Green synthesis of silver nanoparticles with enhanced antibacterial activity using holocellulose as a substrate and reducing agent

Silver nanoparticles (AgNPs) with relatively uniform size and well-defined structure have been synthesized by a hydrothermal method with holocellulose (HC) as a substrate and reducing agent for silver ions. This method was simple, cost-effective and convenient to handle without use of any other stabilizing or reducing agents. The as-prepared HC/Ag nanocomposites exhibited good cytocompatibility to cells and were highly toxic to microorganisms. The antibacterial activity studies were carried out on both Gram-positive S. aureus and Gram-negative E. coli bacteria by a disc diffusion method and an agar dilution method. The important role of HC and the influence of the additional reducing agents (NaBH4 and ascorbic acid) on the products were systematically investigated, and the formation mechanism of HC/Ag nanocomposites was proposed. These results indicate that HC is a good candidate for the preparation of silver-based nanocomposites, and the as-prepared HC/Ag nanocomposites may have potential for use in a wide range of biomedical applications.