What is the Difference Between Bioluminescence and Fluorescence

The key difference between bioluminescence and fluorescence is that bioluminescence is the emission of light by living organisms, whereas fluorescence is the emission of light by materials.

Bioluminescence and fluorescence are related chemical concepts where both processes emit light energy due to a particular reaction. However, they are different from each other according to the source of light and chemical reaction.

CONTENTS

1. Overview and Key Difference
2. What is Bioluminescence
3. What is Fluorescence
4. Bioluminescence vs Fluorescence in Tabular Form
5. Summary – Bioluminescence vs Fluorescence 

What is Bioluminescence?

Bioluminescence is the biochemical emission of light by living organisms. It is a type of chemiluminescence. This emission mainly occurs in marine vertebrates and invertebrates. However, we can observe bioluminescence in some fungi species, microorganisms such as bioluminescent bacteria, terrestrial arthropods (fireflies), etc.

Generally, the chemical reaction that takes place during bioluminescence is the reaction between a light-emitting molecule and an enzyme. This enzyme usually is known as luciferase. Correspondingly, the reactant molecule is known as luciferin. We can use these terms to distinguish the bioluminescent animal species: e.g. firefly luciferin. During this chemical reaction, the enzyme tends to catalyze the oxidation of the reactant substance.

Sometimes, the enzyme requires a cofactor to work. Examples of cofactors include calcium and magnesium ions. These reactions sometimes need energy-carrying molecules such as ATP. Throughout the evolution, the structure of luciferin varied very little.

There are slight differences in luciferin and luciferase components, which makes few common features in the chemical mechanism of the bioluminescence. The general chemical reaction is as follows:

Luciferin + O2 → oxyluciferin + light energy

What is Fluorescence?

Fluorescence is the emission of light from a substance that has absorbed energy previously. These substances have to absorb light or any other electromagnetic radiation to emit light as fluorescence. Furthermore, this emitted light is a type of luminescence, meaning it emits spontaneously. The emitted light often has a longer wavelength than the absorbed light. That means the emitted light energy is lower than the absorbed energy.

During the process of fluorescence, light is emitted as a result of the excitation of atoms in the substance. The absorbed energy is often released as luminescence in a very short time period, about 10^-8 seconds. That means we can observe fluorescence as soon as we remove the source of radiation that cause excitation.

There are many applications of fluorescence in different fields, such as mineralogy, gemology, medicine, chemical sensors, biochemical research, dyes, biological detectors, fluorescent lamp production, etc. Moreover, we can find this process as a natural process as well; for example, in some minerals.

What is the Difference Between Bioluminescence and Fluorescence?

Bioluminescence is the biochemical emission of light by living organisms, while fluorescence is the emission of light from a substance that has absorbed energy previously. The key difference between bioluminescence and fluorescence is that bioluminescence is the emission of light by living organisms, whereas fluorescence is the emission of light by materials.

The following infographic lists the differences between bioluminescence and fluorescence in tabular form for side by side comparison

Summary – Bioluminescence vs Fluorescence

Bioluminescence and fluorescence are related chemical concepts where both processes emit light energy due to a particular reaction. However, they are different from each other according to the source of light and chemical reaction. The key difference between bioluminescence and fluorescence is that bioluminescence is the emission of light by living organisms, whereas fluorescence is the emission of light by materials.

Reference:

1. “Bioluminescence.” National Geographic Society, 9 Oct. 2012.

Image Courtesy:

1. “Photinus pyralis Firefly glowing” By art farmer from evansville indiana, usa – firefly w/ glow (CC BY-SA 2.0) via Commons Wikimedia
2. “Fluorescent minerals hg” By (Hgrobe 06:16, 26 April 2006 (UTC)) – credit: Hannes Grobe/AWI – Own work (CC BY-SA 2.5) via Commons Wikimedia