Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tailored DNA shifts electrons into the 'fast lane'

21.06.2016

DNA nanowire improved by altering sequences

DNA molecules don't just code our genetic instructions. They can also conduct electricity and self-assemble into well-defined shapes, making them potential candidates for building low-cost nanoelectronic devices.


Each ribboning strand of DNA in our bodies is built from stacks of four molecular bases, shown here as blocks of yellow, green, blue and orange, whose sequence encodes detailed operating instructions for the cell. New research shows that tinkering with the order of these bases can also be used to tune the electrical conductivity of nanowires made from DNA.

Credit: Maggie Bartlett, NHGRI

A team of researchers from Duke University and Arizona State University has shown how specific DNA sequences can turn these spiral-shaped molecules into electron "highways," allowing electricity to more easily flow through the strand.

The results may provide a framework for engineering more stable, efficient and tunable DNA nanoscale devices, and for understanding how DNA conductivity might be used to identify gene damage. The study appears online June 20 in Nature Chemistry.

Scientists have long disagreed over exactly how electrons travel along strands of DNA, says David N. Beratan, professor of chemistry at Duke University and leader of the Duke team. Over longer distances, they believe electrons travel along DNA strands like particles, "hopping" from one molecular base or "unit" to the next. Over shorter distances, the electrons use their wave character, being shared or "smeared out" over multiple bases at once.

But recent experiments lead by Nongjian Tao, professor of electrical engineering at Arizona State University and co-author on the study, provided hints that this wave-like behavior could be extended to longer distances.

This result was intriguing, says Duke graduate student and study lead author Chaoren Liu, because electrons that travel in waves are essentially entering the "fast lane," moving with more efficiency than those that hop.

"In our studies, we first wanted to confirm that this wave-like behavior actually existed over these lengths," Liu said. "And second, we wanted to understand the mechanism so that we could make this wave-like behavior stronger or extend it to even longer distances."

DNA strands are built like chains, with each link comprising one of four molecular bases whose sequence codes the genetic instructions for our cells. Using computer simulations, Beratan's team found that manipulating these same sequences could tune the degree of electron sharing between bases, leading to wave-like behavior over longer or shorter distances. In particular, they found that alternating blocks of five guanine (G) bases on opposite DNA strands created the best construct for long-range wave-like electronic motions.

The team theorizes that creating these blocks of G bases causes them to all "lock" together so the wave-like behavior of the electrons is less likely to be disrupted by random wiggling in the DNA strand.

"We can think of the bases being effectively linked together so they all move as one," Liu said. "This helps the electron be shared within the blocks."

The Tao group confirmed these theoretical predictions using break junction experiments, tethering short DNA strands built from alternating blocks of three to eight guanine bases between two gold electrodes and measuring the amount of electrical charge flowing through the molecules.

The results shed light on a long-standing controversy over the exact nature of the electron transport in DNA, Beratan says. They might also provide insight into the design of tunable DNA nanoelectronics, and into the role of DNA electron transport in biological systems.

"This theoretical framework shows us that the exact sequence of the DNA helps dictate whether electrons might travel like particles, and when they might travel like waves," Beratan said. "You could say we are engineering the wave-like personality of the electron."

###

Other authors include Yuqi Zhang and Peng Zhang of Duke University and Limin Xiang and Yueqi Li of Arizona State University.

This research was supported by grants from the Office of Naval Research (N00014-11-1-0729) and the National Science Foundation (DMR-1413257).

CITATION: "Engineering nanometer-scale coherence in soft matter," Chaoren Liu, Yuqi Zhang, Peng Zhang, David N. Beratan, Limin Xiang, Yueqi Li, Nongjian Tao. Nature Chemistry, June 20, 2016. DOI: 10.1038/nchem.2545

Media Contact

Kara J. Manke
kara.manke@duke.edu
919-681-8064

 @DukeU

http://www.duke.edu 

Kara J. Manke | EurekAlert!

Further reports about: DNA DNA strands Electrons electricity genetic instructions sequences waves

More articles from Life Sciences:

nachricht Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital

nachricht New insights into the information processing of motor neurons
22.02.2017 | Max Planck Florida Institute for Neuroscience

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>