Figure 4.

Variation of the binding energy of the CNT-DNA hybrids with the DNA wrapping angle. The solid lines correspond to hybrid configurations with fixed ends, that is, where the end bases of the DNA molecule are fixed and all other atoms of the hybrid system are free to move during geometry optimization. Dashed lines represent the optimized hybrid structure where all the atoms are allowed to move during optimization. The red line corresponds to the hybrid constructed out of 3 unit-long (6,5) tube (3u) and DNA strand consisting of 25 guanine bases (G-25); the black line represents the same tube but with 25-mer cythosine bases (C-25); the dark green line represents (6,5) tube of 4 repeat units in length (4u) with adsorbed 23-mer cythosine bases (C-23). The light green dashed line corresponds to configurations constructed from the (6,5) nanotube of 4 repeat units in length (4u) and 29-mer cythosine bases (C-29).