Construction of a Rapid Photothermal Antibacterial Silk Fabric via QCS-Guided <i>In Situ</i> Deposition of CuSNPs

Abstract

Natural textiles provide an ideal environment for bacterial growth, causing harm to human health. In order to overcome this issue, a photothermal antibacterial technique has been employed as a facile strategy in recent years. Copper sulfide nanoparticles (CuSNPs) exhibit a satisfactory photothermal effect and can be potentially used to construct antibacterial textiles. Herein, we prepared a photothermal antibacterial silk fabric via a two-step method, where a chitosan quaternary ammonium salt (QCS) was used as a template to temporarily fix negative sulfur ions, which were transferred to silk fibers containing copper ammonia ions. The morphology, structure, and corresponding antibacterial ability for the obtained CuSNP-deposited silk fabric were examined. The obtained results revealed that the prepared materials, formed by interactions with silk fibers and QCS chains, exhibited uniform size and typical structural characteristics, promoting UV resistance and a good light-to-heat conversion effect. Moreover, a rapid antibacterial efficiency of the composite silk fabric was determined under light irradiation (400 mW/cm2), resulting in 99.99% bacteria death of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) within 5 min of irradiation. Additionally, the antibacterial rate of CuSNP-deposited with QCS as a template (SF/QCS/CuS) remained at a high level even after 10 washes, indicating a rapid bonding rate of the photothermal nanoparticles. This work develops a novel and efficient strategy for the construction of a photothermal antibacterial silk fabric, which expands its wide applications in the field of antibacterial materials.