Offset configurations for single and double strand DNA inside single-walled carbon nanotubes

Journal Article
مستخلص المنشور: 

Nanotechnology is a rapidly expanding research area, and it is believed that the
unique properties of molecules at the nano-scale will prove to be of substantial ben
efit to mankind especially so in medicine and electronics. Here we use applied mathe
matical modelling exploiting the basic principles of mechanics and the 6-12 Lennard
Jones potential function together with the continuum approximation, which assumes
that intermolecular interactions can be approximated by average atomic surface
densities. We consider the equilibrium offset positions for both single-strand and
double-strand DNA molecules inside a single-walled carbon nanotube, and we pre
dict offset positions with reference to the cross-section of the carbon nanotube. For
the double-strand DNA, the potential energy is determined for the general case for
any helical phase angle φ, but we also consider a special case when φ = π, which

leads to a substantial simplification in the analytical expression for the energy. As
might be expected, our results confirm that the global minimum energy positions
for a single-strand DNA molecule and a double-strand DNA molecule will lie off axis
and they become closer to the tube wall as the radius of the tube increases.