Modulating the antibacterial activity of ZnO/talc by balancing the monodispersity of ZnO nanoparticles

The overuse or abuse of antibacterial drugs has led to serious health problems. At present, among various antimicrobial materials (natural, organic, inorganic, etc.), inorganic antimicrobial materials, especially ZnO, have received widespread attention. However, an important factor that influences the function of nanoparticles is agglomeration. The agglomeration-sensitive nature of ZnO compromises its antibacterial properties. Here, talc is used as a substrate to control the size and dispersion of ZnO, forming composite minerals with excellent antibacterial properties against both Escherichia coli and Staphylococcus aureus. According to transmission electron microscopy, ZnO/talc is easily adhered to bacterial cells, whereas atomic force microscopy reveals that antibacterial effects are caused by non-covalent interactions between ZnO/talc and bacterial membranes. The comprehensive investigation of antibacterial performance and interfacial interaction is conducive to our understanding of the antibacterial mechanism of inorganic compounds, and also provides new perspectives on the biological effects of inorganic nanomaterials. ZnO monodispersity on the surface of clay was modulated by the interface adsorption of ZnO-clay and the bacteriostatic mechanism of ZnO-clay composites was elucidated at the nano-scale. [Display omitted] •Clay mineral talc was used to support ZnO to prepare composite antibacterial material.•Biosafety of composite antibacterial material was evaluated in detail.•Antibacterial activity of ZnO/talc was modulated by balancing ZnO monodispersity.•Antibacterial mechanism was elucidated at the nano-scale.