Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Penn Researchers Provide First Step Towards Electronic DNA Sequencing: Translocation Through Graphene Nanopores

University of Pennsylvania researchers developed a carbon-based, nanoscale platform to electrically detect single DNA molecules. Electric fields push tiny DNA strands through atomically-thin graphene nanopores that ultimately may sequence DNA bases by their unique electrical signature. (Photo: Robert Johnson)
University of Pennsylvania researchers developed a carbon-based, nanoscale platform to electrically detect single DNA molecules. Electric fields push tiny DNA strands through atomically-thin graphene nanopores that ultimately may sequence DNA bases by their unique electrical signature. (Photo: Robert Johnson)

Abstract:
Researchers at the University of Pennsylvania have developed a new, carbon-based nanoscale platform to electrically detect single DNA molecules

Penn Researchers Provide First Step Towards Electronic DNA Sequencing: Translocation Through Graphene Nanopores

Philadelphia, PA | Posted on July 25th, 2010

Using electric fields, the tiny DNA strands are pushed through nanoscale-sized, atomically thin pores in a graphene nanopore platform that ultimately may be important for fast electronic sequencing of the four chemical bases of DNA based on their unique electrical signature.

The pores, burned into graphene membranes using electron beam technology, provide Penn physicists with electronic measurements of the translocation of DNA.

The article, submitted on March 25, is published in the current issue of Nano Letters.

"We were motivated to exploit the unique properties of graphene a two-dimensional sheet of carbon atoms in order to develop a new nanopore electrical platform that could exhibit high resolution," said Marija Drndić, associate professor in the Department of Physics and Astronomy in Penn's School of Arts and Sciences and the paper's senior author. "High resolution of graphene nanopore devices is expected because the thickness of the graphene sheet is smaller than the distance between two DNA bases. Graphene has previously been used for other electrical and mechanical devices, but up until now it has not been used for DNA translocation."

The research team had made graphene nanopores in a study completed two years ago and in this study put the pores to work.

To conduct the experiments, Drndić and postdoctoral fellow Christopher A. Merchant, together with Ken Healy, Meni Wanunu, Vishva Ray and other members from the Drndić lab made use of large-area graphene material developed by postdoctoral fellow Zhengtang Luo and Professor A.T. Charlie Johnson, both physicists at Penn. The team used a chemical vapor deposition, or CVD, method to grow large flakes of graphene and suspend them over a single micron-sized hole made in silicon nitride. An even smaller hole, the nanopore in the very center of the suspended graphene, was then drilled with an electron beam of a transmission electron microscope, or TEM.

Solid-state nanopores are proving to be invaluable tools for probing biology at the single-molecule level.

Graphene nanopore devices developed by the Penn team work in a simple manner. The pore divides two chambers of electrolyte solution and researchers apply voltage, which drives ions through the pores. Ion transport is measured as a current flowing from the voltage source. DNA molecules, inserted into the electrolyte, can be driven single file through such nanopores.

As the molecules translocate, they block the flow of ions and are detected as a drop in the measured current. Because the four DNA bases block the current differently, graphene nanopores with sub-nanometer thickness may provide a way to distinguish among bases, realizing a low-cost, high-throughput DNA sequencing technique.

In addition, to increase the robustness of graphene nanopore devices, Penn researchers also deposited an ultrathin layer, only a few atomic layers thick, of titanium oxide on the membrane which further generated a cleaner, more easily wettable surface that allows the DNA to go through it more easily. Although graphene-only nanopores can be used for translocating DNA, coating the graphene membranes with a layer of oxide consistently reduced the nanopore noise level and at the same time improved the robustness of the device.

Because of the ultrathin nature of the graphene pores, researchers were able to detect an increase in the magnitude of the translocation signals relative to previous solid state nanopores made in silicon nitride, for similar applied voltages.

The Penn team is now working on improving the overall reliability of these devices and on utilizing the conductivity of the graphene sheet to create devices with transverse electrical control over DNA transport. Specifically, this transverse electrical control may be achievable by carving graphene into nanoelectrodes and utilizing its conducting nature. Towards this goal, Michael Fischbein and Drndic have previously demonstrated nanosculpting of graphene into arbitrary structures, such as nanoribbons, nanopores and other shapes, published in Applied Physics Letters in 2008, creating a firm foundation for future research.

Research was conducted by Merchant, Healy, Wanunu, Ray, Neil Peterman, John Bartel, Michael D. Fischbein, Kimberly Venta, Luo, Johnson and Drndić of Penn's Department of Physics and Astronomy.

The research was supported by a National Institutes of Health grant and also grants from the U.S. Department of Defense, Army Research Office, Penn Genome Frontiers Institute, Nano-Bio Interface Center at Penn, Nanotechnology Institute of the Commonwealth of Pennsylvania and Pennsylvania Department of Health. The Department of Health specifically disclaims responsibility for any analyses, interpretations or conclusions.

####

For more information, please click here

Contacts:
Media Contact:
Jordan Reese

215-573-6604

Copyright © University of Pennsylvania

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

From allergens to anodes: Pollen derived battery electrodes February 8th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

Canadian physicists discover new properties of superconductivity February 8th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

From allergens to anodes: Pollen derived battery electrodes February 8th, 2016

Possible Futures

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Scientists create laser-activated superconductor February 8th, 2016

Nanoscale cavity strongly links quantum particles: Single photons can quickly modify individual electrons embedded in a semiconductor chip and vice versa February 8th, 2016

A fast solidification process makes material crackle February 8th, 2016

Academic/Education

COD Grad Begins Postdoctoral Fellow at Harvard University: Marsela Jorgolli's Passion for Physics Has Led to a Decade of Academic Research That Continues at Harvard University as a Postdoctoral Fellow February 2nd, 2016

Heriot-Watt's Institute of Photonics & Quantum Sciences uses the Deben Microtest 2 kN tensile stage to characterise ceramics and engineering plastics January 21st, 2016

Multiple uses for the JPK NanoWizard AFM system in the Smart Interfaces in Environmental Nanotechnology Group at the University of Illinois at Urbana-Champaign January 20th, 2016

BioSolar Extends Research Agreement With UCSB for Next Phase of Its Super Battery Technology: Development Effort to Continue Under the Supervision of Nobel Laureate, Dr. Alan Heeger January 13th, 2016

Nanotubes/Buckyballs/Fullerenes

The iron stepping stones to better wearable tech without semiconductors February 8th, 2016

Nano-coating makes coaxial cables lighter: Rice University scientists replace metal with carbon nanotubes for aerospace use January 28th, 2016

Scientists provide new guideline for synthesis of fullerene electron acceptors January 28th, 2016

Nanostructural Changes in Solar Cells to Increase Their Efficiency January 28th, 2016

Nanomedicine

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

UTHealth research looks at nanotechnology to help prevent preterm birth February 7th, 2016

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Announcements

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

A fast solidification process makes material crackle February 8th, 2016

From allergens to anodes: Pollen derived battery electrodes February 8th, 2016

Nanobiotechnology

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

UTHealth research looks at nanotechnology to help prevent preterm birth February 7th, 2016

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic