Effect of chirality and curvature of single-walled carbon nanotubes on the adsorption of uracil

Adsorption of uracil on single-walled carbon nanotubes (SWCNTs) (5,2) and (5,5) in the presence of water molecules has been investigated using first-principles technique. Uracil is adsorbed on the nanotube noncovalently through π-π stacking interaction. The binding strength of uracil varies with the chirality of the carbon nanotubes. Addition of water molecules inside and outside the nanotube altered the interaction of the uracil with the nanotube and modifies the binding strength. Orientation of the water molecule and the charge transfer through the C-H bonds are the important factors in the interaction of the water molecule with the carbon nanotube.