Enhanced Bactericidal Activity of Silver Thin Films Deposited via Aerosol-Assisted Chemical Vapor Deposition

Abstract

Silver thin films were deposited on SiO2-barrier-coated float glass, fluorine-doped tin oxide (FTO) glass, Activ glass, and TiO2-coated float glass via AACVD using silver nitrate at 350 °C. The films were annealed at 600 °C and analyzed by X-ray powder diffraction, X-ray photoelectron spectroscopy, UV/vis/near-IR spectroscopy, and scanning electron microscopy. All the films were crystalline, and the silver was present in its elemental form and of nanometer dimension. The antibacterial activity of these samples was tested against Escherichia coli and Staphylococcus aureus in the dark and under UV light (365 nm). All Ag-deposited films reduced the numbers of E. coli by 99.9% within 6 h and the numbers of S. aureus by 99.9% within only 2 h. FTO/Ag reduced bacterial numbers of E. coli to below the detection limit after 60 min and caused a 99.9% reduction of S. aureus within only 15 min of UV irradiation. Activ/Ag reduced the numbers of S. aureus by 66.6% after 60 min and TiO2/Ag killed 99.9% of S. aureus within 60 min of UV exposure. More remarkably, we observed a 99.9% reduction in the numbers of E. coli within 6 h and the numbers of S. aureus within 4 h in the dark using our novel TiO2/Ag system.

Durable Antimicrobial Behaviour from Silver-Graphene Coated Medical Textile Composites

“…The images indicate fibrous surfaces decorated with AgNP agglomerates of polydisperse distributions in shape and diameter, attached to rGO sheets [90,91]. It is important to note that particles observed on the textile surface via SEM comprise a collection of Ag crystallites and, thus, are much larger than the crystallite sizes estimated by the Scherrer equation [92]. The primarily spherical agglomerations observed in this case are also reflected in the UV-Vis data where there is no observable lateral plasmon shift signal.…”

The fabrication of the antibacterial paste based on TiO2 nanotubes and Ag nanoparticles-loaded TiO2 nanotubes powders

“…The XRD pattern of Ag/TNTs powder still appears as characteristic peaks of anatase and rutile phases. Besides, Figure 4(b) shows that these observations at 38.2 and 44.4 have represented (111) and (200) planes of the face-centred phase of silver metal [11,16]. These results demonstrated that the Ag NPs existed within the TNTs.…”

“…The results of the Ag3d XPS ( Figure 5(d)) have the following spotlight: first, the sample had more common smaller peaks inside the two top large spectra. After using Gaussian fit to analyse the XPS spectra of Ag 3d, there is appearance of peaks at 367.5, 368.6, 371.8, and 375 eV with binding energy positions corresponding to Ag + 3d 5/2 , Ag 0 3d 5/2 , Ag + 3d 3/2 and Ag 0 3d 3/2 , respectively [16,31]. This shows that there is an existence of two states of silver including Ag + and Ag 0 .…”

“…There are many nanomaterials used to fight bacteria, but the combination of silver nanoparticles (Ag NPs) with TiO 2 has been studied a lot, recently [6][7][8][9][10][11][12][13]. Ag/TiO 2 not only possesses significant bactericidal activity under dark conditions but also enhances its self-cleaning [14][15][16]. The photoactivity of Ag/TiO 2 is greatly enhanced because Ag NPs are believed to both enhance photoactivity by facilitating electron-hole separation, and visible light absorption due to silver surface plasmons that are thought to induce electron transfer to TiO 2 [10,11,17,18].…”

Integration of bio-responsive silver in 1D photonic crystals: towards the colorimetric detection of bacteria

“…Within this context, silver is widely recognised and employed as a bio-responsive plasmonic material. [32][33][34] The bactericidal activity of silver seems to be linked to the strong electrostatic adhesion between the negatively charged bacterial outer membrane and the positively charged silver ions, followed by efficient Ag + uptake inside the bacterial cells. [35][36][37] We have preliminarily determined that this might lead to a modication of Ag charge carrier density and shi of the plasmon resonance upon E. coli/Ag interaction.…”