Electronic, Nonlinear Optical, Reactivity and Solubility Analysis of the Antimalarial Drug Dihydroartemisinin Functionalized on Carbon Nanotube: DFT Study

The purpose of the current study is to enhance the targeted distribution of the dihydroartemisinin (DHA) medication and model novel nanometric compounds for use in nanotechnologies by functionalizing DHA on the (5,5) single wall carbon nanotube (SWCNT, C60H20) utilizing the 1,3-diploar cycloaddition (DC) reaction of azomethine ylide. To examine the use of functionalized carbon nanotubes (fCNTs) as a nanovector for the intended delivery of the antimalarial drug dihydroartemisinin, density functional theory (DFT) calculations of the drug were performed in gas phase and in solution. According to the geometric optimization's findings, DHA's molecular structure is unaffected by functionalization. Based on the findings of binding and solvation energies, two energetically stable configurations were identified in 1st (fCNT1-2) and 2nd (2fCNT1-2) functionalization. For these stable configurations, the energy gap value goes from 1.52 eV for the (5,5) single wall pristine CNT to 1.27 eV for the 1st functionalization and to 1.06 eV for the 2nd functionalization regardless of the considered media; which gives these nanostructures excellent semiconductor properties. Global reactivity descriptor results reveal that the functionalized CNT has significantly enhanced reactivity in solvent conditions and that the functionalization of DHA has decreased stability while increasing reactivity. Thus, the fundamental gap (Ef) in gas phase decreases from 3.65 eV for the virgin CNT to 3.30 eV for fCNT2 and to 3.02 eV for 2fCNT2. On the contrary, in water Ef goes from 1.20 eV for the virgin CNT to 0.95 eV for fCNT2 and to 0.74 eV for 2fCNT2; demonstrating an improvement in the reactivity of the investigated fCNTs as nanovectors for targeted delivery of DHA drug. Finally, the results of this study indicate that these nanostructures could also have favorable NLO characteristics, making them potentially useful materials for NLO applications.