  In this short note, a correction is made to the recently proposed solution
[1] to a 1D biased diffusion model for linear DNA translocation and a new
analysis will be given to the data in [1]. It was pointed out [2] by us
recently that this 1D linear translocation model is equivalent to the one that
was considered by Schrodinger [3] for the Enrenhaft-Millikan measurements [4,5]
on electron charge. Here we apply Schrodinger's first-passage-time distribution
formula to the data set in [1]. It is found that Schrodinger's formula can be
used to describe the time distribution of DNA translocation in solid-state
nanopores. These fittings yield two useful parameters: drift velocity of DNA
translocation and diffusion constant of DNA inside the nanopore. The results
suggest two regimes of DNA translocation: (I) at low voltages, there are clear
deviations from Smoluchowski's linear law of electrophoresis [6] which we
attribute to the entropic barrier effects; (II) at high voltages, the
translocation velocity is a linear function of the applied electric field. In
regime II, the apparent diffusion constant exhibits a quadratic dependence on
applied electric field, suggesting a mechanism of Taylor dispersion effect
likely due the electro-osmotic flow field in the nanopore channel. This
analysis yields a dispersion-free diffusion constant value for the segment of
DNA inside the nanopore which is in agreement with Stokes-Einstein theory
quantitatively. The implication of Schrodinger's formula for DNA sequencing is
discussed.
