Biogenic PLGA-Zinc oxide nanocomposite as versatile tool for enhanced photocatalytic and antibacterial activity

Abstract

Metal oxide (ZnO-NPs) and hybrid polymeric poly (dl-Lactide-co-glycolide)-metal oxide nanocomposites (PLGA–ZnO-NC) were fabricated via biogenic and modified solvent emulsification–diffusion method, respectively. The optical, morphological, elemental traits, along with photocatalytic and bactericidal activity of the nanosystems were intrigued using state of art analytical techniques viz. UV–Vis, ATR-FTIR, XRD, DLS, FE-SEM, and EDS. The fabricated nanostructured system possessed exceptional morphological, optical and physicochemical traits. PLGA–ZnO-NC depicted a significantly enhanced photocatalytic degradation of anthropogenic mutagenic dye viz. malachite in comparison to the pristine ZnO-NPs. The kinetics of degradation has been deciphered using Langmuir–Hinshelwood equation. The degradation kinetic followed a pseudo first-order model and the rate constants were found to be 1.4 × 10−2 s−1 and 5.7 × 10−3 s−1 for ZnO-NPs and PLGA–ZnO-NC, respectively. The antibacterial activity of the nanocomposite has been evaluated against Gram (+) ve (S. aureus) and Gram (−) ve (E. coli) bacterial strain. Disc diffusion assay depicted enhanced antibacterial activity of PLGA–ZnO-NC (~ 1.5 times) in comparison to the ZnO-NPs, respectively. FE-SEM analysis displayed disrupted cell membrane integrity corroborating the disc diffusion assay.