Synthesis of NOM-Capped Silver Nanoparticles: Size, Morphology, Stability, and NOM Binding Characteristics

Silver nanoparticle synthesis produced by green chemistry methods shows potential in areas such as medical applications and biosensing. Here, we show that natural organic macromolecules (NOM) can be used to synthesize and stabilize silver nanoparticles (AgNPs). Silver nitrate was mixed with one of four NOM types that formed NPs by chemical reduction with either ascorbic acid or sodium borohydride. Resulting NP suspensions were characterized by size, morphology, and stability. A range of particle sizes were obtained, but no clear trends were observed for chemical type or NOM concentration. One reaction (10 mg L-1 HA, Ag+, and Na BH4) produced monodisperse and stable (after three months storage) AgNPs of 10-20 nm, while others such as succinoglycan could be relevant to application in other fields, e.g., medical research. This method indicates the potential to produce relatively stable AgNPs coated with a number of ligands from sustainable sources that are nontoxic and biocompatible, suitable for environmental risk study.