Antibacterial activity of copper-doped montmorillonite nanocomposites prepared by alkaline ion exchange method

Abstract

The antibacterial activity of copper-doped montmorillonite nanocomposites (Cu-MMT) has been investigated. Copper loaded clay nanocomposites have been synthesised by alkaline ion exchange processes in media containing copper sulfate at 550°C. Characterisation studies on the composites were done by X-ray diffractometry (XRD), scanning electron microscope (SEM) and absorption spectra analysis. SEM results indicated the diffusion of copper to the inner montmorillonite layer and opening of presenting cracks on its surface. The XRD analysis showed the presence of copper oxide (CuO) structure intercalated within the clay mineral layers. The antimicrobial effects of doped montmorillonite powders against pathogen bacterial strains Escherichia coli and Staphylococcus aureus were tested in broth media. Quantitative test in liquid media clearly showed that copper-doped samples had viable cells reduction ability for testing strains. The excellent antimicrobial activity of the composites was observed on S. aureus. In addition, the composite showed good stability in water and good promise for use in water treatment.