Engineering Janus gold nanorod–titania heterostructures with enhanced photocatalytic antibacterial activity against multidrug-resistant bacterial infection

Photocatalytic antibacterial approach shows great potential in treating multidrug-resistant bacterial infections. However, the bactericidal efficiency heavily depends on the photocatalytic activity of semiconductor materials, which is limited by the fast recombination of photogenerated electron–hole pairs. Janus nano-heterostructures with spatial control growth of TiO₂ nanoparticles (NPs) at one end of gold nanorods (Au NRs) are designed via surface ligand regulation for photocatalytic sterilization and infected wound healing. The asymmetric nanostructure of Janus gold nanorod-titanium dioxide nanoparticles (Janus AuNR-TiO₂ NPs) promotes the directional migration of charge carriers and is more conducive to the spatial separation of electron–hole pairs. Moreover, the injection of hot electrons and enhancement of plasmon near-fields from the surface plasmon resonance (SPR) effect further improve the photocatalytic efficiency of Janus AuNR-TiO₂ NPs. Under simulated sunlight irradiation, large amounts of reactive oxygen species (ROS) are generated for photocatalytic antibacterial activity. Enhanced bactericidal efficiency up to 99.99% against methicillin-resistant Staphylococcus aureus (MRSA) is achieved in vitro. Furthermore, Janus AuNR-TiO₂ NPs exhibit superior biocompatibility, structural stability, and also remarkably accelerate MRSA-infected wound healing. Taking the above all into consideration, Janus AuNR-TiO₂ NPs, as an efficient antibacterial photocatalyst, offers a promising strategy for MRSA infectious therapy.