title: The in Silico Insight into Carbon Nanotube and Nucleic Acid Bases Interaction.
abstract: BACKGROUND
  To explore practical applications of carbon nanotubes (CNTs) in biomedical fields the properties of their interaction with biomolecules must be revealed. Recent years, the interaction of CNTs with biomolecules is a subject of research interest for practical applications so that previous research explored that CNTs have complementary structure properties with single strand DNA (ssDNA).
  
  
  OBJECTIVE
  Hence, the quantum mechanics (QM) method based on ab initio was used for this purpose. Therefore values of binding energy, charge distribution, electronic energy and other physical properties of interaction were studied for interaction of nucleic acid bases and SCNT.
  
  
  METHODS
  In this study, the interaction between nucleic acid bases and a (4, 4) single-walled carbon nanotube (SCNT) were investigated through calculations within quantum mechanics (QM) method at theoretical level of Hartree-Fock (HF) method using 6-31G basis set. Hence, the physical properties such as electronic energy, total dipole moment, charge distributions and binding energy of nucleic acid bases interaction with SCNT were investigated based on HF method.
  
  
  RESULTS
  It has been found that the guanine base adsorption is bound stronger to the outer surface of nanotube in comparison to the other bases, consistent with the recent theoretical studies. In the other words, the results explored that guanine interaction with SCNT has optimum level of electronic energy so that their interaction is stable. Also, the calculations illustrated that SCNT interact to nucleic acid bases by noncovalent interaction because of charge distribution an electrostatic area is created in place of interaction.
  
  
  CONCLUSIONS
  Consequently, small diameter SCNT interaction with nucleic acid bases is noncovalent. Also, the results revealed that small diameter SCNT interaction especially SCNT (4, 4) with nucleic acid bases can be useful in practical application area of biomedical fields such detection and drug delivery.
authors.affiliation: Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Ali Asghar
authors.initials: AA
authors.lastname: Karimi
authors.affiliation: Department of Medical Nanotechnology, Science and Research Branch, Islamic Azad Univerity, Tehran, IR Iran.
authors.forename: Behafarid
authors.initials: B
authors.lastname: Ghalandari
authors.affiliation: Department of ENT-Head and Neck Surgery, ENT-Head and Neck Surgery Research Center, Rasool Akram Hospital, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Seyed Saleh
authors.initials: SS
authors.lastname: Tabatabaie
authors.affiliation: Department of ENT-Head and Neck Surgery, ENT-Head and Neck Surgery Research Center, Rasool Akram Hospital, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Farhadi
keywords: Binding Energy; Carbon Nanotube; Interaction; Nucleic Acid Base