Technique Devised for Controlling Graphene Nanopore Size

Moon Kim (University of Texas – Dallas)

Materials scientists at University of Texas in Dallas and Gwangju Institute of Science and Technology in Korea developed a process for making the size of nanopores in the material graphene small enough to read a single strand of DNA. The discovery is outlined in a recent issue of the journal Carbon (paid subscription required).

The research team led by UT-Dallas materials scientist Moon Kim (pictured left) studied the properties of graphene to expand or contract the pores in the material. Graphene is closely related to graphite like that used in pencils, but consists of only a single atomic layer of carbon atoms. The material is very light, strong, chemically stable, and can conduct both heat and electricity.

Because of these properties, Kim and colleagues aimed to find a method for controlling the size of graphene pores to a size small enough to filter a single strand of DNA, narrower than one nanometer — one nanometer equals one billionth of a meter. With that capability, a sheet of graphene could be configured into medical devices to analyze the sequence of DNA samples at a much lower cost than today.

Kim’s team found they could shrink nanopores in graphene under electron beam irradiation at temperatures of 400 to 1,200 C, but the nanopores would close completely. They found and demonstrated, however, that the nanopore shrinking process under these conditions can be stopped by blocking the electron beam.

Kim says this is the first time that the graphene nanopore has been controlled, especially through shrinking. “We used high temperature heating and electron beam simultaneously,” notes Kim, “one technique without the other doesn’t work.”

The next stage for the researchers is to build a prototype device incorporating their process, with an eye on DNA sequencing applications. “If we could sequence DNA cheaply, the possibilities for disease prevention, diagnosis and treatment would be limitless,” says Kim. “Controlling graphene puts us one step closer to making this happen.”

Read more:

• Nanotech Process Devised for Graphene Semiconductors
• Method Devised for Inexpensive Graphene Production
• Graphene-Based Nanotech Gas Detector Developed
• U.K. Company Licenses Harvard Graphene DNA Technology

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