Funzionalizzazione elettrochimica di substrati per applicazioni di interesse industriale

The present PhD project, focused on the functionalization of materials useful for industrial applications, is divided into two main parts: the first part concerns the electrochemical functionalization of gold for the immobilization of DNA in sensoristic applications; while the second one deals with the modification of porous nano silicon used as a substrate for the electrochemical polymerization of polyaniline and melanin for photovoltaic applications. The common theme of these two macro-topics is the electrochemical reduction of diazonium salts on metal or polymeric electrodes, immediately before the DNA attack and the modifications with polyaniline or melanin respectively. All the functionalizations, and the surface characterizations, which will be dealt in detail in the following chapters, have been mainly realized with electrochemical techniques: in particular the cyclic voltammetry technique has been used to realize the grafting process of the organic molecules on the electrode surface , and with the same technique we proceeded for the polymerization of aniline and melanin. All the phases of modification and functionalization have been characterized using electrochemical impedance spectroscopy (EIS), which provides rapid and important information about the surface layer. In this thesis the results of the electrochemical functionalizations and the performances of the modified electrodes that vary with the variation of the preparation conditions and the set electrochemical parameters are shown and discussed.