A clay-based Pickering nanoemulsion with antibacterial activity

Non-biotic antibacterial materials have drawn increasing attention. Some natural clays are able to promote the generation of reactive oxygen species, rendering them as promising candidates in combination with their abundant reserves, low cost and biosafety. However, the antibacterial performance of raw clay is usually below satisfaction due to poor solubility and restricted surface area. Hence, the modulation on dispersion form and the surface modification are essential for the design and practical application of natural clays as antibacterial materials. Herein, we developed a facile method to prepare a Pickering nanoemulsion with chitosan-coated montmorillonite (MMT) nanosheet. The addition of chitosan benefited the exfoliation of raw MMT and the stabilization of resultant colloidal MMT nanosheets, which were subsequently employed for preparing Pickering emulsion. The emulsion exhibited good stability and small size endowing them with good diffusion ability to interact with bacteria. Furthermore, the Pickering emulsion inherited the MMT nanosheet peroxidase-like property and displayed good antibacterial activity.