Integrated horizontal ZnO nanowires for sensor applications

We describe the route to grow an array of horizontal ZnO nanowires between two predefined electrodes on silicon oxide surface at low temperature (<;100 °C) using hydrothermal technique. The single crystalline nanowires are 40-60 nm thick and long enough to provide the electrical paths over the gap of several micrometers. The achieved nanowires are gatable by the silicon substrate as back-gate with on-off current ratio of more than 10
³
. Such device shows a current increase of about six orders of magnitude upon exposure to 365 nm UV-light, and can be modulated by IgG with concentration as low as 25 nM.