Anuj Girdhar, Chaitanya Sathe, Klaus Schulten, and Jean-Pierre Leburton.
Graphene quantum point contact transistor for DNA sensing.
Proceedings of the National Academy of Sciences, USA,
110:16748-16753, 2013.
GIRD2013
By using the Non-Equilibrium Green’s Function technique we show that the shape of the
edge, the carrier concentration, and the position and size of a nanopore in graphene
nanoribbons can strongly affect its electronic conductance as well as its sensitivity to
external charges. This technique, combined with a self-consistent Poisson-Boltzmann
formalism to account for ion charge screening in solution, is able to detect the rotational
and positional conformation of a DNA strand inside the nanopore. In particular, we show
that a graphene membrane with quantum point contact (QPC) geometry exhibits greater
electrical sensitivity than a uniform armchair geometry provided that the carrier
concentration is tuned to enhance charge detection. We propose a membrane design
that contains an electrical gate in a configuration similar to a field effect transistor for a
graphene-based DNA sensing device.
