Graphene outperforms silicon nitride in automated DNA sequencing

Carbon-based platforms can outperform existing silicon nitride systems, according to University of Pennsylvania researchers working on a system that automates DNA sequencing. Using carbon-based detectors, the team has been able to sense the electronic signatures of DNA strands through the use of integrated graphene nanopores.

The graphene-based detector was fabricated using chemical vapor deposition to grow flakes of graphene in which the researchers drilled nanoscale pores using the electron beam of a transmission electron microscope.

The researchers claim they demonstrated that individual DNA strands could be coaxed into threading through the tiny graphene nanopores using electric fields. The process, called translocation, detects the components of a DNA strand (called bases) by sensing them with tiny electrodes as they glide through the graphene pore. Each DNA base, according to the researchers, can be distinguished by virtue of conducting with a slightly different current.

The carbon-based platform was found to significantly boost signals coming from the translocation electrodes, compared to existing siicon nitride detectors.

- R. Colin Johnson
EE Times