Pyrolyzed carbon biosenosor for aptamer-protein interactions using electrochemical impedance spectroscopy

We present an electrochemical biosensor utilizing pyrolyzed carbon as a working electrode for the aptamer-based thrombin detection. The pyrolyzed carbon is fabricated by photolithography and thermal decomposition of photoresist in an N₂ atmosphere. Physical and electrical properties of carbon thin film pyrolyzed with a positive photoresist, AZ9260, were studied for the biosensor application. Electron transfer resistance changes due to thrombin binding onto the carbon surface modified with thrombin aptamer were measured using electrochemical impedance spectroscopy techniques. Thrombin concentrations between 0.5 nM and 500 nM were detected by the electrochemical measurements.