Chemiluminescence vs. Bioluminescence

Question

Luminescence in general, is the term of emission of light from specific substances/objects. Chemiluminescence is the emission of light due to chemical reactions. Bioluminescence on the other hand is the emission light from living/biological organisms such as insects ( this is of course the way I understood them ), but I'm a little bit confused because what is the cause that makes insects emmit light? Doesn't that also have to do with chemical reactions but inside living organisms ?

Just a clear explanation of the difference between these two terms would be helpful.

Answer 1

Doesn't that also have to do with chemical reactions but inside living organisms?

Exactly! That's why there is one scientific society for both phenomena: ISBC - International Society for Bioluminescence and Chemiluminescence ;-)

The thermal reactions, that lead to an excited species which eventually emits a photon are quite similar. From a reactive compound, typically called a luciferine, a four-membered ring, often a dioxetanone is formed. This decarboxylates and gives rise to a molecule in an electronically excited state. In reality, the decarboxylation is often not just a spontaneous process but requires an activator. W. J. Baader at IQUSP in Sao Paulo, Brazil has examined that in great detail.

The luciferines can be quite different compounds, such as

• diaryloxalates (these are used in glow sticks, where the diferent colours come from diferent fluorphores that absorb the initial photon and emit at different wavelength)
• benzothiazole derivatives (firefly)
• triazine derivatives (marine organisms)