Gold Nanorod-Decorated Metallic MoS₂ Nanosheets for Synergistic Photothermal and Photodynamic Antibacterial Therapy

Light-responsive nanocomposites have become increasingly attractive in the biomedical field for antibacterial applications. Visible-light-activated metallic molybdenum disulfide nanosheets (1T-MoS₂ NSs) and plasmonic gold nanorods (AuNRs) with absorption at a wavelength of 808 nm were synthesized. AuNR nanocomposites decorated onto 1T-MoS₂ NSs (MoS₂@AuNRs) were successfully prepared by electrostatic adsorption for phototherapy applications. Based on the photothermal effect, the solution temperature of the MoS₂@AuNR nanocomposites increased from 25 to 66.7 °C after 808 nm near-infrared (NIR) laser irradiation for 10 min. For the photodynamic effect, the MoS₂@AuNR nanocomposites generated reactive oxygen species (ROS) under visible light irradiation. Photothermal therapy and photodynamic therapy of MoS₂@AuNRs were confirmed against E. coli by agar plate counts. Most importantly, the combination of photothermal therapy and photodynamic therapy from the MoS₂@AuNR nanocomposites revealed higher antibacterial activity than photothermal or photodynamic therapy alone. The light-activated MoS₂@AuNR nanocomposites exhibited a remarkable synergistic effect of photothermal therapy and photodynamic therapy, which provides an alternative approach to fight bacterial infections.