Solar-driven broad spectrum fungicides based on monodispersed Cu₇S₄ nanorods with strong near-infrared photothermal efficiency

The development of low-cost and biocompatible inorganic photothermal nanoagents with broadband sunlight absorption and high photothermal conversion efficiency as broad spectrum fungicides is highly desirable for the large scale antibacterial treatment especially in the wild, because of their highly efficient anti-bacteria ability via solar irradiation. Here, we present a facile strategy for the synthesis of Cu₇S₄ nanorods (NRs) with broadband light absorption (300-3300 nm) and high photothermal conversion efficiency (57.8%, 808 nm), and the use of these NRs as broad spectrum fungicides for efficient disinfection using natural sunlight as light source. In the presence of Cu₇S₄ NRs, with natural sunlight irradiation (70 mW cm^-2), both Gram-positive (S. aureus) and Gram-negative (E. coli) bacterium strains (2 mL, 10⁶ mL^-1) were completely killed in 10 min. These results suggest that our Cu₇S₄ NRs are effective and broad spectrum photothermal anti-bacterial agents regardless of drug resistance, that are particularly suitable for anti-bacteria activity in the wild using solar irradiation where artificial light sources are not available. Due to their strong near infrared (NIR) absorption, these biocompatible and low-cost Cu₇S₄ NRs may also serve as promising agents for photothermal therapy of tumors, disinfection in clinics, food sterilization and environmental treatment.