Bacterial elimination via cell membrane penetration by violet phosphorene peripheral sub-nanoneedles combined with oxidative stress

The effectiveness of an antibacterial agent is strongly influenced by its antibacterial mechanism, which, in turn, depends on the agent's topological structure. In the natural world, the nanoprotrusions on the surface of insect wings give them excellent antimicrobial properties through physical penetration while being compatible with host cells. Inspired by the novel nanostructure of insect wings, violet phosphorus (VP), a new member of the phosphorus family, has antibacterial potential due to the sub-nanoneedle on its edge. Here, we demonstrate that VP and its exfoliated product, violet phosphorene nanosheets (VPNSs), have superior antibacterial capability against pathogens via cell membrane penetration induced by peripheral sub-nanoneedles combined with oxidative stress. The results show that VPNSs can inactivate more than 99.9% of two common pathogens (Escherichia coli and Staphylococcus aureus) and more than 99.9% of two antibiotic-resistant bacteria (Escherichia coli pUC19 and methicillin-resistant Staphylococcus aureus), while showing almost no toxicity toward normal cells at a high concentration of 2.0 mg mL⁻¹. Moreover, VPNSs can achieve effective treatment of induced skin wound infections and bacterial keratitis (BK) by Staphylococcus aureus and methicillin-resistant Staphylococcus aureus, respectively, showing promising potential for ocular and skin wound infection theragnostics.