Luminescent Materials
The world can be full of magic, and Dr. Russ Algar studies one magical concept. Think about fireflies or lightning bugs. These tiny insects flutter around our backyard, imitating the radiant stars in our skies. American poet Ogden Nash wrote about the firefly’s glow as an enigma: “The firefly’s flame is something for which science has no name” [1].
As science often does, it finds a reason for the unexplainable, for the seemingly magical aspects of our world. We, now, have a name for the firefly’s flame: bioluminescence. Many other organisms can glow. We can find bioluminescence in some bacteria, algae, fish, and sharks [2]. We can find them in organisms that fly above and that swim deep below the ocean.
What exactly is bioluminescence? In short, it is a chemical reaction that allows the emission of visible light. Species contain luciferin ((S)-2-(6′-hydroxy-2′-benzothiazolyl)-2-thiazoline-4-carboxylic acid), a compound that reacts with oxygen [3]. The energy released during this reaction is converted into visible light, ranging in color and intensity. Many organisms will also possess the catalyst luciferase which speeds up this reaction. Animals can use this light to communicate with others, lure prey, fool larger animals, and even attract mates. Inspired by bioluminescence in nature, scientists have worked on creating luminescent materials for interesting applications.
While bioluminescent proteins, such as Green Fluorescent Protein (GFP) derived from jellyfish, are widely used as genetic markers and in imaging techniques [4], luminescent nanomaterials provide unique benefits. Dr. Russ Algar and his lab work on developing such luminescent nanomaterials, which are nanoscale materials that emit light from the material upon excitation. They have numerous advantages, such as their tunable emission properties, that allow for more specific and promising detection [5]. To read about more of Dr. Algar’s exciting research on luminescent materials, such as quantum dots, find them here.
Applications in Fluorescence Spectroscopy and Medicine
A prominent use of luminescent nanoparticles is in fluorescent spectroscopy—which traditionally uses fluorescent dyes. Luminescent nanoparticles have raised significant attention in recent years as an alternative to these dyes [6]. First, what is fluorescence spectroscopy?
Fluorescence spectroscopy analyzes the fluorescent properties of the molecules or materials in a sample. The samples are excited with a photon source, which is a source that provides packets of light. Though molecules are commonly in the excited state, it is not energetically favorable for them to remain in this state. As a result, molecules return to a lower energy state through the emission of energy in the form of heat or in the case of fluorescence, light. This emission can then be characterized by its intensity [6]. The result of this technique is a fluorescence spectrum, which provides information about the fluorescent properties of a sample. This spectrum gives researchers information about a sample’s composition, structure, dynamics, and interactions with fluorescent molecules. As mentioned above, luminescent nanomaterials’ tunable emission properties allow them to serve as versatile probes and markers.
Another interesting application of luminescent materials is in medicine and accessible diagnostics. Dr. Russ Algar and his team have developed a smartphone-based platform that can isolate specific cell types using luminescent materials [6]. This revolutionary product could allow for improved healthcare that reduces wait times and inequities.
Learn More
If you’d like to hear more about the continually evolving field of luminescent nanomaterials as well as their exciting applications in medicine, visit us on Spotify, Apple Podcasts, and many other streaming services to listen to our ChemTalk podcast with Dr. Russ Algar, Associate Professor of Chemistry at the University of British Columbia and avid studier of those that glow.
Find the ChemTalk podcast here.
Works Cited
[1] The Firefly by Ogden Nash. All Poetry. (n.d.). https://allpoetry.com/poem/8496517-The-Firefly-by-Ogden-Nash
[2] Bioluminescence. Smithsonian Ocean. (2023, May 11). https://ocean.si.edu/ocean-life/fish/bioluminescence#:~:text=Bioluminescence%20is%20found%20in%20many,the%20ability%20to%20light%20up
[3] Oba, Y., Yoshida, N., Kanie, S., Ojika, M., & Inouye, S. (2013). Biosynthesis of firefly luciferin in adult lantern: Decarboxylation of ʟ-cysteine is a key step for benzothiazole ring formation in Firefly Luciferin Synthesis. PLoS ONE, 8(12). https://doi.org/10.1371/journal.pone.0084023
[4] Marshall, J., Molloy, R., Moss, G. W. J., Howe, J. R., & Hughes, T. E. (1995). The jellyfish green fluorescent protein: A new tool for studying ion channel expression and function. Neuron, 14(2), 211–215. https://doi.org/10.1016/0896-6273(95)90279-1
[5] Dong, R., Li, Y., Li, W., Zhang, H., Liu, Y., Ma, L., Wang, X., & Lei, B. (2019). Recent developments in luminescent nanoparticles for plant imaging and photosynthesis. Journal of Rare Earths, 37(9), 903–915. https://doi.org/10.1016/j.jre.2019.04.001
[6] Algar, Russ. Personal Interview. Conducted by Olivia Lambertson and Riya Jain. 15 May 2023.