Functional Materials for Electrochemiluminescence Biosensors and Imaging

This doctoral thesis focuses on the investigation of innovative functional materials for the development of sensing applications, which use electrochemiluminescence (ECL) technology as transduction technique. The demand for highly sensitive, selective and reliable sensors able to perform fast, economic and easy detection in clinical and analytical chemistry increases constantly. Among the electrochemical techniques, ECL is the most suitable transduction method for sensing applications. In fact, due to the electrochemical nature of the signal generation, extremely high range of sensitivity and very low detection limits can be reached. Moreover, the generation of the signal is achieved directly in situ, which enables spatial visualization and mapping of the signal distribution. This property of the ECL can be exploited for the imaging of small objects, such as micro-particles or cells, deposited directly on the surface of the electrode. In addition, efforts have been made to understand the complex interplay of the chemical and electrochemical reactions responsible of the signal generation at the electrode surface. The collected information might help towards the improvement of the technology at the basis of the ECL sensors, in order to obtain higher sensitivity and selectivity. The functional materials studied in this thesis present different electrochemical characteristics and are expressly designed for sensor applications. In particular, the proper selection of the material and its optimization assure high performances of the device. For example, the combination of supramolecular chemistry with the ECL technology can be exploited for the development of a sensor for the early diagnosis of prostate cancer, or the excellent electrochemical properties of carbon-based materials can be used for the imaging of biological samples with high spatial resolution.