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<p>Bacterial and fungal infections remain a major global health challenge, exacerbated by the rise of antimicrobial resistance and the limited efficacy of conventional treatments. Although metal oxide nanoparticles of Zinc oxide and silver have the power to kill germs, but they don’t work as well since they don’t stay stable in colloidal form and clump together quickly, making it harder to control how nanoparticles spread. Because current preparation methods are hard to use, a clean, eco-friendly method is needed to get nanoparticles to be very stable and evenly spread out while also making them more effective against germ. Silver (Ag) and zinc oxide (ZnO) nanoparticles were prepared by pulsed laser ablation in liquid (PLAL) and subsequently integrated with graphene oxide (GO) by ultrasonication to yield ternary GO: Ag: ZnO nanocomposites at three weight ratios (5:2.5:2.5; 5:3:2; 5:4:1). Structural and surface analyses (XRD, FE-SEM/EDS, HR-TEM, FT-IR,. Raman Spectroscopy, UV–Vis, zeta potential) confirmed polycrystalline Ag (cubic) and ZnO (wurtzite) distributed on crumpled GO sheets with ~ 30–50&#xa0;nm particle sizes(the standard deviation was found to be ± 10.6&#xa0;nm, (Ag) and standard variation of ± 10.2&#xa0;nm. (ZnO). TEM analysis confirmed that silver and zinc oxide particles were spherical, while that GO was in compact, overlapping sheets .FTIR and Raman results confirme the successful formation of GO–Ag–ZnO of the D and G bands. Zeta potentials (Ag ≈ − 32.04 mV, ZnO ≈ + 8.01 mV, GO ≈ − 43.25 mV) indicated stable Ag and GO colloids and comparatively lower stability for ZnO. Antimicrobial performance was assessed by agar well-diffusion against <i>S. aureus</i> and <i>Candida albicans</i>, and by minimum inhibitory concentration (MIC) against (<i>S. aureus)</i>, <i>Streptococcus spp</i>., <i>E.coli</i>, <i>Klebsiella pneumoniae</i>, and <i>(p.aeruginosa)</i>. In diffusion tests, all composites produced12 ± 0.47&#xa0;mm zones for <i>Staphylococcus aureus (S. aureus)</i> at 0.2/0.3&#xa0;µg mL⁻¹ and 14 ± 0.47&#xa0;mm for <i>C. albicans</i>; the single-component Ag, ZnO, and GO were also active at these doses. In MIC assays, Sample A (5:2.5:2.5) inhibited <i>Streptococcus spp</i>. And <i>E. coli</i> at 50&#xa0;µg mL⁻¹ (others 100&#xa0;µg mL⁻¹); Sample B (5:3:2) reached 50&#xa0;µg mL⁻¹ only for <i>S. aureus</i>; Sample C (5:4:1) reached 50&#xa0;µg mL⁻¹ for <i>K. pneumoniae</i> and <i>P. aeruginosa</i>; ZnO alone inhibited <i>E. coli</i> at 50&#xa0;µg mL⁻¹; Ag and GO alone were 100&#xa0;µg mL⁻¹. These results point to a multi-target synergy—membrane perturbation, ion/ROS stress, and improved interfacial contact—enabled by the GO scaffold, supporting GO: Ag: ZnO as a practical route from simple PLAL-based synthesis to broad antimicrobial applications.</p>

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Graphene Oxide–Silver–Zinc Oxide Nanocomposites Prepared by PLAL and Ultrasonication: Synthesis, Structure, and Antimicrobial Activity

  • 期刊论文

  • 发表日期：

    2025年12月17日

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  • Yousra A. Hussein,
  • J. Al-zanganawee,
  • Esam H. Hummadi,
  • Oana Brincoveanu,
  • Cosmin Romanitan,
  • Raluca Gavrila

摘要

Bacterial and fungal infections remain a major global health challenge, exacerbated by the rise of antimicrobial resistance and the limited efficacy of conventional treatments. Although metal oxide nanoparticles of Zinc oxide and silver have the power to kill germs, but they don’t work as well since they don’t stay stable in colloidal form and clump together quickly, making it harder to control how nanoparticles spread. Because current preparation methods are hard to use, a clean, eco-friendly method is needed to get nanoparticles to be very stable and evenly spread out while also making them more effective against germ. Silver (Ag) and zinc oxide (ZnO) nanoparticles were prepared by pulsed laser ablation in liquid (PLAL) and subsequently integrated with graphene oxide (GO) by ultrasonication to yield ternary GO: Ag: ZnO nanocomposites at three weight ratios (5:2.5:2.5; 5:3:2; 5:4:1). Structural and surface analyses (XRD, FE-SEM/EDS, HR-TEM, FT-IR,. Raman Spectroscopy, UV–Vis, zeta potential) confirmed polycrystalline Ag (cubic) and ZnO (wurtzite) distributed on crumpled GO sheets with ~ 30–50 nm particle sizes(the standard deviation was found to be ± 10.6 nm, (Ag) and standard variation of ± 10.2 nm. (ZnO). TEM analysis confirmed that silver and zinc oxide particles were spherical, while that GO was in compact, overlapping sheets .FTIR and Raman results confirme the successful formation of GO–Ag–ZnO of the D and G bands. Zeta potentials (Ag ≈ − 32.04 mV, ZnO ≈ + 8.01 mV, GO ≈ − 43.25 mV) indicated stable Ag and GO colloids and comparatively lower stability for ZnO. Antimicrobial performance was assessed by agar well-diffusion against S. aureus and Candida albicans, and by minimum inhibitory concentration (MIC) against (S. aureus), Streptococcus spp., E.coli, Klebsiella pneumoniae, and (p.aeruginosa). In diffusion tests, all composites produced12 ± 0.47 mm zones for Staphylococcus aureus (S. aureus) at 0.2/0.3 µg mL⁻¹ and 14 ± 0.47 mm for C. albicans; the single-component Ag, ZnO, and GO were also active at these doses. In MIC assays, Sample A (5:2.5:2.5) inhibited Streptococcus spp. And E. coli at 50 µg mL⁻¹ (others 100 µg mL⁻¹); Sample B (5:3:2) reached 50 µg mL⁻¹ only for S. aureus; Sample C (5:4:1) reached 50 µg mL⁻¹ for K. pneumoniae and P. aeruginosa; ZnO alone inhibited E. coli at 50 µg mL⁻¹; Ag and GO alone were 100 µg mL⁻¹. These results point to a multi-target synergy—membrane perturbation, ion/ROS stress, and improved interfacial contact—enabled by the GO scaffold, supporting GO: Ag: ZnO as a practical route from simple PLAL-based synthesis to broad antimicrobial applications.