Sonochemical synthesis of bioinspired graphene oxide-zinc oxide hydrogel for antibacterial painting on biodegradable polylactide film

Nanotechnology. 2024 May 7;35(30). doi: 10.1088/1361-6528/ad40b8.

Abstract

Graphene oxide nanosheet (GO) is a multifunctional platform for binding with nanoparticles and stacking with two dimensional substrates. In this study, GO nanosheets were sonochemically decorated with zinc oxide nanoparticles (ZnO) and self-assembled into a hydrogel of GO-ZnO nanocomposite. The GO-ZnO hydrogel structure is a bioinspired approach for preserving graphene-based nanosheets from van der Waals stacking. X-ray diffraction analysis (XRD) showed that the sonochemical synthesis led to the formation of ZnO crystals on GO platforms. High water content (97.2%) of GO-ZnO hydrogel provided good property of ultrasonic dispersibility in water. Ultraviolet-visible spectroscopic analysis (UV-vis) revealed that optical band gap energy of ZnO nanoparticles (∼3.2 eV) GO-ZnO nanosheets (∼2.83 eV). Agar well diffusion tests presented effective antibacterial activities of GO-ZnO hydrogel against gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). Especially, GO-ZnO hydrogel was directly used for brush painting on biodegradable polylactide (PLA) thin films. Graphene-based nanosheets with large surface area are key to van der Waals stacking and adhesion of GO-ZnO coating to the PLA substrate. The GO-ZnO/PLA films were characterized using photography, light transmittance spectroscopy, coating stability, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopic mapping (EDS), antibacterial test and mechanical tensile measurement. Specifically, GO-ZnO coating on PLA substrate exhibited stability in aqueous food simulants for packaging application. GO-ZnO coating inhibited the infectious growth ofE. colibiofilm. GO-ZnO/PLA films had strong tensile strength and elastic modulus. As a result, the investigation of antibacterial GO-ZnO hydrogel and GO-ZnO coating on PLA film is fundamental for sustainable development of packaging and biomedical applications.

Keywords: antibacterial and biodegradable film; antibacterial coating; graphene hydrogel; graphene oxide–zinc oxide; hydration swelling.

MeSH terms

  • Anti-Bacterial Agents* / chemical synthesis
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Escherichia coli* / drug effects
  • Graphite* / chemistry
  • Graphite* / pharmacology
  • Hydrogels* / chemical synthesis
  • Hydrogels* / chemistry
  • Hydrogels* / pharmacology
  • Microbial Sensitivity Tests
  • Nanocomposites / chemistry
  • Polyesters* / chemistry
  • Polyesters* / pharmacology
  • Staphylococcus aureus* / drug effects
  • Ultrasonic Waves
  • Zinc Oxide* / chemistry
  • Zinc Oxide* / pharmacology

Substances

  • Zinc Oxide
  • Graphite
  • Anti-Bacterial Agents
  • graphene oxide
  • poly(lactide)
  • Polyesters
  • Hydrogels