A near-infrared-activatable polyvinyl alcohol/chitosan composite hydrogel for efficient synergistic bacteria-killing

In this paper, PVA/CS/CuS-based antibacterial hydrogel was prepared by a simple method. The CuS-based particles were characterized using zeta potentiometers, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy. These analyses verified the successful synthesis of CuS@PDA and CuS@PDA@Ag particles. The composite hydrogel exhibited good photothermal effect and antibacterial activity, with silver doping significantly improving its photocatalytic performance. Under 808 nm near-infrared light irradiation, the hydrogel exhibited excellent photothermal conversion ability, with the maximum temperatures of the three hydrogels being 59.2 °C, 61.5 °C, and 64.8 °C, respectively. After 10-minute irradiation, the composite hydrogel exhibited obvious antibacterial activity due to the synergistic effect of hyperthermia and reactive oxygen species, resulting in a bactericidal efficiency of 96.2 % against E. coli and 98.4 % against S. aureus.