Augmented antibacterial efficacies of the aluminium doped ZnO nanoparticles against four pathogenic bacteria

Abstract

An ingenious study aimed to understand the influence of crystallite size, surface defects and morphology of the aluminium doped ZnO nanoparticles on their enhancement of antibacterial activities are reported herein. A cost effective wet chemical synthesis route was adopted for the synthesis of aluminium doped ZnO nanoparticles. X-ray diffraction analysis substantiates the hexagonal phase of the aluminium doped ZnO nanoparticles. The original contributions of the respective crystallite sizes and lattice strains of the synthesized nanoparticles are realized by size-strain plot (SSP) analysis. The UV-vis spectroscopic analysis revealed that the band gaps of the synthesized samples are widened on aluminium doping. The surface defects and vacancies present in the synthesized samples are revealed by the room temperature photoluminescence analysis. FESEM micrographs of the samples reveals that the crystallite sizes of ZnO decreases with the increase in aluminium content and a change in platelet to narrow sized spherical morphology. An investigation on the antibacterial activities of the aluminium doped ZnO nanoparticles was performed on Escherichia coli, Proteus mirabilis, Enterococcus faecalis and Staphylococcus aureus bacteria. The aluminium doping in ZnO leads to an enhanced antibacterial activity. The 5%Al:ZnO nanoparticle sample shows the highest antibacterial efficiency of 117% for the Proteus mirabilis bacterium. These results clearly demonstrate that the aluminium doped ZnO nanoparticles are promising candidates for antibacterial applications.