Green and facile synthesis of aminated lignin-silver complex and its antibacterial activity

Silver nanoparticles (AgNPs) exhibit broad spectrum antibacterial effect, but their cores after use can persist in the environment, which presents a toxic effect on humans. To address this issue, silver-based biomaterials are regarded as green alternatives to AgNPs. In this study, we used kraft lignin, a green and biodegradable polymer derived from wood biomass, to prepare an aminated lignin-silver complex ([email protected] complex) as an alternative antibacterial agent. A facile approach for preparing aminated lignin (AL) was realized by the amination of kraft lignin using 2-chloroethylamine hydrochloride in water solvent. The nitrogen content of optimized AL was 4.37 %. Ag(Ⅰ) could be captured and reduced to metallic Ag(0) by AL, thereby forming AgNPs on the surface of AL. Importantly, the obtained [email protected] complex was proven to be an effective antibacterial agent against gram-positive (Bacillus cereus, Staphylococcus aureus) and gram-negative (Salmonella enterica) bacteria.