Encapsulation of L-Histidine Amino Acid Inside Single-Walled Carbon Nanotubes

Carbon nanotubes have attracted considerable interest for their use as carriers of drugs across biological barriers. In this work, we investigate the encapsulation of L-Histidine amino acid inside a single-walled carbon nanotube, and determine the resultant interaction energy for various sizes of the nanotubes. In our model, the L-Histidine amino acid is accounted for in four parts; the inner ring group, the half outer group, the linear part and the cylinder group, all interacting with a single-walled carbon nanotube. We calculate the acceptance and suction energies which depend on the radius r of the carbon nanotube and the orientation angle circle divide that the amino acid makes with the central axis of the nanotube. Our results indicate the acceptance of the L-Histidine amino acid into carbon nanotubes of r > 3.7 angstrom, which is in good agreement with other recent studies.