Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DNA nano-foundries cast custom-shaped metal nanoparticles

10.10.2014

DNA's programmable assembly is leveraged to form precise 3D nanomaterials for disease detection, environmental testing, electronics and beyond

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 concept of casting nanoparticles inside DNA molds is very much alike the Japanese method of growing watermelons inside cube-shaped glass boxes. Credit: Harvard's Wyss Institute / Peng Yin


By creating molds from stiff DNA, researchers were able to cast gold "seeds" into complex metal nanoparticles. From left to right, this 3D polygonal particle was formed by designing a DNA mold, planting a gold seed, then chemically forcing the seed to expand until complete formation. Credit: Harvard's Wyss Institute

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.

A very useful property is that once cast, these nanoparticles can retain the framework of the DNA mold as an outer coating, enabling additional surface modification with impressive nanoscale precision. These coatings can also help scientists develop highly-sensitive, multiplex methods of detecting early–stage cancers and genetic diseases by combining the chemical specificity of the DNA with the signal readout of the metal. For particles that would better serve their purpose by being as electrically conducive as possible, such as in very small nanocomputers and electronic circuitry, the DNA framework coating is quickly and easily broken down and removed to produce pure metal wires and connectors.

"The properties of DNA that allow it to self assemble and encode the building blocks of life have been harnessed, re–purposed and re–imagined for the nano–manufacturing of inorganic materials," said Don Ingber, Wyss Institute founding director. "This capability should open up entirely new strategies for fields ranging from computer miniaturization to energy and pathogen detection."

MEDIA CONTACT

Wyss Institute for Biologically Inspired Engineering at Harvard University
Kat J. McAlpine, katherine.mcalpine@wyss.harvard.edu, +1 617-432-8266

About the Wyss Institute for Biologically Inspired Engineering at Harvard University

The Wyss Institute for Biologically Inspired Engineering at Harvard University (http://wyss.harvard.edu) uses Nature's design principles to develop bioinspired materials and devices that will transform medicine and create a more sustainable world. Working as an alliance among all of Harvard's Schools, and in partnership with Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, Boston Children's Hospital, Dana Farber Cancer Institute, Massachusetts General Hospital, the University of Massachusetts Medical School, Spaulding Rehabilitation Hospital, Boston University, Tufts University, and Charité - Universitätsmedizin Berlin, and the University of Zurich, the Institute crosses disciplinary and institutional barriers to engage in high-risk research that leads to transformative technological breakthroughs. By emulating Nature's principles for self-organizing and self-regulating, Wyss researchers are developing innovative new engineering solutions for healthcare, energy, architecture, robotics, and manufacturing. These technologies are translated into commercial products and therapies through collaborations with clinical investigators, corporate alliances, and new start-ups.

Kat McAlpine | Eurek Alert!
Further information:
http://wyss.harvard.edu/viewpressrelease/170/dna-nanofoundries-cast-customshaped-metal-nanoparticles

More articles from Life Sciences:

nachricht Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung

nachricht Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>