Investigation of antimicrobial potential of nanocomposites based on functionalization of graphene oxide with zinc porphyrin complexes

Abstract

Herein, zinc porphyrin complexes were synthesised by passing through the formation of free base porphyrin ligands and metalation of free base porphyrins with zinc metal ions. The synthesised zinc porphyrin complexes were functionalised with graphene oxide leading to the formation of zinc porphyrin anchored graphene oxide hybrid nanocomposites. The zinc porphyrins complexes were anchored with graphene oxide through the particular functional group present at the periphery of zinc porphyrins (hydroxyl and carboxyl functional groups in Pr1 and Pr2 respectively). 1H NMR and UV–visible spectroscopic techniques have monitored the successful formation of free base porphyrins and their matching zinc-integrated metalloporphyrin complexes. Various spectroscopic techniques like, photophysical properties (UV–Visible spectroscopy and Fluorescence spectroscopy), Fourier transform infrared (FT-IR), powdered X-ray diffraction (P-XRD) patterns, FE-SEM and EDAX analysis were used to examine the intrinsic characteristics of the prepared nanocomposites. The in-vitro antimicrobial activity of the synthesized complexes and nanocomposites was tested against Staphylococcus aureus gram-positive strain, Klebsiella pneumonia, and Escherichia coli. By working on the antimicrobial behaviour, it has been observed that the compound containing –COOH substitute has shown enhanced antimicrobial activity. The in silico molecular docking studies of the synthesized compounds with the S. aureus nucleoside diphosphate kinase receptor showed strong interactions via hydrogen bonding, π − π interactions and hydrophobic interactions. Molecular dynamics (MDs) simulations were used to study the dynamic behaviour of the complexes as well as nanocomposites which revealed the stability of docked structures with S. aureus nucleoside diphosphate kinase receptor. The in-silico pharmacokinetics studies showed the drug-likeness, non-toxic nature and safe oral administration of the synthesized compounds.