Silver nanoparticles (AgNPs) have been intensively investigated and widely used in consumer products such as textiles, personal care, and food storage containers for their potent antibacterial capacity (Dadosh, 2009, Xiu et al., 2011). Recently, a number of studies of the antibacterial property of AgNPs have been reported. Xiu et al. demonstrated that AgNPs could kill E. coli by releasing Ag+ ions from the oxidized surface (Xiu et al., 2012). It was found that the antibacterial activity of nanosilver was dominated by Ag+ ions when fine AgNPs (less than about 10 nm in average diameter) were employed that release high concentrations of Ag+ ions. In contrast, when relatively larger AgNPs were used, the concentration of the released Ag+ ions was lower (Sotiriou & Pratsinis, 2010). Song et al. reported the synthesis of silver/polyrhodaninecomposite-decorated silica nanoparticles and their antibacterial activity. The silver/polyrhodanine-nanocomposite-decorated silica nanoparticles exhibited excellent antimicrobial activity toward gram-negative Escherichia coli and gram-positive Staphylococcus aureus because of the antibacterial eects of the AgNPs and the polyrhodanine (Xiu et al., 2011).