface and the other end attached to a micron-sized bead that acts as a “handle” for the laser. Until now, creating the platform for such experiments has generally involved nonspecifically absorbing fragile molecules onto a sticky glass surface, producing random spacing and sometimes destroying biological activity. “It’s like dropping a car onto a road from 100 feet up and hoping it will land tires down. If the molecule lands in the wrong orientation, it won’t be active or, worse, it will only partially work,” Perkins says.

Ideally, scientists want to attach biomolecules in an optimal pattern on an otherwise nonstick surface. Gold posts are easy to lay down in desired patterns at the nanometer scale. Perkins’ group attached the DNA to the gold with sulfur-based chemical units called thiols (widely used in nanotechnology), an approach that is mechanically stronger than the protein-based bonding techniques typically used in biology. The JILA scientists used six thiol bonds instead of just one between the DNA and the gold posts. These bonds were mechanically strong enough to withstand high-force laser trapping and chemically robust enough to allow the JILA team to coat the unreacted gold on each nanopost with a polymer cushion, which eliminated undesired sticking. “Now you can anchor DNA to gold and keep the rest of the gold very nonstick,” Perkins says.

Moreover, the gold nanoposts were small enough—with diameters of 100 to 500 nanometers and a height of 20 nanometers—that the scientists could avoid hitting the posts directly with lasers. “Like oil and water, traditionally laser tweezers and gold don’t mix. By making very small islands of gold, we positioned individual molecules where we wanted them, and with a mechanical strength that enables more precise and additional types of studies,” Perkins says.

 ###

 The research was supported by a W.M. Keck Grant in the RNA Sciences, the National Science Foundation, and NIST.

* D.H. Paik, Y. Seol, W. Halsey and T.T. Perkins. Integrating a high-force optical trap with gold nanoposts and a robust gold-DNA bond. Nano Letters. Articles ASAP (As Soon As Publishable) Publication Date (Web): June 3, 2009 DOI: 10.1021/nl901404s.

March 4, 2009

Light bending nanoparticles

Filed under: Science, Technology — Tags: , , , — David Kirkpatrick @ 3:58 pm

From KurzweilAI.net — Nanotechnology news from Rice University on light-bending nanoparticles.

Scientists Create Light-Bending Nanoparticles
PhysOrg.com, Mar. 3, 2009

Rice University researchers discovered that Cup-shaped gold nanostructures can bend light in a controllable way, acting like three-dimensional nano-antennas, Rice University researchers have discovered.

This property should prove useful in developing new optical materials and devices, such as solar cells, light attenuators, and chip-to-chip optical interconnects.

 
Read Original Article>>

January 4, 2009

3D DNA nantubes

Pretty cool research here.

The release:

The gold standard: Biodesign Institute researchers use nanoparticles to make 3-D DNA nanotubes

DNA nanotubes may soon find their way into a new generation of ultra-tiny electronic and biomedical innovations

VIDEO: 5-nm size gold nanoparticles wrap around the perimeter of a DNA nanotube in a spiral pattern. The 3-D structures have been recreated from cryoelectron tomographic imaging.

Click here for more information. 

Arizona State University researchers Hao Yan and Yan Liu imagine and assemble intricate structures on a scale almost unfathomably small. Their medium is the double-helical DNA molecule, a versatile building material offering near limitless construction potential.

In the January 2, 2009 issue of Science, Yan and Liu, researchers at ASU’s Biodesign Institute and faculty in the Department of Chemistry and Biochemistry, reveal for the first time the three-dimensional character of DNA nanotubules, rings and spirals, each a few hundred thousandths the diameter of a human hair. These DNA nanotubes and other synthetic nanostructures may soon find their way into a new generation of ultra-tiny electronic and biomedical innovations.

Yan and Liu are working in the rapidly proliferating field of structural DNA nanotechnology. By copying a page from nature’s guidebook, they capitalize on the DNA molecule’s remarkable properties of self-assembly. When ribbonlike strands of the molecule are brought together, they fasten to each other like strips of Velcro, according to simple rules governing the pairing of their four chemical bases, (labeled A, C, T and G). From this meager alphabet, nature has wrung a mind-bending multiplicity of forms. DNA accomplishes this through the cellular synthesis of structural proteins, coded for by specific sequences of the bases. Such proteins are fundamental constituents of living matter, forming cell walls, vessels, tissues and organs. But DNA itself can also form stable architectural structures, and may be artificially cajoled into doing so.

VIDEO: In this DNA nanotube configuration, again using 5-nm size gold nanoparticles, the nanoparticles form stacked rings around the DNA.

Click here for more information. 

In his research, Yan has been much inspired by nanoscale ingenuity in the natural world: “Unicellular creatures like oceanic diatoms,” he points out, “contain self-assembled protein architectures.” These diverse forms of enormous delicacy and organismic practicality are frequently the result of the orchestrated self-assembly of both organic and inorganic material.

Scientists in the field of structural DNA nanotechnology, including Dr. Yan’s team, have previously demonstrated that pre-fab DNA elements could be induced to self-assemble, forming useful nanostructural platforms or “tiles.” Such tiles are able to snap together—with jigsaw puzzle-piece specificity—through base pairing, forming larger arrays.

Yan and Liu’s work in Science responds to one of the fundamental challenges in nanotechnology and materials science, the construction of molecular-level forms in three dimensions. To do so, the team uses gold nanoparticles, which can be placed on single-stranded DNA, compelling these flexible molecular tile arrays to bend away from the nanoparticles, curling into closed loops or forming spring-like spirals or nested rings, roughly 30 to 180 nanometers in diameter.

The gold nanoparticles, which coerce DNA strands to arc back on themselves, produce a force known as “steric hindrance,” whose magnitude depends on the size of particle used. Using this steric hindrance, Yan and Liu have shown for the first time that DNA nanotubules can be specifically directed to curl into closed rings with high yield.

When 5 nanometer gold particles were used, a milder steric hindrance directed the DNA tiles to curl up and join complementary neighboring segments, often forming spirals of varying diameter in addition to closed rings. A 10 nanometer gold particle however, exerted greater steric hindrance, directing a more tightly constrained curling which, produced mostly closed tubules. Yan stresses that the particle not only participates in the self-assembly process as the directed material, but also as an active agent, inducing and guiding formation of the nanotube.

VIDEO: Using 10-nm-size gold nanoparticles, the DNA nanotubes form a split branch structure, with both the spiral tube splitting into two smaller stacked rings.

Click here for more information. 

With the assistance of Anchi Cheng and Jonanthan Brownell at the Scripps Research Institute, they have used an imaging technique known as electron cryotomography to provide the first glimpses of the elusive 3-D architecture of DNA nanotubules. “You quickly freeze the sample in vitreous ice,” he explains, describing the process. “This will preserve the native conformation of the structure.” Subsequent imaging at various tilted angles allows the reconstruction of the three-dimensional nanostructure, with the gold particles providing enough electron density for crisp visualization. (see movies)

DNA nanotubules will soon be ready to join their carbon nanotube cousins, providing flexible, resilient and manipulatable structures at the molecular level. Extending control over 3-D architectures will lay the foundation for future applications in photometry, photovoltaics, touch screen and flexible displays, as well as for far-reaching biomedical advancements.

“The ability to build three-dimensional structures through self-assembly is really exciting, ” Yan says. “It’s massively parallel. You can simultaneously produce millions or trillions of copies.”

Yan and Liu believe that controlled tubular nanostructures bearing nanoparticles may be applied to the design of electrical channels for cell-cell communication or used in the construction of various nanoelectrical devices.

 

###

 

About the Biodesign Institute at ASU

The Biodesign Institute at Arizona State University pursues research to create personalized medical diagnostics and treatments, outpace infectious disease, clean the environment, develop alternative energy sources, and secure a safer world. Using a team approach that fuses the biosciences with nanoscale engineering and advanced computing, the Biodesign Institute collaborates with academic, industrial and governmental organizations globally to accelerate these discoveries to market. For more information, go to: www.biodesign.asu.edu

September 28, 2008

Green gold nanotech

The release from Friday:

MU scientists go green with gold, distribute environmentally friendly nanoparticles

Mizzou scientist named as one of the 25 most influential people in radiology

COLUMBIA, Mo. — Gold nanoparticles are everywhere. They are used in cancer treatments, automobile sensors, cell phones, blood sugar monitors and hydrogen gas production. However, until recently, scientists couldn’t create the nanoparticles without producing synthetic chemicals that had negative impacts on the environment. A new method, created by a University of Missouri research team, not only eliminates any negative environmental impact, but also has resulted in national and international recognition for the lead scientist. The research was published recently in the journal Small.

“I have always believed that nature is smarter and stronger than humankind,” said Kattesh Katti, professor of radiology and physics in MU’s School of Medicine and College of Arts and Science, senior research scientist at the MU Research Reactor, and director of the MU Cancer Nanotechnology Platform. “This new procedure to create nanoparticles is wonderfully simple, yet it will help create very complex components. There is so much to learn from energy generation, chemical and photochemical reactions of plants.”

Katti, who was recently recognized by rt Image magazine as one of the 25 most influential people in radiology, and his research team have formed Greennano Company, a company that is in the beginning stages of producing environmentally friendly gold nanoparticles. The company will focus on the development, commercialization and worldwide supply of gold nanoparticles for medical and technological applications. Katti believes that because of this new process to produce the nanoparticles, researchers are developing other ways to use them.

The MU research team, which was led by Katti, Raghuraman Kannan and Kavita Katti, found that by submersing gold salts in water and then adding soybeans, gold nanoparticles were generated. The water pulls a phytochemical out of the soybean that is effective in reducing the gold to nanoparticles. A second phytochemical from the soybean, also pulled out by the water, interacts with the nanoparticles to stabilize them and keep them from fusing with the particles nearby. This process creates nanoparticles that are uniform in size in a 100-percent green process. No toxic waste is generated.

“I’m very proud to be one among the list of ’25 Most Influential Scientists’ in the world, especially in the company of all time greats and former awardees including: Elias Zerhouni, director of National Institutes of Health (2003); Henry N. Wagner Jr., recognized as the Father of Nuclear Medicine (2004); Henry D. Royal, Peter S. Conti, past presidents of the Society of Nuclear Medicine; and Barry B. Goldberg, pioneer of ultrasound (2007),” Katti said. “This recognition is a tremendous honor and brings a large amount of prestige to our research group, the Departments of Radiology and Physics, the MU Research Reactor Center and the overall research and education enterprise of our University.”

“They all had one thing in common; they possessed the integrity, drive and passion deserving of the title ‘Most Influential,'” said Heather B. Koitzsch, publisher of rt Image. “In this year’s list, you’ll read about people who are changing the face of medicine, associations that are advocating for better patient care, and researchers whose efforts are uncovering new diagnostic techniques. Whether through speaking, campaigning, researching, creating or leading, someone who is “Most Influential” is committed to making things happen in radiology.”

 

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Katti’s research has been funded by the National Cancer Institute in the National Institutes of Health.

May 30, 2008

Gold nanoparticles safely penetrate cells

Filed under: Science, Technology — Tags: , , , , — David Kirkpatrick @ 5:19 pm

From KurzweilAI.net:

Nanoparticles of a Different Stripe
Technology Review, May 30, 2008

Gold nanoparticles coated with alternating stripes of hydrophobic and hydrophilic molecules can penetrate cells without killing them, MIT researchers have found.

Such materials could offer a more effective way to deliver drugs or imaging agents to the interior of a cell.

 
Read Original Article>>