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.