Simulation of Electronic Sensing of Biomolecules in Translocation Through a Nanopore in a Semiconductor Membrane - Nanopores: Sensing and Fundamental Biological Interactions - page 162

Fig. 7.5 Voltage signals on the two electrodes for a single-stranded DNA poly(dC) 20 passing
through the nanopore (in angstroms): (a) upper electrode voltage signal, (b) lower electrode
voltage signal, and (c) voltage difference between (a) and (b). The horizontal axis shows the
position of the DNA front in the pore
7.4.2 Translocation of a One Mutated Base Single-Stranded
DNA in a Stretch Conformation
The modeled capacitor membrane consists of a 2 nm thick SiO 2 layer sandwiched
between two heavily doped n + - Si layers of 4.5 nm thickness each. The nanopore in
the capacitor membrane has a double-conical shape with the diameter of the
narrowest part of 1 nm (see details in [ 19 , 31 ]). Taking the distribution of the
DNA's charge from atomistic simulations, we solve self-consistently the Poisson
equation, assuming the ions in the electrolyte obey the Boltzmann distribution,
whereas electrons and holes in the semiconductor are ruled by the Fermi-Dirac
statistics. This model was described elsewhere in details [ 19 , 31 ]. The average ion
concentrations that we obtain in the pore correlate with the data obtained by
molecular dynamics simulations. Since we are interested in the average induced
signal on the electrodes we believe that our solution model accurately describes the