Facile fabrication of Gracilaria spinulosa extract-mediated zinc/copper oxide nanocomposite for antimicrobial applications

Bimetallic nanocomposites represent an important class of nanomaterials with diverse applications in optoelectronics, catalysis, bioimaging, and antimicrobial therapy. In the present study, Gs@Zn/Cu nanocomposites were synthesized via a green synthesis approach. Gracilaria spinulosa seaweed extract was employed to simultaneously load zinc/copper nanoparticles, utilizing its bioactive components as reducing and binding agents. Antibacterial assays demonstrated that the synthesized nanocomposite possesses notable antibacterial activity against Escherichia coli and Staphylococcus aureus . The combination of zinc and copper produced inhibition zones of 20 mm against E. coli and 16 mm against S. aureus . Antibiofilm assays indicated that the Gs@Zn/Cu nanocomposite reduced approximately 85% of biofilm formation at the lowest tested concentrations. Artemia biosafety assays indicated that the synthesized Gs@Zn/Cu nanocomposites are non-toxic and may be suitable for clinical applications. Collectively, these results suggest that bioactive Gs@Zn/Cu nanocomposites have considerable potential as antimicrobial and biomedical materials.