2 research outputs found
Effects of Graphene Nanopore Geometry on DNA Sequencing
In
this Letter we assess the effect of graphene nanopore geometries
on DNA sequencing by considering DNA fragments including A, T, C,
G, and 5-methylcytosine (MC) pulled out of graphene nanopores of different
geometries with diameters down to ∼1 nm. Using steered molecular
dynamics simulations it is demonstrated that the bases (A, T, C, G,
and MC) can be indentified at single-base resolution through the characteristic
peaks on the force profile in a circular graphene nanopore but not
in nanopores with other asymmetric geometries. Our study suggests
that the graphene nanopore surface should be modified as symmetrically
as possible in order to sequence DNA by atomic force microscopy or
optical tweezers
Separation of Hydrogen Gas from Coal Gas by Graphene Nanopores
We designed a series of porous graphene
as the separation membrane
for hydrogen gas in coal gas. The permeation process of different
gas molecules (H<sub>2</sub>, CO, CH<sub>4</sub>, and H<sub>2</sub>S) in porous graphene was evaluated under the atmospheric pressure
and high pressure conditions. Our results indicate the hydrogen permeability
and selectivity could be tuned by the size and the shape of the porous
graphene. For graphene with bigger pores, the selectivity for hydrogen
gas could decrease. In the porous graphene with same pore area, the
hydrogen gas selectivity could be affected by the shape of the pore.
The potential of mean force (PMF) of different gases to pass through
a good separation candidate was calculated. The order of PMF for different
gases to pass through the good separation candidate is H<sub>2</sub> < CO < CH<sub>4</sub> ≈ H<sub>2</sub>S, which is also
confirmed by the first-principle density function theory (DFT) calculation