  Graphene nanopore based sensor devices are exhibiting the great potential for
the detection of DNA. To understand the fundamental aspects of DNA
translocating through a graphene nanopore, in this work, molecular dynamics
(MD) simulations and potential of mean force (PMF) calculations were carried
out to investigate the layer impact of small graphene nanopore (2 nm-3 nm) to
DNA translocation. It was observed that the ionic conductance was sensitive to
graphene layer of open-nanopores, the probability for DNA translocation through
graphene nanopore was related with the thickness of graphene nanopores. MD
simulations showed that DNA translocation time was most sensitive to the
thickness of graphene nanopore for a 2.4 nm aperture, and the observed free
energy barrier of PMFs and the profile change revealed the increased
retardation of DNA translocation through bilayer graphene nanopore as compared
to monolayer graphene nanopore.
