Determination of the optimal nanotube radius for single-strand DNA encapsulation

مقال فى مجلة

We model the molecular interactions between a single-strand DNA molecule and
a carbon nanotube to determine the suction force experienced by the DNA which
is assumed to be located on the axis near the open end of a single-walled carbon
nanotube. We determine the optimal nanotube radius for encapsulation, that is the
radius of nanotube with the lowest interaction energy. The expression for the molec
ular interaction energy is derived from the 6-12 Lennard-Jones potential together
with the continuum approach, which assumes that a discrete atomic structure can
be replaced by a line or surface with constant average atomic density. We find that
a single-strand DNA can be encapsulated inside a single-walled carbon nanotube with a radius larger than 8.2 ˚A, and we show that the optimal single-walled carbon nanotube needed to fully enclose the DNA molecule has radius 8.8 ˚A, which ap
proximately corresponds to the chiral vector numbers (13, 13). This means that if
we wish to encapsulate single-strand DNA into a carbon nanotube, an ideal single
walled carbon nanotube to do this is (13, 13) which has the required radius of 8.8 ˚ A.