Preparation of Lignosulfonate@AgNPs Colloidal Nanocrystal Clusters through In Situ Reduction, Confined Growth, and Self-Assembly

Abstract

Herein, colloidal nanocrystal clusters (CNCs) formed from lignosulfonate (LS) and Ag nanoparticles (LS@ AgNPs) were prepared by in situ reduction, confined growth, and self-assembly methods. The LS micelles in solution served as a confined nano-reactor for the growth of AgNPs, and the phenolic hydroxyl groups in the structure provided complex sites as well as played a reducing role for the Ag ions. Following the addition of cetyltrimethyl ammonium bromide and anti-solvents, LS colloidal nanoparticles were achieved through self-assembly of LS micelles, and the AgNPs in the micelles entered the inner phase, forming the core@shell CNCs. However, the AgNPs in the CNCs were large in size (50 nm), few in number (<10 n/n), and unevenly distributed. The reason for this may be the low reduction ability of LS resulting in the loss of controlled growth of AgNPs in LS micelles. In contrast, the extra addition of a strong reducing agent significantly decreased the size of AgNPs and led to their more uniform distribution in the CNCs. Furthermore, LS@AgNPs CNCs showed good antibacterial activity, especially against Staphylococcus aureus (+). We expect these green, sustainable composite nanoparticles can be further applied in many other fields as well.

Solvent-Induced Lignin Conformation Changes Affect Synthesis and Antibacterial Performance of Silver Nanoparticle

“…In recent years, there has been growing interest in the synthesis of silver nanoparticles using lignin as a reducing agent and stabilizer [ 25 , 26 ]. Lignin-based silver nanoparticles offer several advantages over traditional AgNPs, including enhanced biocompatibility [ 27 ], reduced cytotoxicity [ 28 ], and improved stability [ 29 ]. Furthermore, the functional groups present in lignin can impart additional properties to the nanoparticles, such as improved dispersibility [ 30 ] and targeted delivery [ 31 ].…”

“…Table S1. Comparison of synthesis methods and particle size of AgNPs@AL [ 7 , 8 , 21 , 27 , 28 , 43 , 52 , 53 , 54 ].…”