Silver doped TiO<sub>2</sub> nanoparticles (Ag/TiO<sub>2</sub>) were synthesized by the photochemical
reduction of silver nitrate with oxalic acid and ultraviolet (UV) radiation in the presence of TiO<sub>2</sub> (Degussa P-
25). Inactivation of Bacteriophage MS-2 by the Ag/TiO<sub>2</sub> nanoparticles, the parent TiO<sub>2</sub> material,
and silver nanoparticles (nAg) were assessed in small batch systems subjected to UV-A
radiation. The viral suspensions were assayed via the double agar layer method. The results
obtained with silver doped TiO<sub>2</sub> were compared with those obtained with TiO<sub>2</sub> alone, nAg alone,
and UV-A alone to determine if the presence of Ag enhances viral inactivation by TiO<sub>2</sub> and if a
synergism exists between the antiviral activity of nAg and that of TiO<sub>2</sub>. Chick's law was used to
model the inactivation kinetics. Ag/TiO<sub>2</sub> initially inactivated MS-2 faster than bare TiO<sub>2</sub>, with a
rate constant of 0.17 s<sup>-1</sup> vs. 0.12 s<sup>-1</sup>, respectively. However, a tailing effect was observed with
the Ag/TiO<sub>2</sub>, and the inactivation rate slowed after 20 s of irradiation, corresponding to
approximately 3.5 LOG removal. nAg alone and UV-A alone were not found to significantly
inactivate MS-2, supporting the hypothesis that a synergism occurs between nAg and TiO<sub>2</sub> when
combined. The understanding of the inactivation mechanisms will be used for the development
of highly efficient Ag/TiO<sub>2</sub> materials for virus inactivation. Includes 22 references, figures.
| Edition : | Vol. - No. |
| File Size : | 1
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| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 11/01/2008 |
