Harvard & MIT Produce First Nano Foundry...From DNA!

Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University have unveiled a new method to form tiny 3D metal nanoparticles in prescribed shapes and dimensions using DNA, Nature's building block, as a construction mold.

The ability to mold inorganic nanoparticles out of materials such as gold and silver in precisely designed 3D shapes is a significant breakthrough that has the potential to advance laser technology, microscopy, solar cells, electronics, environmental testing, disease detection and more.

"We built tiny foundries made of stiff DNA to fabricate metal nanoparticles in exact three-dimensional shapes that we digitally planned and designed," said Peng Yin, senior author of the paper, Wyss core faculty member and Assistant Professor of Systems Biology at Harvard Medical School.

The Wyss team's findings, described in a paper titled "Casting Inorganic Structures with DNA Molds," were published today in Science. The work was done in collaboration with MIT's Laboratory for Computational Biology and Biophysics, led by Mark Bathe, senior co-author of the paper.

"The paper's findings describe a significant advance in DNA nanotechnology as well as in inorganic nanoparticle synthesis," Yin said. For the very first time, a general strategy to manufacture inorganic nanoparticles with user-specified 3D shapes has been achieved to produce particles as small as 25 nanometers or less, with remarkable precision (less than 5 nanometers). A sheet of paper is approximately 100,000 nanometers thick.

The 3D inorganic nanoparticles are first conceived and meticulously planned using computer design software. Using the software, the researchers design three-dimensional "frameworks" of the desired size and shape built from linear DNA sequences, which attract and bind to one another in a predictable manner.

"Over the years, scientists have been very successful at making complex 3D shapes from DNA using diverse strategies," said Wei Sun, a postdoctoral scholar in the Wyss' Molecular Systems Lab and the lead author of the paper. For example, in 2012, the Wyss team revealed how computer-aided design could be used to construct hundreds of different self-assembling one-, two-, and three-dimensional DNA nanoshapes with perfect accuracy. It is this ability to design arbitrary nanostructures using DNA manipulation that inspired the Wyss team to envision using these DNA structures as practical foundries, or "molds", for inorganic substances.

"The challenge was to translate this kind of 3D geometrical control into the ability to cast structures in other diverse and functionally-relevant materials, such as gold and silver," Sun said.

Just as any expanding material can be shaped inside a mold to take on a defined 3D form, the Wyss team set out to grow inorganic particles within the confined hollow spaces of stiff DNA nanostructures

The concept can be likened to the Japanese method of growing watermelons in glass cubes. By nurturing watermelon seeds to maturity inside cube-shaped glass boxes, Japanese farmers create cube-shaped mature melons that allow for densely-packed shipping and storage of the fruit.

The Wyss researchers similarly planted a miniscule gold "seed" inside the hollow cavity of their carefully designed cube-shaped DNA mold and then stimulated it to grow. Using an activating chemical solution, the gold seed grew and expanded to fill all existing space within the DNA framework, resulting in a cuboid nanoparticle with the same dimensions as its mold., with the length, width and height of the particle able to be controlled independently.

Next, researchers fabricated varied 3D polygonal shapes, spheres, and more ambitious structures, such as a 3D Y-shaped nanoparticle and another structure comprising a cuboid shape sandwiched between two spheres, proving that structurally-diverse nanoparticles could be shaped using complex DNA mold designs.

Given their unthinkably small size, it may come as a surprise that stiff DNA molds are proportionally quite robust and strong, able to withstand the pressures of expanding inorganic materials. Although the team selected gold seedlings to cast their nanoparticles, there is a wide range of inorganic nanoparticles that can be forcibly shaped through this process of DNA nanocasting.

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The Nanites are Coming! The Nanites are Coming!

For the first time, scientists have placed tiny motors inside living human cells and steered them magnetically.

The advance represents another step towards molecular machines that can be used, for example, to release drugs into specific locations within the body.

There is interest in the approach because it could enhance the benefits of drugs while minimising side effects.

The rocket-shaped metal particles were propelled using ultrasound pulses.

Materials scientist Prof Tom Mallouk, from Penn State University, and colleagues have published their research in the journal Angewandte Chemie International Edition.

"As these nanomotors move around and bump into structures inside the cells, the live cells show internal mechanical responses that no one has seen before," said Prof Mallouk.

"This research is a vivid demonstration that it may be possible to use synthetic nanomotors to study cell biology in new ways."

link.

huh

The Singularity is the new Grey Goo.

interesting thought, that.

Chemical Reaction, Atom by Atom, Bond by Bond

When Felix Fischer of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) set out to develop nanostructures made of graphene using a new, controlled approach to chemical reactions, the first result was a surprise: spectacular images of individual carbon atoms and the bonds between them.

“We weren’t thinking about making beautiful images; the reactions themselves were the goal,” says Fischer, a staff scientist in Berkeley Lab’s Materials Sciences Division (MSD) and a professor of chemistry at the University of California, Berkeley. “But to really see what was happening at the single-atom level we had to use a uniquely sensitive atomic force microscope in Michael Crommie’s laboratory.” Crommie is an MSD scientist and a professor of physics at UC Berkeley.

What the microscope showed the researchers, says Fischer, “was amazing.” The specific outcomes of the reaction were themselves unexpected, but the visual evidence was even more so. “Nobody has ever taken direct, single-bond-resolved images of individual molecules, right before and immediately after a complex organic reaction,” Fischer says.

The researchers report their results online in the May 30, 2013 edition of Science Express.

Nanotech and Berkeley

Where I work recently opened the newest facility at the Lab, The Molecular Foundry. It's a facility dedicated to researching nanotech and nanoscale science. The City of Berkeley, aka the People's Republic of Berkeley, requires a lot of paperwork whenever the Lab wants to build something. I mean a lot. So when we built the tMF, we complied with the construction codes. The article linked to above notes that Berkeley didn't have a clue about what we were doing and recently passed some stringent code wrt to nanotech. In some senses its understandable, but in others...the way Berkeley approached it:

“We sent them a bunch of questions, starting with: ‘What the heck is a nanoparticle?’ ” Mr. Al-Hadithy said.

*sighs*

That could have been answered without asking the Lab about it. I guess perhaps I am just one of those people that are aware enough of what's going on around him technowise that I knew the answer and perhaps it's just unfair of me to think this, but...where the heck has Berkeley been? Nanotech has been talked about in one form or another for over a decade and a half now! Then again, I have said before that Berkeley is that place that the Sixties didn't simply fade away. It must be a refugium! I do have to wonder what it will be like with the passing of the Boomers.