Metalloprotein-based field-effect transistor: a prototype

A key challenge in nanoelectronics is the use of a bottom-up approach to fabricate nanodevices from molecular building blocks. Here, a field-effect transistor based on the metallo-protein Azurin is demonstrated. Azurin is attractive because of its natural redox properties (provided by the Cu redox site) and self-assembly capability (which allows the chemisorption on suitable surfaces). Our prototype structure consists of two planar nanoelectrodes connected by a protein self-assembled monolayer and a back electrode as gate. The transfer characteristic exhibits a pronounced resonance and transport is explained in terms of equilibrium between the two possible oxidation states of the copper site.