Corporate Banner
Satellite Banner
qPCR
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Graphene Nanoribbons for “Reading” DNA

Published: Tuesday, November 19, 2013
Last Updated: Tuesday, November 19, 2013
Bookmark and Share
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.

EPFL researchers have found a way to improve this technique by using a material with unique properties: graphene.

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.

A thickness of one third of a nanometer
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.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,500+ scientific posters on ePosters
  • More than 5,000+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.


Scientific News
Point of Care Diagnostics - A Cautious Revolution
Advances in molecular biology, coupled with the miniaturization and improved sensitivity of assays and devices in general, have enabled a new wave of point-of-care (POC) or “bedside” diagnostics.
Analysing 10,000 Cells Simultaneously
New techniquethat traps 10,000 cells on a single chip has potential for cancer screening for individuals.
$1M NIH Grant to Refine PCR Based Cancer Test
Researchers at Cornell University, Weill Cornell Medicine, the University of California, San Francisco, and the Infectious Diseases Institute in Kampala, Uganda, recieve a four-year, $1 million grant to hone technology for a quick, in-the-field diagnosis of Kaposi's sarcoma — a cancer frequently related to HIV infections.
Genetic Tug of War Before Cells Decide Fate
Researchers report that as developing blood cells are triggered by genetic signals firing on and off, a 'tug of war' occurs.
Linkage Biosciences Awarded NHS Contract
Comapny announces that it has been awarded a four-year contract by NHS Blood and Transplant (NHSBT) in the UK for implementation of the LinkSeq™ Real-Time PCR HLA typing product.
Understanding Tumor Evolution
Study provides insight into tumor evolution; may point to improved diagnosis and treatment.
Frankfurter Fraud: Finding Out What’s In Your Hot Dog
Scientists have developed a technique to test the meat content of Frankfurters.
How Cloud Connectivity Can Combat the Reproducibility Crisis
This infographic explains the reproducibility crisis, and how cloud connectivity can help overcome this problem.
Keeping Cells in Shape to Fight Sepsis
Boosting levels of a protein that controls the shape and activity of a crucial group of white blood cells improves survival and recovery chances during sepsis.
This 3D Printer Can Detect Infectious Diseases
Researchers at AI Biosciences, Inc. have repurposed 3D printers into machines capable of performing sample preparation and DNA amplification.

SELECTBIO Market Reports
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,000+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!