Introduction and Overview of Electrogenerated Chemiluminescence
This chapter is a general introduction to electrogenerated chemiluminescence (ECL) for those without prior knowledge of the subject, but with a background in chemistry or biochemistry. The major processes, methods and concepts discussed in this chapter provide a foundation for an initial understanding of ECL. After a simple classification of the different types of luminescence, we present the underlying principles of ECL in electrochemistry and photophysics. The basic energetic and kinetic aspects, which involve exergonic electron-transfer reactions are then introduced and briefly described by the Marcus theory. We then consider the different mechanistic pathways leading to the generation of the electronically excited state of the luminophore. This is followed by a short presentation of the main protagonists: the electrode materials, where ECL is initiated, the nature of the luminophores and of the coreactants. Finally, the sensing strategies are presented with the main (bio)analytical applications, which are successfully commercialized.