Antibacterial Activities of Ethiopian Natural Honey Against Iron and Nickel-Doped ZnO Nanoparticles

Abstract

In this work, the antibacterial activities of natural Ethiopian honey and iron (Fe)-/nickel (Ni)-doped ZnO nanoparticles against Gram-positive and Gram-negative bacteria were investigated. The test strains used were Staphylococcus aureus (S. aureus ATCC25923) and Escherichia coli (E. coli ATCC25922). The co-precipitation method was used to prepare Fe- and Ni-doped ZnO nanoparticles (NPs). The X-ray diffraction (XRD) study revealed that the prepared samples have hexagonal crystal structure with a preferred orientation along the (101) plane. The average crystal sizes for iron and nickel-doped NPs were 39.09[Formula: see text]nm and 34.30[Formula: see text]nm, respectively. The energy dispersive analysis of X-ray spectra (EDX) analyses confirmed the presence of Zn, O, Fe and Ni elements in the prepared NPs samples. A strong emission peak at 454[Formula: see text]nm was observed in the photoluminescence spectra of the NPs. In order to characterize the honey’s composition, variety of physico-chemical and optical approaches were used. The absorption spectra of the three samples of honey are comparable and exhibited a noticeable peak about 260[Formula: see text]nm. The FTIR analysis confirmed that the honey samples contained the expected functional groups. The agar well diffusion technique was used to investigate the antibacterial efficacy of Fe- and Ni-doped ZnO NPs as well as Ethiopian natural honey. The results show that against E. coli strains and S. aureus strains, respectively, Fe-doped and Ni-doped ZnO NPs had average inhibitory zones of 17.1[Formula: see text]mm, 15.7[Formula: see text]mm, 15.5[Formula: see text]mm and 14.7[Formula: see text]mm, respectively. Against the S. aureus strain, the natural honey displayed a maximal inhibition zone of 12.6[Formula: see text]mm and no inhibition zone at all for E. coli.