Advances in nanotechnology provide opportunities for the prevention and treatment of
periodontal disease. While physicochemical properties of Ag containing nanoparticles (NPs) are known to influence the magnitude of their toxicity, it is thought that nanosilver can be made less toxic to eukaryotes by passivation of the NPs with a benign
metal. Moreover, the addition of other noble metals to
silver nanoparticles, in the
alloy formulation, is known to alter the
silver dissolution behavior. Thus, we synthesized
glutathione capped Ag/Au
alloy bimetallic nanoparticles (NPs) via the galvanic replacement reaction between
maltose coated Ag NPs and
chloroauric acid (
HAuCl4) in 5% aqueous triblock
F127 copolymer
solution. We then compared the antibacterial activity of the Ag/Au NPs to pure Ag NPs on Porphyromonas gingivalis W83, a key pathogen in the development of
periodontal disease. Only partially
oxidized glutathione capped Ag and Ag/Au (Au:Ag≈0.2) NPs inhibited the planktonic growth of P. gingivalis W83. This effect was enhanced in the presence of
hydrogen peroxide, which simulates the oxidative stress environment in the
periodontal pocket during chronic
inflammation.