Featured Research

from universities, journals, and other organizations

Graphene nanoribbons for 'reading' DNA: Researchers improve the nanopore-based technology for detecting DNA molecules

Date:
November 17, 2013
Source:
Ecole Polytechnique Fédérale de Lausanne
Summary:
One of the methods used for examining the molecules in a liquid consists in passing the fluid through a nano-sized hole so as to detect their passage. Researchers have found a way to improve this technique by using a material with unique properties: graphene.

Many efforts over last decade have been directed towards development of single molecule sequencing based on solid state nanopores. Aleksandra Radenovic and co-workers have made a device composed of a graphene nanoribbon transistor built on top of a solid state nanopore. Direct electrical readout from the graphene transistors is used to detect DNA translocation events. Nanopore, DNA and the graphene nanoribbon are shown in this schematic (which is not to scale).
Credit: EPFL

If we wanted to count the number of people in a crowd, we could make on the fly estimates, very likely to be imprecise, or we could ask each person to pass through a turnstile. The latter resembles the model that EPFL researchers have used for creating a "DNA reader" that is able to detect the passage of individual DNA molecules through a tiny hole: a nanopore with integrated graphene transistor.

The DNA molecules are diluted in a solution containing ions and are driven by an electric field through a membrane with a nanopore. When the molecule goes through the orifice, it provokes a slight perturbation to the field, detectable not only by the modulations in ionic current but also by concomitant modulation in the graphene transistor current. Based on this information, it is possible to determine whether a DNA molecule has passed through the membrane or not.

This system is based on a method that has been known for over a dozen years. The original technique was not as reliable since it presented a number of shortcomings such as clogging pores and lack of precision, among others. "We thought that we would be able to solve these problems by creating a membrane as thin as possible while maintaining the orifice's strength," said Aleksandra Radenovic from the Laboratory of Nanoscale Biology at EPFL. Together with Floriano Traversi, postdoctoral student, and colleagues from the Laboratory of Nanoscale Electronics and Structures, she came across the material that turned out to be both the strongest and most resilient: graphene, which consists of a single layer of carbon molecules. The strips of graphene or nanoribbons used in the experiment were produced at EPFL, thanks to the work carried out at the Center for Micro Nanotechnology (CMI) and the Center for Electron Microscopy (CIME).

"Through an amazing coincidence, continued the researcher, the graphene layer's thickness measures 0.335 nm, which exactly fits the gap existing between two DNA bases, whereas in the materials used so far there was a 15 nm thickness." As a result, while previously it was not possible to individually analyze the passage of DNA bases through these "long" tunnels -- at a molecular scale -, the new method is likely to provide a much higher precision. Eventually, it could be used for DNA sequencing.

However they are not there yet. In only 5 milliseconds, up to 50'000 DNA bases can pass through the pores. The electric output signal is not clear enough for "reading" the live sequence of the DNA strand passage. "However, the possibility of detecting the passage of DNA with graphene nanoribbons is a breakthrough as well as a significant opportunity," said Aleksandra Radenovic. She noted that, for example, the device is also able to detect the passage of other kinds of proteins and provide information on their size and/or shape.

This crucial step towards new methods of molecular analysis has received an ERC grant and is featured in an article published today in Nature Nanotechnology.


Story Source:

The above story is based on materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Materials may be edited for content and length.


Journal Reference:

  1. F. Traversi, C. Raillon, S. M. Benameur, K. Liu, S. Khlybov, M. Tosun, D. Krasnozhon, A. Kis, A. Radenovic. Detecting the translocation of DNA through a nanopore using graphene nanoribbons. Nature Nanotechnology, 2013; DOI: 10.1038/nnano.2013.240

Cite This Page:

Ecole Polytechnique Fédérale de Lausanne. "Graphene nanoribbons for 'reading' DNA: Researchers improve the nanopore-based technology for detecting DNA molecules." ScienceDaily. ScienceDaily, 17 November 2013. <www.sciencedaily.com/releases/2013/11/131117155615.htm>.
Ecole Polytechnique Fédérale de Lausanne. (2013, November 17). Graphene nanoribbons for 'reading' DNA: Researchers improve the nanopore-based technology for detecting DNA molecules. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2013/11/131117155615.htm
Ecole Polytechnique Fédérale de Lausanne. "Graphene nanoribbons for 'reading' DNA: Researchers improve the nanopore-based technology for detecting DNA molecules." ScienceDaily. www.sciencedaily.com/releases/2013/11/131117155615.htm (accessed October 20, 2014).

Share This



More Matter & Energy News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) — Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) — Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) — Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) — Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins