Analysis of structural, and electronic properties of clopidogrel drug adsorption on armchair (5, 5) Single-walled carbon nanotube

Single-walled carbon nanotubes (SWCNTs) have been widely utilized in many types of applications, cinfirming their excellent role as carriers of drugs with a highly site-selective delivery capability. As nanotubes can release drugs into the tissue cells without damaging the healthy cells, it is necessary to determine the structural properties of drugs–SWCNTs complexes which may lead to the development of optimal SWCNTs as new effective drug transporters. In this work, a theoretical study of structural properties and reactivity of clopidogrel drug with C (5, 5) carbon nanotubes is presented. Computational and chemical simulations were carried out for clopidogrel, SWCNT and clopidogrel-SWCNT by B3LYP/6-31+G with the Gaussian 09 program and then energies of all optimized configurations were evaluated by the M06-2X density functional method. The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), natural bond orbital (NBO), global reactivity descriptors and density of states (DOS) of clopidogrel and SWCNT were calculated. The results show that there is a relationship between the energy gap and the DOS. The nature of interaction and bonding between the clopidogrel and SWCNT is physisorption as the adsorption energy and charge transfer is small, and adsorption distance is large. Generally, the results of our simulation studies demonstrated that, the carbon nanotubes have a high potential to be considered as carriers of clopidogrel in drug delivery systems. Band gaps of clopidogrel-SWCNT complex, which were computed by B3LYP method, are 1.777 and 1.860 eV in gas and the solution phases, respectively. Also, the dipole moment of clopidogrel-SWCNT complex in solution phase is 5.286 Debye, which is higher than the gas phase (3.234 Debye). These results show the effect of the solvent on the complex.