Antimicrobial Properties of Glass Surface Functionalized with Silver-doped Terminal-alkynyl Monolayers

Abstract

Glass discs functionalized with alkynyl (GDA) terminated monolayers were prepared and incubated in AgNO 3 solution (GDA-Ag). The modified functional glass surfaces were characterized by X-ray photoelectron microscopy (XPS). The potential of GDA and GDA-Ag as antimicrobial surfaces was investigated. Antimicrobial efficacies of GDA against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Candida albicans was relatively low ranging from 4.67 to 17.00%. However, the GDAAg was very effective and its antimicrobial efficacy ranged from 99.90 to 99.99% against the same set of microbial strains except for C. albicans where it was 95.50%. The durability of the Ag bonded to the terminal alkynyl groups was studied by placing the GDA-Ag in PBS buffer solution (pH 7.4) for two weeks. Initially, the silver release was relatively fast, with 40.05 ppb of silver released in first 24 h followed by a very slow and constant release. To study the potential of GDA-Ag for medical applications, in vitro cytotoxicity of GDA-Ag against Human Embryonic Kidney 293 (HEK293) cell lines was studied using WST-assay. The cytotoxicity of the GDA-Ag was very low (5%) and was almost comparable to the control (blank glass disc) indicating that GDA-Ag has a promising potential for medical applications.

Promoting the Generation of Active Oxygen over Ag-Modified Nanoflower-like α-MnO2 for Soot Oxidation: Experimental and DFT Studies

“…Since the surface Mn 3+ /Mn 4+ ratio and surface oxygen vacancies [V o ] are important factors affecting the generation of O x n – , the electronic states and [V o ] of the catalysts were examined using XPS. The binding energies (BEs) at 368.1 and 374.1 eV of Ag 3d in Ag(10)-NF are contributed by Ag 3d 5/2 and Ag 3d 3/2 , respectively, which are related to metallic Ag (Figure a) . It can also be proved by the splitting of 6 eV as well as the high symmetry of the spectra. , Gas-phase oxygen (O 2 ) can be transformed into active oxygen species (O – or O 2 – ) over metallic Ag, which are then involved in the reaction. , These results suggest the presence of Ag in the metallic state, which confirmed the result that the peaks of Ag 0 of Ag(10)-NF in the XRD spectra are invisible, which may be due to its high dispersion.…”

“…The binding energies (BEs) at 368.1 and 374.1 eV of Ag 3d in Ag(10)-NF are contributed by Ag 3d 5/2 and Ag 3d 3/2 , respectively, which are related to metallic Ag (Figure 6a). 41 It can also be proved by the splitting of 6 eV as well as the high symmetry of the spectra. 28,42 Gas-phase oxygen (O 2 ) can be transformed into active oxygen species (O − or O 2 − ) over metallic Ag, which are then involved in the reaction.…”