ABSTRACT
Electrogenerated chemiluminescence, also referred to as electrochemilumines cence or ECL, is gaining increasing recognition as an analytical tool as reflected in the growing number of publications presenting new applications of ECL for selective and sensitive detection of numerous substrates, including several re cent review articles [1-5]. The technique involves electrochemical generation of strongly oxidizing and reducing reactants that, upon annihilation, exhibit lumi nescence from an energetically accessible excited state of one of the reactant molecules. There are many reasons for the burgeoning interest in ECL sen sor technology. Detection of analytes can be performed using relatively simple instrumentation and inexpensive materials. In addition, the observation of lu minescence, particularly in the absence of an excitation light source, affords high sensitivity and a broad dynamic range. Since annihilation reactions, char acteristic of ECL, often occur at near diffusion limited rates, signal onset and equilibration are generally limited by factors other than reaction dynamics in ECL systems. As the variety of reactions leading to ECL continues to grow, the range of possibilities for development of ECL-based sensors is increasing
to envelop a wide variety of potential applications. The most fruitful employ ment of ECL in sensor development involves use of ruthenium diimine complex chromophores in the detection of biological molecules. Such complexes have been used in several commercially available sensors and examples of these ECL systems are presented in this chapter. The chapter begins with a discussion of fundamental aspects of electrogenerated chemiluminescence and is followed by a review of particular systems that have been used in sensor development.
