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New Evidence for Ag-Sputtered Materials Inactivating Bacteria by Surface Contact without the Release of Ag Ions: End of a Long Controversy?
Journal article

New Evidence for Ag-Sputtered Materials Inactivating Bacteria by Surface Contact without the Release of Ag Ions: End of a Long Controversy?

  • Rtimi S Ecole Polytechnique Fédérale de Lausanne, EPFL-STI-LTP , Station 12 , CH-1015 Lausanne , Switzerland.
  • Konstantinidis S Chimie des Interactions Plasma-Surface , Université de Mons , Place du Parc 23 , 7000 Mons , Belgium.
  • Britun N Chimie des Interactions Plasma-Surface , Université de Mons , Place du Parc 23 , 7000 Mons , Belgium.
  • Nadtochenko V N. Semenov Federal Research Center Chemical Physics , Russian Academy of Sciences , Kosygin Street 4 , Moscow 119991 , Russia.
  • Khmel I Institute of Molecular Genetics , Russian Academy of Sciences , Kurchatov sq.2 , Moscow 123182 , Russia.
  • Kiwi J Ecole Polytechnique Fédérale de Lausanne EPFL-GPAO , Bat GC, Station 6 , CH-1015 Lausanne , Switzerland.
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  • 2020-01-03
Published in:
  • ACS applied materials & interfaces. - 2020
Ag-coated surfaces
Ag-ionic species
HiPIMS/DCMS
genetically engineered bacteria
photocatalysis
redox catalysis
Anti-Bacterial Agents
Coated Materials, Biocompatible
Escherichia coli
Microbial Viability
Silver
Surface Properties
English The study provides new evidence for Ag-coated polyester (PES) mediating Escherichia coli inactivation by way of genetically engineered E. coli (without porins, from now denoted porinless bacteria). This allows the quantification of the bactericidal kinetics induced by the Ag surface without the intervention of Ag ions. Bacterial inactivation mediated by Ag-PES was seen to be completed within 60 min. The samples were prepared by high-power impulse magnetron sputtering (HiPIMS) at different sputter powers. In anaerobic media, this process required 120 min. The amounts of ions (Ar+, Ag+, and Ag2+) generated during the deposition by direct current magnetron sputtering (DCMS) and HiPIMS were determined by mass spectrometry. The thickness of the Ag films sputtered on PES by DCMS (0.28 A) during 100 s was found to be 340 nm. Thicknesses of 250, 230, and 200 nm were found when sputtering with HiPIMS was tuned at 8, 17, and 30 A, respectively. By scanning transmission electron microscopy (STEM-HAADF), the atomic distribution of Ag and oxygen was detected. By X-ray photoelectron spectroscopy (XPS), a shift in the Ag oxidation state was observed within the bacterial inactivation period. This reveals redox catalysis within the time required for the total bacterial inactivation due to the interaction between the bacterial suspension and Ag-PES. Surface properties of the Ag-coated PES samples were additionally investigated by X-ray diffraction (XRD). The formation of Ag plasmon was detected by diffuse reflectance spectroscopy (DRS) and was a function of the applied sputtering energy. The indoor sunlight irradiation dose required to induce an accelerated bacterial inactivation was found to be 5-10 mW/cm2.
Language
  • English
Open access status
closed
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Persistent URL
https://sonar.ch/global/documents/231667
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