Graphene in screening DNA
16 Aug 2010 by Evoluted New Media
A novel method to pull DNA through a graphene membrane in order to screen and sequence its code is being developed by researchers at Technische Universiteit Delft.
A novel method to pull DNA through a graphene membrane in order to screen and sequence its code is being developed by researchers at Technische Universiteit Delft.
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Artistic rendering of a DNA molecule traversing through a small hole made in an atomically thin layer of graphene that is located on a Si/SiN chip. Credit: Cees Dekker lab TU Delft / Tremani |
The researchers hope that they will be able to optically or electrically read a DNA molecule base by base as it is driven through a nanopore in the graphene membrane.
A team of researchers from the laboratory of Professor Cees Dekkers at the Kavli Institute of Nanoscience drilled nanoscale holes in a one-atom thick layer of graphene using a focussed electron beam. They then illustrated that they could pull a single DNA molecule – around 3 billion bases measuring a metre long – in water through the nanopore.
“DNA Molecules are driven through by an applied electric field,” Professor Dekkers told Laboratory News, “This drives a negatively charged DNA molecule from the negative to the positive pole.”
An electrical voltage is applied across the membrane, which leads to an ionic current through the nanopore as the ions in solution start the flow through. As the DNA nears the pore, it is attracted to it, and lessens the current as it passes through by partly blocks the flow of ions.
In principle, each base of the DNA could be sequenced as it flows through the nanopore in the membrane. “We have not actually read bases yet,” said Dekkers, “But the potential is to do so electrically or optically.”
Graphene offers new opportunities for DNA translocation – not just sequencing. It is ideally suited to the application and is an excellent conductor compared with SiN which is currently used.
