From molecular electronics to proteonics: Break junctions for biomarker detection

Break junctions have emerged as an important tool to interrogate electrical transport properties of molecules. A number of approaches have been reported for the fabrication of break junctions, including optical/e-beam lithography, electromigration, and electrochemical deposition of conductive materials. All of these are either time consuming (due to slow e-beam writing) or give low yield. We report a novel method to fabricate a nanogap between two gold electrodes. A scratch made by focused ion beam (FIB) milling followed by electromigration provides rapid and high throughput break junctions. These nanogap break junctions are used to selectively capture and electrically detect cancer biomarker protein.