A bioinspired approach to the fabrication of nanostructured functional devices is described. ZnO nanowires are formed by self-assembly of nanosized ZnO building blocks controlled by tobacco mosaic virus (TMV) templates at nearly ambient conditions. This process allows the integration of TMV/ZnO nanostructures into field-effect transistors (FETs) with prestructured electrodes. The FETs operate as-deposited, without further treatment.