Computational Studies of Nucleotide Selectivity in DNA–Carbon Nanotube Hybrids

Using classical molecular mechanical techniques, we have investigated the morphological properties and interaction mechanisms of single-walled carbon nanotubes (SWNT) functionalized by DNA. Our simulations evidence sequence preference trends for the homogeneous single-strand DNA on the (6,5) vs the (9,1) SWNTs. The DNA–SWNT interaction strength is ordered as G ≳ A > C > T for (9,1) and A > C > G > T for (6,5) hybrids. This preference in a DNA sequence versus tube chiralities is accompanied by variations in wrapping geometries, demonstrating large wrapping angles (40–60°) for the (6,5) and two ranges of wrapping angles (10–30° and 45–60°) for the (9,1) systems. In addition, we found correlations between the most stable wrapping angles of SWNT–DNA hybrids and the most preferential DNA orientations on the graphene with respect to its lattice vectors, which could elucidate the sensitivity of SWNT–DNA structures to the DNA sequence