Carbon nanotubes (CNTs) have been attracting attention because they have characteristic mechanical and electronic properties. We investigate the deformation behavior of a tyramine molecule on surface of H-capped (5,0) single-walled carbon nanotubes (SWCNT) with different lengths are studied by density functional theory (DFT) calculations. Binding energies clearly represent, adsorption depended on tube length. Also adsorption of tyramine (C8H11NO) on (5, 0) carbon nanotube was performed at the B3LYP and B3PW91level of DFT. The tubetyramine interactions were discussed in the terms of binding energy (EB), Charge density, molecules orbitals, dipole moments and the natural bond orbital (NBO). The results reveal that additions of water molecules to tubetyramine system increase the interaction between tube and tyramine molecule.
