Sep 18, 2013
Graphene nanonets make biological sensors
Researchers in Korea have developed a new and easy method to produce graphene nanonet (GNN) patterns over a large surface area by using selectively assembled V2O5 nanowires as a shadow mask on a graphene layer during a reactive ion etching step. The patterns, which contain continuous networks of chemically functionalized graphene nanoribbons, could be used to make biosensor devices.
Various graphene-based devices including those made from graphene oxide (GO) and graphene nanoribbons (GNRs) for biological sensing applications have been developed by many research groups around the world. However, it is difficult to functionalize pristine graphene with chemical or biological molecules. Furthermore, the low transconductance of the GO is a drawback in applications for active devices such as field effect transistor (FET) sensors. It also can be very time-consuming and complicated to fabricate large-scale networks of GNRs via conventional methods such as e-beam lithography shadow mask patterning processes.
A team led by Seounghun Hong in the Department of Physics at Seoul National University may now have gone some way in overcoming these problems and has succeeded in producing large-scale patterns of GNN structures made up of continuous networks of GNRs with chemical functional groups on their edges. The chemical functional groups in the GNN can be functionalized with biological molecules such as DNA for biochip applications.
Indeed, the group, which includes researchers from Pohang University of Science and Technology and Soonchunhyang University, has already successfully performed fluorescence imaging of DNA molecules on the GNN channels and has electrically detected the DNA at 1 nM concentrations using the GNN-based biochip devices.
The fabrication technique described in this work could be a powerful strategy to mass-produce GNR-based devices and should open up a host of practical applications.
More information can be found in the journal Nanotechnology 24 375302.
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End-contacted graphene nanoribbons outperform side-contacted ones (Apr 2012)
Can graphene ribbons be used for electronics? (Nov 2010)
Making narrow nanoribbons the easy way (Aug 2013)
Nanoribbons make good memories (Nov 2010)
About the author
Dr Taekyeong Kim was a PhD candidate under the supervision of Professor Seounghun Hong in the Department of Physics at Seoul National University. His research focused on the self-assembly of nanostructures for optical and biological sensor applications. Seunghun Hong’s research group has been working on hybrid devices made of nanostructures and conventional electronics for nanoelectronics applications and biological detection.