As mentioned in my previous article, two groups, from Upenn and Netherlands, have already put this idea into practice. They really drill a nanopore on the sheets of graphene!!
both of them have been published in Nano Letters,
This one is from a famous group in the field of biosensor lead by Cees Dekker
And this one is from Upenn, Datta's previous lab lead by A.T. Charlie Johnson, they are the pioneer that found a way to sense the gas odor by DNA-decorated carbon nanotube
They realized this idea by recording the blocked current change while the DNA were passing through these holes, and they found the current change profile corresponding to the two states of DNA; the signals could be used to distinguish the DNA either folded or unfolded as it pass through a pore. These DNAs were driven by a potential difference across the graphene membrane, which allows the measurement of the passing of DNA.
In my view, it is not dfficult to imagine that the ion distribution outside the giant biomolecules such as DNA and protein would somehow change to adapt these intruders and tend to maintain charge neutrality in the solution. As these molecules approach the surface of graphene, the graphene nanopore device can detect this considerable or even quantitative change in ionic condition in terms of the pulses that decrease in current. I believe that it is just the first step for DNA sequencing. The difficulty of this final goal is possible to be limited to rate of detection, since the transient signal is hard to be used in distinguishing the single-base pair differences.
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