Plasmon-Enhanced Photocatalytic Activity of Organic Heterostructure for Indoor-Light Antibacterial Therapy

Semiconductor nanomaterials with photocatalytic activity have been considered as potential antibacterial materials against bacterial infection. Noble metal nanoparticles have been developed with semiconductors to promote their photocatalytic activities; however, the incorporation of noble metal NPs brings the risk of toxicity from the heavy metal species, especially for the widely used Ag nanoparticles (AgNPs). Herein, an all-organic chloridized g-C₃N₄/perylene-3,4,9,10-tetracarboxylic diimide (Cl-CNPD) heterostructure is chosen as a platform, in which the chloridized g-C₃N₄ provides bonding sites for uniform loading of AgNPs to prepare a plasmonic antibacterial nanocomposite. Benefiting from the in situ implanting approach, plasmon-induced light manipulation from the homodispersed AgNPs enables the nanocomposites to produce more reactive oxygen species (ROS), resulting in an antibacterial efficacy up to 96.1 ± 1.4% and 91.5 ± 1.8% against Staphylococcus aureus (S. aureus) under simulated sunlight (20 mW cm⁻²) and indoor light (5 mW cm⁻²) irradiation within 20 min, respectively, much higher than that of the organic heterostructure. Moreover, the strong interaction between the AgNPs and Cl-CNPD not only guarantees negligible toxicity by minimizing Ag leakage, but also shows high durability with unchanged efficacy after challenging bacteria up to five times repeatedly. Therefore, this confined plasmonic-based antibacterial nanocomposite shows great potential as a safe therapeutic system for wound disinfection.