Investigation of Solvent Effects on Interaction of Single-Strand DNA with Open-End of Single Walled Carbon Nanotubes Using QM and MM methods

The interaction of biomolecules with carbon nanotubes (CNTs) has generated a great deal ofinterest in the past few years. The interaction between B-form single-strand DNA (ssDNA) andsingle-walled carbon nanotubes (SWCNTs) is a subject of intense current interest; however thereare a relatively small number of papers in the literature dealing with interaction of DNA andSWCNTs. In this work we investigate interaction of ssDNA with open-end of SWCNT; usingAMBER, MM+ and OPLS force fields in molecular mechanic (MM) method. We study effects ofincrease the molecular number of solvent on interaction of ssDNA with SWCNTs, using theseforce fields too. The interaction of ssDNA with open-end of SWCNT in water and ethanol havebeen calculated using density functional theory (DFT) at the theoretical level of B3LYP/6-31G (d,p) and have been made a comparison between dipole moment; energy and atomic charges invacuum; water and ethanol. Our results show that interaction of ssDNA with open-end of SWCNTcould be optimum in polar solvent.