Antibacterial Activity of Nanosilver Ions and Particles

作者：Sotiriou Georgios A; Pratsinis Sotiris E^*

来源：Environmental Science & Technology, 2010, 44(14): 5649-5654.

DOI：10.1021/es101072s

The antibacterial activity of nanosilver against Gram negative Escherichia colibacteria is investigated by immobilizing nanosilver on nanostructured silica particles and closely controlling Ag content and size. These Ag/SiO2 nanoparticles were characterized by S/TEM, EDX spectroscopy, X-ray diffraction the exposed Ag surface area was measured qualitatively by O-2 chemisorption. Furthermore, the fraction of dissolved nanosilver was determined by measuring the released (leached) Ag+ ion concentration in aqueous suspensions of such Ag/SiO2 particles. The antibacterial effect of Ag+ ions was distinguished from that of nanosilver particles by monitoring the growth of E. coli populations in the presence and absence of Ag/SiO2 particles. The antibacterial activity of nanosilver was dominated by Ag+ ions when fine Ag nanoparticles (less than about 10 nm in average diameter) were employed that release high concentrations of Ag+ ions. In contrast, when relatively larger Ag nanoparticles were used, the concentration of the released Ag+ ions was lower. Then the antibacterial activity of the released Ag+ ions and nanosilver particles was comparable.

• 出版日期2010-7-15