Researchers say carbon-based platform beats silicon for detection
7/26/2010 6:25 PM EDT
PORTLAND, Ore.—Carbon-based platforms outperform existing silicon-nitride based systems, according to a University of Pennsylvania team that is working on a system which automates DNA sequencing. With its carbon-based detectors, the team has been able to sense the electronic signatures of DNA strands with integrated graphene nanopores.
The graphene-based detector was fabricated at the University of Pennsylvania using chemical vapor deposition to grow flakes of graphene in which they drilled nanoscale pores with the electron beam of a transmission electron microscope.
The researchers were able to demonstrate that individual DNA strands could be coaxed into threading through the tiny graphene nanopores with electric fields. The process, called translocation, detects the components of a DNA strand (called bases) by sensing them with tiny electrodes as they glide through the graphene pore. Each DNA base, according to the researchers, can be distinguished by virtue of conducting with a slightly different current.
University of Pennsylvania researchers developed
a carbon-based, nanoscale platform to electrically detect single DNA molecules
by using electric fields to push tiny DNA strands through atomically-thin
graphene nanopores that ultimately may sequence DNA bases by their unique
Photo credit: Robert Johnson.
The carbon-based platform was found to significantly
boost the signal coming from the translocation electrodes, compared to
existing silicon nitride detectors.
Funding for the research was provided by the National Institutes of
Health, 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 the
Pennsylvania Department of Health.