Our electronic devices are getting smaller and smaller while doing more and more. Using conventional materials, we will soon reach the practical limit. The electronics of tomorrow require alternatives, such as nanowires made of DNA that can serve as conductive paths and nanotransistors for miniature circuits. In the journal Angewandte Chemie, German scientists have now described a new method for the production of stable, conducting DNA nanowires.
DNA is more than a carrier of genetic information; it is also an interesting building material for nanotechnology. This is because of its extraordinary self-organizational properties. DNA is thus often used as a “mold” for the production of nanoscale structures. Its use in the assembly of electronic circuits is hampered by the fact that DNA is a very poor conductor of electricity. One way to get around this is by depositing metal onto the DNA strands.
Scientists at the RWTH Aachen and the University of Munich have now developed a new strategy for the controlled production and metallization of DNA nanostructures. Led by Ulrich Simon, the team used a DNA strand consisting of an immobilization sequence and a metallization sequence. Several such strands are strung together so that the resulting DNA is made of alternating sequences.
The immobilization sequence contains alkyne groups. These allow the DNA to be snapped into place on a silicon wafer coated with azide groups in what is known as a “click” reaction. The other DNA segment has two tasks: it is equipped with functional groups that cause the aggregation of silver particles and can also attach DNA strands to each other.
The DNA strands are stretched, deposited onto the wafers, and attached by the “click” reaction. During the subsequent metallization with silver particles, neighboring strands are simultaneously cross-linked to form multistrands. These have significantly higher structural stability than single strands. In the future, this method could also be used to integrate the DNA strands into programmable DNA architectures to allow for the positioning and binding of complex structures on prestructured substrates.
Deposition of the silver particles does not complete the metallization process. In a second step, which resembles the development of photographs, gold from a solution can be deposited onto the silver particles. Changing the duration of the gold deposition process allows for variation of the diameter of the resulting nanowires.
This new method allowed the scientists to obtain micrometer-long, electrically contactable nanowires that have potential for development into further miniaturized circuits.About the Author
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201202401
Ulrich Simon | Angewandte Chemie
Separating methane and CO2 will become more efficient
18.10.2017 | KU Leuven
Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences