title: Silver confined within zeolite EMT nanoparticles: preparation and antibacterial properties.
abstract: The preparation of pure zeolite nanocrystals (EMT-type framework) and their silver ion-exchanged (Ag(+)-EMT) and reduced silver (Ag(0)-EMT) forms is reported. The template-free zeolite nanocrystals are stabilized in water suspensions and used directly for silver ion-exchange and subsequent chemical reduction under microwave irradiation. The high porosity, low Si/Al ratio, high concentration of sodium and ultrasmall crystal size of the EMT-type zeolite permitted the introduction of a high amount of silver using short ion-exchange times in the range of 2-6 h. The killing efficacy of pure EMT, Ag(+)-EMT and Ag(0)-EMT against Escherichia coli was studied semi-quantitatively. The antibacterial activity increased with increasing Ag content for both types of samples (Ag(+)-EMT and Ag(0)-EMT). The Ag(0)-EMT samples show slightly enhanced antimicrobial efficacy compared to that of Ag(+)-EMT, however, the differences are not substantial and the preparation of Ag nanoparticles is not viable considering the complexity of preparation steps.
authors.affiliation: Laboratoire Catalyse & Spectrochimie, University of Caen, CNRS, 6, boulevard du Maréchal Juin, 14050 Caen Cedex, France. svetlana.mintova@ensicaen.fr.
authors.forename: B
authors.initials: B
authors.lastname: Dong
authors.forename: S
authors.initials: S
authors.lastname: Belkhair
authors.forename: M
authors.initials: M
authors.lastname: Zaarour
authors.forename: L
authors.initials: L
authors.lastname: Fisher
authors.forename: J
authors.initials: J
authors.lastname: Verran
authors.forename: L
authors.initials: L
authors.lastname: Tosheva
authors.forename: R
authors.initials: R
authors.lastname: Retoux
authors.forename: J-P
authors.initials: JP
authors.lastname: Gilson
authors.forename: S
authors.initials: S
authors.lastname: Mintova
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D017641:Zeolites; D012834:Silver