Density functional theory study to functionalization of BC₂N nanotubes with cysteine amino acid

The density functional theory (DFT) was used to study the interaction of cysteine amino acid with (8, 0) zigzag single-walled BC₂N nanotubes (BC₂NNTs) both in gas and solvent phases. The interaction between cysteine amino acid and BC₂NNTs is found to be energetically favorable in both phases. Based on the calculations of solvation energy, it can be seen that the dissolution of BC₂NNT/amino acid complex in water is spontaneous. During the functionalization process, the quantum molecular descriptor and the energy of adsorption changed significantly. Findings suggest that the cysteine amino acid can be considerably adsorbed chemically onto the surface of BC₂NNTs. Based on the E_g values obtained, the cysteine molecule caused a reduction in the E_g value, which also increased the reactivity and conductivity of functionalized BC₂NNTs. According to the findings of chemical hardness, the kinetic stability of the functionalized nanotubes was better than pure nanotubes. As a result of this approach, E_g values are indicative of high propensity reaction and electron transfer. Our findings have shown that BC₂NNTs can function as an appropriate drug delivery system for cysteine amino acid within biological systems for the adsorption of the drug and controlled drug release.