Electrically conductive magnetic nanowires using an electrochemical DNA-templating route

Abstract

The fabrication of electrically conducting magnetic nanowires has been achieved using electrochemical DNA-templating of iron. In this approach, binding of the Fe²⁺ cations to the DNA “template” molecules has been utilised to promote growth along the molecular axis. Formation of Fe within the product material was verified by XRD and XPS studies, which confirmed an iron/oxide “core–shell” structure. The effectiveness of the DNA duplex to direct the metal growth in one dimension was highlighted by AFM which reveals the product material to comprise high aspect ratio nanostructured architectures. These “nanowires” were observed to have morphologies consisting of densely packed linear arrangements of metal particles along the template, with wire diameters up to 26 nm. The structures were confirmed to be electrically conductive, as expected for such Fe-based materials, and to display superparamagnetic behaviour, consistent with the small size and particulate nature of the nanowires.