2. Estimation details
The density functional theory mode is adopted to carry out the investigation on the potentiality of the 2DNM – Kagome-form of Phosphorene nanotube (Kagome-PNT) to be used as a fundamental component in chemi-resistive based sensor to detect the malicious aura producing bio-molecules – asparagine (amino acid), lactate (VFA) and putrescine (polyamine). The software package facilitating the scrutinization on Kagome-PNT is SIESTA [39]. The perfect conformation of the fundamental component is accomplished by converging the atomic forces on the constituent phosphorus atoms to 0.001 eV/Å and the energy convergence is adjusted to 10-6 eV. For the geometrical optimization, Grimme’s DFT-D2 correction is used while choosing significance of van der Waals interaction [40]. The kinetic-energy cut-off is set to 500 eV. The exploration on the conformational and electronic features of the pure Kagome-PNT and bio-molecules interacted Kagome-PNT is implemented under the framework of GGA-B3LYP exchange-correlation functional. The conformational stability of Kagome-PNT is verified using the formation energy. Besides, bonding and antibonding aspects between Kagome-PNT and target molecules are studied with regard to Crystal Orbital Hamiltonian Population (COHP) analysis [41]. The factors Density of states (DOS) spectrum and Band Structure under electronic features are explored for the pure and bio-molecules interacted Kagome-PNT after the sampling of Brillouin zones at 1 x 1 x 25 are finalized. Moreover, double zeta polarization basis set and a vacuum padding of 16 Å are fulfilled following which the interaction features namely the binding energy, average energy gap alteration and Bader charge transfer are gauged.