Understanding the Interaction of Nucleobases with Chiral Semiconducting Single-Walled Carbon Nanotubes: An Alternative Theoretical Approach Based on Density Functional Reactivity Theory

The present study describes an alternative and computationally cost-effective theoretical approach to explore the interaction of nucleobases with different semiconducting chiral single-walled carbon nanotubes (SWCNTs). Implementing density functional reactivity theory (DFRT) based CDASE (comprehensive decomposition analysis of stabilization energy, Bagaria et al. Phys. Chem. Chem. Phys. 2009, 11, 8306), scheme kinetic and thermodynamic aspects of the interaction between different DNA bases as well as Watson-Crick base pairs (AT and GC) with SWCNTs are investigated and that is also without performing computationally intensive transition state optimization or thermochemistry calculation. The trend of interaction generated by reactivity parameters (based on the CDASE scheme) follows the experimentally as well as theoretically verified order, G > A > T > C > U, observed earlier. Conventional binding energy calculations on some of the chosen systems using the ONIOM QM:MM approach generate a reasonably satisfactory trend of interaction. Reported theoretical findings can be exploited as an alternative (albeit qualitative but rapid) technique to understand the functionalization of CNTs with DNA bases.