Enhancement of antibacterial properties of Ag nanorods by electric field

Abstract

The effect of an electric field on the antibacterial activity of columnar aligned silver nanorods was investigated. Silver nanorods with a polygonal cross section, a width of 20-60 nm and a length of 260-550 nm, were grown on a titanium interlayer by applying an electric field perpendicular to the surface of a Ag/Ti/Si(100) thin film during its heat treatment at 700• C in an Ar+H 2 environment. The optical absorption spectrum of the silver nanorods exhibited two peaks at wavelengths of 350 and 395 nm corresponding to the main surface plasmon resonance bands of the one-dimensional silver nanostructures. It was found that the silver nanorods with an fcc structure were bounded mainly by {100} facets. The antibacterial activity of the silver nanorods against Escherichia coli bacteria was evaluated at various electric fields applied in the direction of the nanorods without any electrical connection between the nanorods and the capacitor plates producing the electric field. Increasing the electric field from 0 to 50 V cm −1 resulted in an exponential increase in the relative rate of reduction of the bacteria from 3.9 × 10 −2 to 10.5 × 10 −2 min −1 . This indicates that the antibacterial activity of silver nanorods can be enhanced by applying an electric field, for application in medical and food-preserving fields.

PVD-grown antibacterial Ag-TiN films on piezoelectric PVDF substrates for sensor applications

“…Akhavan et al [18,19] reported two studies about the antibacterial effect of silver, one in which an electric field was applied in the direction of silver nanorods grown on a Ti interlayer deposited by dc magnetron sputtering, and another which reported compact Ag nanorods capped by sol-gel mesoporous TiO 2 layer, both deposited onto silicon substrates. The two studies showed a strong, fast and lasting antibacterial activity against Escherichia coli (E. coli).…”

Facile Synthesis of ZnO-Cu2O Composite Nanoparticles and Effect of Cu2O Doping in ZnO on Antimicrobial Activity

“…In recent times owing to advancement of some resistant bacterial strains to counter the antibiotics, the antibacterial activity of nanomaterials, such as zinc, silver and copper, with their unique size dependent properties has attracted great attentions [1][2][3][4][5]. For instance, ZnO with a quartzite hexagonal phase have a direct band gap of 3.37 eV possesses a wide range of technological applications.…”

Lasting antibacterial activities of Ag–TiO2/Ag/a-TiO2 nanocomposite thin film photocatalysts under solar light irradiation

“…However, before anything, silver itself is known as one of the most interesting antibacterial materials [17,[33][34][35][36][37]. It is generally believed Ag + can bind to bacterial cell wall membrane (slightly negative), damage it and so alter its functionality [38][39][40].…”