We report a tight-binding model study of two-terminal graphene nanopore based
device, for sequential determination of DNA bases. Using Greens function
approach we calculate conductance spectra, I-V response and also the changes in
local density of states (LDOS) profile as four different nucleobases inserted
one by one into the pore embedded in the zigzag graphene nanoribbon (ZGNR). We
find distinct features in LDOS profile for different nucleotides and the same
is also present in conductance and I-V response. We propose the actual working
principle of the device, by setting the bias across the pore to a fixed voltage
(this voltage gives maximum discrimination between characteristic current of
the four nucleotides) and translocating the ss-DNA through the nanopore using a
transverse electric field while recording the characteristic current of the
nucleotides. Not only the typical current output is much larger than previous
results, but the seaparation between them for different bases are also
definite. Our investigation provides high accuracy and significant amount of
distinction between different nucleotides.Comment: 6 pages, 5 figure