We synthesized silver-gold (AgAu) bimetallic nanoparticles (NPs) via the galvanic replacement reaction between maltose coated silver NPs and HAuCl4 in 1-5% (w/v) triblock F127 copolymer solutions. This synthesis method is facile, economic, and environmentally benign.  Silver NPs are commonly used as antimicrobials but their antimicrobial efficacy is limited typically to aerobic conditions that produce silver ions (Ag+). Because of this, silver NPs are ineffective against anaerobes.  In the case of AgAu alloy NPs, the difference in redox potentials between Ag (~0.8 V) and Au3+ (~1.5V) results in surface sequestration of Ag+ ions that can be released into the solution under anaerobic conditions. We hypothesized that our synthesized AgAu NPs would exhibit antimicrobial activity against the anaerobic oral pathogen P. gingivalis. To test this hypothesis, we evaluated the effect of AgAu NPs on P. gingivalis planktonic growth rates, biofilm formation, and biofilm removal. AgAu NPs significantly inhibited P. gingivalis planktonic growth and biofilm formation. This inhibition was enhanced in the presence of hydrogen peroxide. Additionally, AgAu NPs significantly promoted P. gingivalis biofilm removal. These results suggest that AgAu NPs may be a promising therapeutic strategy against anaerobic pathogens.

Silver�gold alloy bimetallic nanoparticles as a therapeutic strategy against anaerobic pathogens

248th National Meeting (2014)

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