Fabrication of highly stable silver nanoparticles using polysaccharide-protein complexes from abalone viscera and antibacterial activity evaluation

Silver nanoparticles (AgNPs) are eco-friendly antibacterial agents, yet their use is limited by their facile aggregation and precipitation. Therefore, the development of highly stable AgNPs is desirable. Herein, a polysaccharide–protein complex (PSP) was successfully obtained from viscera of abalone through a combination of enzymatic hydrolysis, membrane filtration, and gel permeation chromatography. Furthermore, highly stable AgNPs were successfully synthesized by using PSP as a reducing and capping agent in situ. AgNPs were firmly capped by PSP through the formation of AgO, AgN, and AgS bonds, as observed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning transmission electron microscopy. Such capping of AgNPs by PSP contributed to the stable dispersion of PSP-AgNP composites at room temperature for 12 months, as evidenced by visual inspection and multiple light scattering. Furthermore, PSP-AgNPs were found to have an excellent antibacterial activity and biocompatibility. The proposed synthesis of AgNPs with high antibacterial activity, dispersibility, and biocompatibility will be of likely benefit in the field of life science and technology. •Polysaccharide was the major proportion of PSP.•AgNPs were prepared by using PSP as reducing and capping agent.•High dispersibility and antibacterial activity was found in AgNPs-PSP.•A schematic model was presented for AgNPs-PSP interactions and complex structures.