Antibacterial Activity of Partially Oxidized Ag/Au Nanoparticles against the Oral Pathogen Porphyromonas gingivalis W83

Figure 1

Materials characterization of Ag and Ag/Au nanoparticles. Atomic force microscopy images of (a) Ag ( nm; ) and (b) Ag/Au ( nm; ) nanoparticles with height distributions. Transmission electron microscopy images of (c) Ag and (d) Ag/Au nanoparticles. The nanoparticles were prepared by adding HAuCl₄ (0.2 M, 1 μL) to 1 mL of Ag NP seed solution (). (e) UV-vis absorption spectra of Ag, Au, a mixture of Ag and Au, and Ag/Au nanoparticles normalized to their peak maxima. (f) Infrared spectra confirming glutathione chemisorption on the surface of Ag/Au NPs. Glutathione (0.1 mM, 10 μL) was added to Ag/Au nanoparticles in 1 mL 5% w/v F127 and left for ≈12 hours. The nanoparticles were washed by centrifugation (10000 ×g; 20 minutes) in water twice before analysis.