Quantum Molecular Descriptors of 6-Thioguanine Adsorbed PPy-PNVK Conducting Polymer: A DFT Analysis

Abstract

6-Thioguanine (6-TG) is an important drug to cure cancer with fierce adverse effects on human being, necessitating its frequent monitoring. Present work reports the computational analysis of a copolymer (PPy-PNVK), synthesized using polypyrrole (PPy) and poly(9-vinyl carbazole) (PNVK) host polymers. The sensing ability of these polymers for 6-TG, has been performed through the DFT formulated ab initio approach employing the generalized gradient approximations (GGA), considering the revised-Perdew, Burke and Ernzerh (rPBE) pattern of parameters. The suitability of these polymers for 6-TG sensing application, has been assessed by analyzing the variations in the HOMO-LUMO gaps, density of state (DOS), Mulliken population, molecular energy spectrum (MES), adsorption energy (Eads), bond variation, chemical reactivity of the surface, the recovery time (τ) and the electron density plots. The estimated negative adsorption energy confirms the physisorption and stability of 6-TG on PPy, PNVK and their copolymer counterpart. Considering the recovery time, range of detection, reusability and quantum molecular descriptors as an important sensing parameters, it has been observed that the computationally synthesized copolymer is relatively better in comparison to its host polymers.