Near-Infrared-Activated Efficient Bacteria-Killing by Lignin-Based Copper Sulfide Nanocomposites with an Enhanced Photothermal Effect and Peroxidase-like Activity
Yuanxiang Xie, Yong Qian, Zhixian Li, Zicong Liang, Weifeng Liu, Dongjie Yang, Xueqing Qiu
Abstract
Lignin has been considered to be an ideal carrier for the construction of lignin-based antibacterial materials by its biocompatibility and environmentally benign feature. Herein, lignosulfonate (LS) was utilized as a growth template and a stabilizing agent to synthesize lignin-copper sulfide (LS-CuS) nanocomposites. Interestingly, the as-prepared LS-CuS nanocomposites show enhanced photothermal performance and peroxidase-like activity with near-infrared (NIR) light activation, which benefits highly efficient bacteria-killing via synergistic photothermal–catalytic effects. The bactericidal tests indicated that LS-CuS nanocomposites (100 μg/mL) cause 5.9-log10 and 5.4-log10 CFU/mL reductions against Escherichia coli and Staphylococcus aureus under NIR light irradiation (808 nm, 1.8 W/cm2) for only 5 min in the presence of H2O2. Moreover, LS-CuS nanocomposites can be blended with waterborne polyurethane (WPU) to obtain hybrid films, which also achieves a bactericidal efficacy of more than 90% in 5 min. Considering the low cost, easy preparation, and environmental friendliness of LS-CuS nanocomposites, this study may provide new insights into the design of lignin-based inorganic nanocomposites with high bacteria-killing efficiency in a sustainable manner.