Synthesis, characterization and antibacterial activity of simple ZnO and metal doped ZnO nanoparticles

The objective of this study was to synthesize pure ZnO and metal doped ZnO nano-particles, determine its physical, chemical characteristics and antibacterial activity against selected bacterial strains. Pure ZnO was synthesized and metals including Manganese (Mn), Magnesium (Mg), Calcium (Ca), Copper (Cu) and Silver (Ag) were doped with ZnO to produce nanoparticles through co-precipitation method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used for detection of synthesized nanoparticles, their crystalline structures, size and other chemical characteristics. An altered version of Kirby Bauer method of disk diffusion was used for determining the antibacterial activity of these nanoparticles. The XRD results showed that the average size of pure ZnO nanoparticles was 55.3 nm. While the size of metal doped ZnO particles were affected by dopant elements. Results of SEM indicated that these nanoparticles were roughly spherical, rod shape and fiber like rod shape with certain degree of aggregation. Antibacterial studies showed that all samples had the potential to inhibit the growth of selected bacterial strains; E. coli, S. choleraesuis, S. typhimurium, S. marcescens, B. subtilus and S. aureus. With 90μg/ml concentration ZnO nanostructures inhibited B.subtilus and silver doped Zinc nanoparticles suppressed growth of S. marcescens. Characterization and antibacterial study indicated the importance of these nanoparticles at industrial and pharmaceutical level.