Nanotechnology Now







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

New method allows for greater variation in band gap tunability: The method can change a material's electronic band gap by up to 200 percent January 31st, 2015

Evidence mounts for quantum criticality theory: Findings bolster theory that quantum fluctuations drive strange electronic phenomena January 30th, 2015

Everything You Need To Know About Nanopesticides January 30th, 2015

DNA nanoswitches reveal how life's molecules connect: An accessible new way to study molecular interactions could lower cost and time associated with discovering new drugs January 30th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Evidence mounts for quantum criticality theory: Findings bolster theory that quantum fluctuations drive strange electronic phenomena January 30th, 2015

Nanoscale Mirrored Cavities Amplify, Connect Quantum Memories: Advance could lead to quantum computing and the secure transfer of information over long-distance fiber optic networks January 28th, 2015

Detecting chemical weapons with a color-changing film January 28th, 2015

'Bulletproof' battery: Kevlar membrane for safer, thinner lithium rechargeables January 28th, 2015

Possible Futures

GS7 Graphene Sensor maybe Solution in Fight Against Cancer January 25th, 2015

Nanotechnology in Energy Applications Market Research Report 2014-2018: Radiant Insights, Inc January 15th, 2015

'Mind the gap' between atomically thin materials December 23rd, 2014

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Academic/Education

Rice's Naomi Halas to direct Smalley Institute: Optics pioneer will lead Rice's multidisciplinary science institute January 15th, 2015

SUNY Board Appoints Dr. Alain Kaloyeros as Founding President of SUNY Polytechnic Institute January 13th, 2015

CNSE's Smart System Technology & Commercialization Center Successfully Recertifies as ISO 9001:2008 January 12th, 2015

SUNY Poly Now Accepting Applications to the Colleges of Nanoscale Science and Engineering for Fall 2015: Full Scholarships Available to Incoming CNSE Students January 7th, 2015

Nanotubes/Buckyballs

Chromium-centered cycloparaphenylene rings for making functionalized nanocarbons January 26th, 2015

GS7 Graphene Sensor maybe Solution in Fight Against Cancer January 25th, 2015

Toyocolor to Launch New Carbon Nanotube Materials at nano tech 2015 January 24th, 2015

Carbon nanotube finding could lead to flexible electronics with longer battery life January 14th, 2015

Nanomedicine

DNA nanoswitches reveal how life's molecules connect: An accessible new way to study molecular interactions could lower cost and time associated with discovering new drugs January 30th, 2015

Made-in-Singapore rapid test kit detects dengue antibodies from saliva: IBN's MedTech innovation simplifies diagnosis of infectious diseases January 29th, 2015

Iranian Researchers Planning to Produce Edible Insulin January 28th, 2015

Nanoparticles that deliver oligonucleotide drugs into cells described in Nucleic Acid Therapeutics January 28th, 2015

Announcements

New method allows for greater variation in band gap tunability: The method can change a material's electronic band gap by up to 200 percent January 31st, 2015

Evidence mounts for quantum criticality theory: Findings bolster theory that quantum fluctuations drive strange electronic phenomena January 30th, 2015

Everything You Need To Know About Nanopesticides January 30th, 2015

DNA nanoswitches reveal how life's molecules connect: An accessible new way to study molecular interactions could lower cost and time associated with discovering new drugs January 30th, 2015

Nanobiotechnology

DNA nanoswitches reveal how life's molecules connect: An accessible new way to study molecular interactions could lower cost and time associated with discovering new drugs January 30th, 2015

Spider electro-combs its sticky nano-filaments January 28th, 2015

Nanoshuttle wear and tear: It's the mileage, not the age January 26th, 2015

Engineering self-assembling amyloid fibers January 26th, 2015

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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE