Applications of bioluminescence in biotechnology and beyond.

Bioluminescence is the fascinating natural phenomenon by which living creatures produce light. Bioluminescence occurs when the oxidation of a small-molecule luciferin is catalysed by an enzyme luciferase to form an excited-state species that emits light. There are over 30 known bioluminescent systems but the luciferin-luciferase pairs of only 11 systems have been characterised to-date, whilst other novel systems are currently under investigation. The different luciferin-luciferase pairs have different light emission wavelengths and hence are suitable for various applications. The last decade or so has seen great advances in protein engineering, synthetic chemistry, and physics which have allowed luciferins and luciferases to reach previously uncharted applications. The bioluminescence reaction is now routinely used for gene assays, the detection of protein-protein interactions, high-throughput screening (HTS) in drug discovery, hygiene control, analysis of pollution in ecosystems and in vivo imaging in small mammals. Moving away from sensing and imaging, the more recent highlights of the applications of bioluminescence in biomedicine include the bioluminescence-induced photo-uncaging of small-molecules, bioluminescence based photodynamic therapy (PDT) and the use of bioluminescence to control neurons. There has also been an increase in blue-sky research such as the engineering of various light emitting plants. This has led to lots of exciting multidisciplinary science across various disciplines. This review focuses on the past, present, and future applications of bioluminescence. We aim to make this review accessible to all chemists to understand how these applications were developed and what they rely upon, in simple understandable terms for a graduate chemist.