Fig. 6 (f) Bandstructure and DOS plot – complex Z2.
The availability of a greater number of states enunciates the happening of bio-molecule interaction on Kagome-PNT. As the alteration in the electronic features for the bio-molecules interacted complexes are studied, COHP analysis is implemented and presented in Fig. 7 (a) – (c). A drastic variation can be reckoned for each bio-molecule interaction at specific site. In case of Complex X1 and X2, since the interaction of asparagine is made through the oxygen (O) atom on Kagome-PNT, COHP is calculated for P-O bond. Moreover, the VFA – lactate and polyamine – putrescine are admitted to interact with Kagome-PNT through O and N atom respectively, so COHP calculations for Complex Y and Z are performed on P-O and P-N bonds correspondingly. For complex X1, though the bonding bestowment is observed near -8.3 eV (valence band) and 6.4 eV (conduction band) in the form of spikes, maximum bestowment comes from antibonding, especially near the Fermi energy level (EF). However, for complex X2, a greater absolute value of COHP (-3.3) is noticed near 14 eV (conduction band) contributing to bonding attribute and the antibonding bestowment is observed to be trivial. For complex Y1, an equal number of bonding (negative COHP measure) and antibonding (positive COHP measure) is reckoned. Yet, the antibonding characteristic is found to be dominant for complex Y2 with a fewer spike indicating bonding nature at higher energy levels (8 to 12 eV). In case of complex Z1 and Z2, bonding features are found predominant at higher energy levels (7 to 12 eV – conduction band) along with the prevalence of antibonding characteristics throughout the valence band and at lower energy levels of conduction band. Although the variation in the distribution of bonding and antibonding attributes for the complexes X, Y and Z are figured out through the COHP plot, the non-bonding characteristic at the Fermi energy level (EF) remains the same for all the bio-molecule interacted complexes. The electronic features elaborated so far ensures our preference of Kagome-PNT to sense the molecules – asparagine, lactate and putrescine.