Putrescine adsorption on pristine and Cu-decorated B12N12 nanocages: A density functional theory study

In silico investigation on sensing of tyramine by boron and silicon doped C60 fullerenes

The present communication deals with the adsorption of tyramine neurotransmitter over the surface of pristine, Boron (B) and Silicon (Si) doped fullerenes. Density functional theory (DFT) calculations have been used to investigate tyramine adsorption on the surface of fullerenes in terms of stability, shape, work function, electronic characteristics, and density of state spectra. The most favourable adsorption configurations for tyramine have been computed to have adsorption energies of - 1.486, - 30.889, and - 31.166 kcal/mol, respectively whereas for the rest three configurations, it has been computed to be - 0.991, - 6.999, and - 8.796 kcal/mol, respectively. The band gaps for all six configurations are computed to be 2.68, 2.67, 2.06, 2.17, 2.07, and 2.14 eV, respectively. The band gap of pristine, B and Si doped fullerenes shows changes in their band gaps after adsorption of tyramine neurotransmitters. However, the change in band gaps reveals more in B doped fullerene rather than pristine and Si doped fullerenes. The change in band gaps of B and Si doped fullerenes leads a change in the electrical conductivity which helps to detect tyramine. Furthermore, natural bond orbital (NBO) computations demonstrated a net charge transfer of 0.006, 0.394, and 0.257e from tynamine to pristine, B and Si doped fullerenes.

Density Functional Theory Study of Cu-Modified B12N12 Nanocage as a Chemical Sensor for Carbon Monoxide Gas

The development of efficient B₁₂N₁₂-based toxic gas sensors has received considerable attention from the scientific community. Thus, in this regard, quantum chemical calculations were performed using density functional theory (DFT) at the B97D/6-31G(d,p) level for all of the studied systems. Modification of copper on B₁₂N₁₂ results in five optimized structures, named CuB₁₁N₁₂ and B₁₂N₁₁Cu (doped structures), Cu@b₆₆ and Cu@b₆₄ (decorated structures), and Cu@B₁₂N₁₂ (encapsulated structure). The results indicate that the CO gas weakly physisorbed on the B₁₂N₁₂ nanocage. It was found that the gas adsorption performance of B₁₂N₁₂ is improved due to the introduction of the Cu atom, but the interaction between CO and B₁₂N₁₁Cu, Cu@B₁₂N₁₂, Cu@b₆₄, and Cu@b₆₆ nanocages is strong, limiting the applications as a sensor. Particularly, the CuB₁₁N₁₂ system shows moderate adsorption (E_ads = -0.6 eV) and a high electronic sensitivity (ΔE_gap = 81.6%) toward CO gas, compared to other modified systems. Furthermore, based on the sensor performance analysis, it was found that CuB₁₁N₁₂ presented low recovery time (14 ms) and high selectivity for CO detection, making it a promising fast response sensor. Finally, our results demonstrated the capability of CuB₁₁N₁₂ as a superior sensor material for applications involving the selective detection of CO gas.