In recent years graphene has astonished the scientific community with its many unique properties and potential applications, ranging from electronics and solar energy research to medical applications.
Jing Kong, also a co-author on the paper, and her colleagues at MIT first developed a method for the large-scale growth of graphene films that was used in the work.
The graphene was stretched over a silicon-based frame, and inserted between two separate liquid reservoirs. An electrical voltage applied between the reservoirs pushed the ions towards graphene membrane. When a nanopore was drilled through the membrane, this voltage channeled the flow of ions through the pore and registered as an electrical current signal.
When the researchers added long DNA chains in the liquid, they were electrically pulled one by one through the graphene nanopore. As the DNA molecule threads the nanopore, it blocks the flow of ions, resulting in a characteristic electrical signal that reflects the size and conformation of the DNA molecule.
Co-author Daniel Branton, Higgins Professor of Biology, Emeritus at Harvard, is one of the researches who, more than a decade ago, initiated the use of nanopores in artificial membranes to detect and characterize single molecules of DNA.
Together with his colleague David Deamer at the University of California, Branton suggested that nanopores might be used to quickly read the genetic code, much as one reads the data from a ticker-tape machine.
As a DNA chain passes through the nanopore, the nucleobases, which are the letters of the genetic code, can be identified. But a nanopore in graphene is the first nanopore short enough to distinguish between two closely neighboring nucleobases.
Several challenges still remain to be overcome before a nanopore
|Contact: Michael Patrick Rutter|