Antibacterial activity against Escherichia coli and characterization of ZnO and ZnO-Al2O3 mixed oxide nanoparticles

In order to achieve better antibacterial water insoluble nanoparticles (Nanoparticles) of ZnO and ZnO-Al2O3 were studied. ZnO-Al2O3 mixed oxide nanoparticles were produced from a solution containing Zn(AC)2⋅2H2O and AlCl3 by Solvothermal method. The calcination process of the ZnO-Al2O3 composite nanoparticles brought forth polycrystalline one phase ZnO-Al2O3 nanoparticles of 30-50 nm in diameters. ZnO and ZnO-Al2O3 were crystallized into würtzite and rock salt structures, respectively. The structural properties of this sample were analyzed by XRD and compared with bulk case of these samples. Antibacterial effectiveness of the ZnO and ZnO-Al2O3 nanoparticles were tested against general Escherichia coli (E. coli ATCC 25922) and E. coli O157:H7 by measuring the growth through optical density and digital counting of live-dead cells. Minimum inhibitory concentration values against four representative bacteria along with E. coli O157:H7 were also obtained.