Nanostructured materials as substrates for the development of biosensors
This thesis describes the experiments performed to evaluate the suitability of different types of electrodes towards the development of electrochemical biosensors. Commercial electrodes (electrodes containing carbon nanotubes and electrodes of indium tin oxide) were initially considered for detection of H2O2 (a byproduct of many enzymatic reactions) at low potentials in reduction mode. These electrodes did not show significant advantages with respect to traditional electrodes, even after selected surface modifications were performed. On the other hand, optically transparent carbon electrodes (fabricated by adsorption/pyrolysis of proteins) showed remarkable advantages towards the development of electrochemical biosensors. These electrodes were characterized by a combination of electrochemical, optical, and spectroscopic techniques. As a proof-of-concept, the optically transparent carbon electrodes were used as electrochemical transducers for the development of a glucose biosensor based on the oxidation of H2O2.