Co-assembled ZnO-Fe2O3x-CuOx nano-oxide materials for antibacterial protection

Abstract

Metal oxide nanoparticles (MONPs) have been increasingly reported to possess diverse industrial and biomedical applications. Herein, we synthesized secondary (CuO, Fe2O3 (FeO), ZnO), ternary (ZnO/CuO-FeOx) and quaternary (ZnO-CuO-FeOx) co-assembled core-shelled MONPs by (co-)precipitation technique, characterized the synthesized MONPs and consequently investigated their antibacterial capacity. The UV-Vis absorption spectra of the prepared MONPs presented experimental band gaps; ZnO of 3.36 eV; ZnO-FeOx (x = 0.1; x = 0.5) with 3.38 eV and 3.37 eV; and ZnO-FeOx-CuOx (x = 0.1; x = 0.5) of 3.36 eV and 3.36 eV band gaps respectively. Thermogravimetric analysis revealed the stability of the prepared MONPs, by the presented total mass lost (%): ZnOFeO0.5 (1.34) > ZnOFeO0.1 (1.93) > ZnOFeO0.1CuO0.1 (2.12) > ZnOFeO0.5CuO0.5 (2.34) > CuOFeO0.1 (3.78) > CuOFeO0.5 (4.25) > Fe2O3 (4.44) > CuO (6.37) > ZnO (8.69). The XRD peak positions of the secondary MONPs prepared presented hexagonal structures for ZnO, monoclinic structures for CuO and rhombohedral structures for Fe2O3 without identified impurity peaks. Finally, the co-assembled MONPs prepared showed that they possessed varied efficiency for protection from different bacterial strains, with Staphylococcus.peumonia growth being the most inhibited, with MONPs treatments CuO > ZnOFeO0.5CuO0.5 > CuOFeO0.5 > ZnOFeO0.1CuO0.1 > Fe2O3 > ZnOFeO0.5 > ZnO.