title: 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+H2environment. 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 againstEscherichia colibacteria 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-1resulted in an exponential increase in the relative rate of reduction of the bacteria from 3.9×10-2to 10.5×10-2min-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.
authors.affiliation: Department of Physics, Sharif University of Technology, PO Box 11155-9161, Tehran, Iran.
authors.forename: Omid
authors.initials: O
authors.lastname: Akhavan
authors.affiliation: Tehran University of Medical Sciences, PO Box 14155-6447, Tehran, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Ghaderi
keywords: Ti thin film; antibacterial; nanorods; silver