Enhanced in vitro antibacterial activity of ZnO and Mn–Mg co-doped ZnO nanoparticles: investigation of synthesis, characterization, and impact of dopant

A simple and cost-effective co-precipitation method was used to develop zinc oxide (ZnO) and dual metal (Mn, Mg) co-doped ZnO nanoparticles (NPs). The impact of dual doping on the structural, morphological, and optical properties of ZnO NPs was investigated using a variety of characterization approaches. The wurtzite phase of ZnO was confirmed by X-ray diffraction. The findings demonstrated that (Mn2+, Mg2+) ions could replace Zn2+ ions without affecting the wurtzite structure of the ZnO. With the increase in the (Mn, Mg) doping concentrations, the crystallites size is also increased. According to the scanning electron microscopy and energy dispersive spectroscopy results, the dual metal is effectively incorporated into the ZnO lattice, and the elements zinc (Zn), oxygen (O), manganese (Mn), and magnesium (Mg) compounds were found in the doped NPs. The band gap increased due to the doping and the prepared NPs were p-type in nature. The antibacterial activity of the samples was tested using the diffusion well method against Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumonia) bacteria. When compared to other samples, the higher amount of (Mn, Mg) doping exhibits higher antibacterial activity.