Persistent Photoinduced Antibacterial Activity of MoS₂ Nanosheets Immobilized in Porous Polymer Beads

Reactive oxygen species (ROS) photogenerated by two-dimensional (2D) nanomaterials provide a means of delivering persistent antibacterial activity in fluid media. Semiconducting molybdenum disulfide (MoS₂) nanosheets are an attractive option for exploiting such activity by using visible light. However, the tendency of MoS₂ nanosheets in suspension to restack or otherwise aggregate remains a critical obstacle, as it results in the loss of the desired photoactivity. We report here the development of persistent antibacterial activity by successfully immobilizing MoS₂ nanosheets within porous cross-linked polymer beads. The nanosheet-loaded beads demonstrate continuous antibacterial activity against model species under visible-light exposure. The bactericidal activity is associated with ROS-mediated oxidative organismal stress, as assessed through chemical methods using fluorescent probes and gene-level biological studies. The porous beads demonstrate an effective antifouling capability and were physically stable with sustained bactericidal activity at an average of 99% over 5 cycles. The ability to confer reusable, continuous antibacterial activity under visible-light illumination is attractive in the context of the development of sustainable solutions for photoinduced antibacterial materials.