Antimicrobial activity of ZnO-TiO2 nanomaterials synthesized from three different precursors of ZnO: influence of ZnO/TiO2 weight ratio

In this study, ZnO-TiO 2 nanoparticles were synthesized from three different precursors for ZnO (zinc acetate di-hydrate, zinc nitrate hexahydrate and zinc sulfateheptahydrate) and titanium (IV) isopropoxide for TiO 2 . The prepared nanomaterials were calcined at 500 °C for 3 h and characterized by various physicochemical techniques such as X-ray diffraction, Fourier Transform Infra Red spectroscopy and transmission electron microscopy, combined with energy dispersive X-ray spectroscopy. The obtained results showed that the crystalline structure, size and morphology of the ZnO-TiO 2 nanoparticles are strongly influenced by the nature of the precursor of ZnO, as well as the ZnO/TiO 2 weight ratio. The antibacterial and antifungal activities of the synthesized nanomaterials were evaluated, in the dark, against five multi-resistant of Gram positive ( Staphylococcus aureus) and Gram negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella paratyphi A ) bacteria and a fungus ( Candida albicans ), which are pathogenic for humans. The obtained results showed that pure TiO 2 anatase is inactive against the tested strains, while the addition of ZnO to TiO 2 improves noticeably the effectiveness of TiO 2 nanoparticles, depending on the nature of the precursor of ZnO and the ZnO/TiO 2 weight ratio.