Principles and recent analytical applications of chemiluminescence

The potentials and possibilities offered by the rather unknown chemilumines cence-based analytical technique are discussed. Simplicity of instrumentati on, low detection limits for various systems, and the inherent power of app lication to a vast number of natively fluorescing species or fluorophores f ormed after chemical derivatization broaden the scope of this relatively ne w detection technique. Drawbacks should be mentioned as well, amongst other s limited selectivity of analysis (unless coupled to a powerful separationa l set-up), unexpected poor sensitivities for various analytes and the need to include an extra reaction step in the analytical procedures. Apart from the earlier gas-phase applications, the analysis in flowing streams (flow i njection analysis, HPLC, and even capillary electrophoresis) has increased exponentially starting back in the early eighties. Various reagents have be come available, including some originating from bioluminescent reactions (e .g. for ATP- and related analysis), not to forget the light emission as pro duced by diverse oxidation reactions, many of which the exact chemical path ways are not elucidated yet. On top of this, the power of chemiluminescence induction and measurements as applied to immunoassays, in the development of sensors, and, even more important, in the fast developing area of microm achining (sub-droplet-sized capillary electrophoresis) are discussed.