Solid State Nanopores for Selective Sensing of DNA - Nanopores: Sensing and Fundamental Biological Interactions - page 117

a b

Voltage Applied vs. vdW Force Voltage Applied vs. Velocity of DNA

30

1.2

1

25

0.8

20

0.6

15

0.4

10

0.2

5

0

-0.2 0

0 10 20 30 40 50 0 10 20 30 40 50

Voltage Applied (Volts) Voltage Applied (Volts)

c

Voltage Applied vs. Ionic Current

300

250

200

150

100

50

0

0 10 20 30 40 50

Voltage Applied (Volts)

Fig. 5.6 Figure shows the effect of applied voltage on (a) van der Waals force (b) translocation
velocity and (c) ionic current. Van der Waals force and ionic current display parabolic behavior,
and translocation velocity shows nearly linear dependence on the applied voltage. Reprinted by
permission from New World Publishing International: American Journal of Biomedical Sciences,
copyright (2009)

Fig. 5.7 . The reorientation of the tethered DNA plays very important role in estima-
ting the effective diameter under varying applied potential. In Fig. 5.7b , it can
be seen that applied potential plays a very vital role in estimating the pore diameter.
Pore diameter increases almost linearly with the increasing applied potential.
The effect of potential is more considerable when in the sub-nanometer range.
In the case of polymer coating, a new model will be required to estimate the pore
diameter at a certain voltage. The model of ref [ 27 ] is limited due to having a
translocation time of less than 100 ns. For translocation times in milliseconds,
they suggested a new model for low-voltage DNA kinetics.