ZDR researchers conduct electricity using DNA-based nanowires
Tinier than the AIDS virus – that is currently the circumference of the smallest transistors. The industry has shrunk the central elements of their computer chips to fourteen nanometers in the last sixty years. Conventional methods, however, are hitting physical boundaries. An alternative could be the self-organization of complex components from molecules and atoms. Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Paderborn University have now made an important advance: the physicists conducted a current through gold-plated nanowires, which independently assembled themselves from single DNA strands. Their results have been published in the scientific journal Langmuir.
At first glance, it resembles wormy lines in front of a black background. But what the electron microscope shows up close is that the nanometer-sized structures connect two electrical contacts. Dr. Artur Erbe from the Institute of Ion Beam Physics and Materials Research is pleased about what he sees. “Our measurements have shown that an electrical current is conducted through these tiny wires."
This is not necessarily self-evident, the physicist stresses. We are, after all, dealing with components made of modified DNA. In order to produce the nanowires, the researchers combined a long single strand of genetic material with shorter DNA segments through the base pairs to form a stable double strand. Using this method, the structures independently take on the desired form.
“With the help of this approach, which resembles the Japanese paper folding technique origami and is therefore referred to as DNA-origami, we can create tiny patterns," explains the HZDR researcher. “Extremely small circuits made of molecules and atoms are also conceivable here.”
This strategy, which scientists call the "bottom-up” method, aims to turn conventional production of electronic components on its head. “The industry has thus far been using what is known as the ‘top-down’ method. Large portions are cut away from the base material until the desired structure is achieved. Soon this will no longer be possible due to continual miniaturization.” The new approach is instead oriented on nature: molecules that develop complex structures through self-assembling processes.
Golden Bridges Between Electrodes
The elements that thereby develop would be substantially smaller than today’s tiniest computer chip components. Smaller circuits could theoretically be produced with less effort. There is, however, a problem: “Genetic matter doesn’t conduct a current particularly well,” points out Erbe. He and his colleagues have therefore placed gold-plated nanoparticles on the DNA wires using chemical bonds. Using a "top-down" method – electron beam lithography – they subsequently make contact with the individual wires electronically.
“This connection between the substantially larger electrodes and the individual DNA structures have come up against technical difficulties until now. By combining the two methods, we can resolve this issue. We could thus very precisely determine the charge transport through individual wires for the first time,” adds Erbe.
As the tests of the Dresden researchers have shown, a current is actually conducted through the gold-plated wires – it is, however, dependent on the ambient temperature. “The charge transport is simultaneously reduced as the temperature decreases,” describes Erbe. “At normal room temperature, the wires function well, even if the electrons must partially jump from one gold particle to the next because they haven't completely melded together.
The distance, however, is so small that it currently doesn’t even show up using the most advanced microscopes.” In order to improve the conduction, Artur Erbe’s team aims to incorporate conductive polymers between the gold particles. The physicist believes the metallization process could also still be improved.
He is, however, generally pleased with the results: “We could demonstrate that the gold-plated DNA wires conduct energy. We are actually still in the basic research phase, which is why we are using gold rather than a more cost-efficient metal. We have, nevertheless, made an important stride, which could make electronic devices based on DNA possible in the future.”
B. Teschome, S. Facsko, T. Schönherr, J. Kerbusch, A. Keller, A. Erbe: Temperature-Dependent Charge Transport through Individually Contacted DNA Origami-Based Au Nanowires, in Langmuir, 2016, 32 (40), pp 10159–10165 (DOI: 10.1021/acs.langmuir.6b01961)
Dr. Artur Erbe
Institute of Ion Beam Physics and Materials Research at HZDR
Phone +49 351 260-2366
Simon Schmitt | Science editor
Phone +49 351 260-3400 | Mail: email@example.com
Helmholtz-Zentrum Dresden-Rossendorf | Bautzner Landstr. 400 | 01328 Dresden | www.hzdr.de
The Helmholtz-Zentrum Dresden-Rossendorf (HZDR) conducts research in the sectors energy, health, and matter. It focuses its research on the following topics:
• How can energy and resources be used efficiently, safely, and sustainably?
• How can malignant tumors be visualized and characterized more precisely and treated effectively?
• How do matter and materials behave in strong fields and in the smallest dimensions?
The HZDR has been a member of the Helmholtz Association, Germany’s largest research organization, since 2011. It has five locations (Dresden, Grenoble, Freiberg, Leipzig, and Schenefeld) and employs about 1,100 people – approximately 500 of whom are scientists, including 150 doctoral candidates.
__Communication and Media Relations
Helmholtz-Zentrum Dresden-Rossendorf | Bautzner Landstr. 400 | 01328 Dresden
__HZDR at Facebook, Twitter and YouTube:
www.facebook.com/Helmholtz.Dresden, www.twitter.com/hzdr_dresden und www.youtube.com/user/FZDresden
Simon Schmitt | Helmholtz-Zentrum Dresden-Rossendorf
Microscopic trampoline may help create networks of quantum computers
17.07.2018 | University of Colorado at Boulder
Electronic stickers to streamline large-scale 'internet of things'
17.07.2018 | Purdue University
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...
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...
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...
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....
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...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Life Sciences
17.07.2018 | Information Technology
17.07.2018 | Power and Electrical Engineering