Effect of stabilizers on composition and stability of bimetallic copper/silver nanoparticles

The study investigated processes of bimetallic copper/silver nanoparticle formation in aqueous media using two reducing agents: sodium borohydride and ascorbic acid. Adding these reducing agents in sequence allows the synthesis of bimetallic nanoparticles at room temperature. The influence of stabilizing agents such as sodium dodecyl sulfate, cetyltrimethylammonium bromide, and oleic acid and their combinations on the composition of nanoparticles in suspensions and the stability of suspensions was examined. When using a combination of oleic acid and sodium dodecyl sulfate, bimetallic copper/silver nanoparticles with a preset composition of 4:1 were formed. These nanosized systems remain stable for at least 3 months. The proposed synthetic method allows the fabrication of copper/silver nanoparticles ranging in size from 30 to 40 nm. The studied nanoparticles were shown to completely inhibit the colony growth of E. coli and S. aureus test strains on dense nutrient media when diluted to 10%, with exposure times of 3 and 5 h.