Weak intermolecular interactions of cysteine on BNNT, BNAlNT and BC2NNT: a DFT investigation

The study of intermolecular interactions is of great importance. This study attempted to quantitatively examine the interactions between cysteine (C3H7NO2S) amino acid molecule with pristine boron nitride, Al-doped boron nitride and carbon boron nitride nanotubes (BNNT, BNAlNT, BC2NNT, respectively) in vacuum. Quantum mechanical studies of such systems are possible in the density functional theory (DFT) framework. For this purpose, various functionals, such as B3LYP-D3, omega B97XD and M062X, have been used. One of the most suitable basis functionals for the systems studied in this research is 6-311G(d), which has been used in both optimization calculations and calculations related to wavefunction analyses. The main part of this work is the study of various analyses that reveal the nature of the intermolecular interactions between the two components introduced above. The results of conceptual DFT, natural bond orbital, non-covalent interactions and quantum theory of atoms in molecules were consistent and in favour of physical adsorption in all systems. Al-doped nanotube provides more adsorption energy than others. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy gaps were as follows: BNNT: 6.545, BNAlNT: 8.127 and BC2NNT: 7.027 eV at B3LYP-D3/6-311G(d) model chemistry. The sensitivity of the adsorption increased when an amino acid molecule interacted with doped BNNT, and could be used to design a nanocarrier for cysteine amino acid.

Automated summary

This study investigates the interactions between cysteine amino acid and different nanotubes using density functional theory. The results show that the Al-doped nanotube has the highest adsorption energy, making it a potential nanocarrier for cysteine amino acid.