Capture and Translocation of Nucleic Acids into Sub-5 nm Solid-State Nanopores - Nanopores: Sensing and Fundamental Biological Interactions - page 237

Fig. 10.6 Log-log plots of
the capture rates of a 400 bp
fragment into a 4 nm pore as a
function of DNA
concentration, under
symmetric and asymmetric
salt conditions (slopes of lines
~1). Reproduced with
permission from Wanunu
et al. [ 50 ], Copyright Nature
Publishing Group

Fig. 10.7 The dependence of
the specific capture rate of
dsDNA into 4 nm solid-state
nanopores, as a function of
DNA length. A transition
from length-dependent to
length-independent regimes is
observed at ~8,000 bp.
Reproduced with permission
from Wanunu et al. [ 50 ],
Copyright Nature Publishing
Group

process is dominated by a free energy barrier, described by ( 10.4 ). This is indeed
confirmed by an excellent fit to the data (shown by the solid line). Similarly, in the
range 8,000-48,000 bp, we observe length-independent behavior, indicating that
this regime is diffusion-dominated, as described by ( 10.3 ) (dashed line).
The voltage dependence of the capture rate was also studied in these two
regimes. Figure 10.8 displays the results for three DNA lengths: 400, 3,500 and
48,000 bp (I-III respectively). For molecules shorter than ~8,000 bp we observe an
exponential dependence of R c 450 mV [ 50 ]. These results

support the hypothesis that in this length regime, the capture process is dominated
by the threading energy barrier process, described by ( 10.4 ). In contrast, for both

on V for voltages <