(165f) Ag/Cu Bimetallic Nanoparticle and Ion - Graphene Composites with Enhanced Antibacterial Performance

Increased proliferation of antimicrobial-resistant and new strains of bacterial pathogens severely impact current health, environmental, and technological developments demanding for design of novel, highly efficient antibacterial agents. Ag/Cu bimetallic nanoparticles (NPs) were in-situ grown on the surface of graphene, which was produced by chemical vapor deposition using ferrocene as precursor and further functionalized to introduce oxygen-containing surface groups. The antibacterial performance of the resulting hybrids was evaluated against Escherichia coli cells and compared through a series of parametrization experiments of varying metal type and concentration. It was found that both Ag- and Cu- based monometallic graphene composites significantly suppress bacterial growth, yet the Ag-based ones exhibit higher activity compared to their Cu-based counterparts. However, the bimetallic Ag/CuNP-graphene hybrids exhibit superior performance compared to all other materials tested, i.e. both the monometallic graphene structures as well as colloidal NPs, achieving complete bacterial inhibition in all metal concentrations tested. This striking performance is attributed to the synergistic action of the combination of the two different metals that coexist on the surface as well as the enhancing role of the graphene support. Analogous results were obtained with the respective elements were stabilized on the graphene oxide in form of surface-bound ions.