DNA adsorption on graphene
Nanomechanics Group, School of Mathematical Sciences,
University of Adelaide, Adelaide, SA
Received in final form: 17 July 2013
Published online: 1 November 2013
Here we use classical applied mathematical modeling to determine surface binding energies between both single-strand and double-strand DNA molecules interacting with a graphene sheet. We adopt basic mechanical principles to exploit the 6–12 Lennard-Jones potential function and the continuum approximation, which assumes that intermolecular interactions can be approximated by average atomic line or surface densities. The minimum binding energy occurs when the single-strand DNA molecule is centred 20.2 Å from the surface of the graphene and the double-strand DNA molecule is centred 20.3 Å from the surface, noting that these close values apply for the case when the axis of the helix is perpendicular to the surface of graphene. For the case when the axis of the helix is parallel to the surface, the minimum binding energy occurs when the axis of the single-strand molecule is 8.3 Å from the surface, and the double-strand molecule has axis 13.3 Å from the surface. For arbitrary tilted axis, we determine the optimal angles Ω of the axis of the helix, which give the minimum values of the binding energies, and we observe that the optimal angles tend to occur in the intervals Ω ∈ (π / 4,π / 2) and Ω ∈ (π / 7,π / 5) for the single and double-strand DNA molecules, respectively.
Key words: Molecular Physics and Chemical Physics
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2013