1. STEM workshop Illuminating Life: What's New and Noteworthy in Luminescence Spectroscopy and Imaging
Pat O’Hara
October 3, 2009

2. Emission of Light Incandescence Luminescence Triboluminescence
YES
After heating? NO
Incandescence
Luminescence
After excitation with sound?
After using mechanical forces?
YES
YES
Triboluminescence
Sonoluminescence
After excitation with light?
YES NO
Immediately?
Inanimate?
YES NO
YES NO
fluorescence
phosphorescence
chemiluminescence
bioluminescence

3. What is fluorescence? http://micro.magnet.fsu.edu/primer/
Fluorescence is the emission of a photon by an excited state molecule.

4. What’s new in fluorescence?
Fluorescence of gemstones used to detect fake diamonds
Fluorescence is key to spider sex in some species
Fireflies chemiluminescence
Deep Sea Bioluminescence-
Bananas that glow: Fluorescence of ripening fruit is key to cellular processes

5. Beware jewel theives! Real diamonds fluoresce

8. Fluorescence of Plants
Ultraviolet fluorescence of plants is detected by bees, who have photoreceptors in this region of the spectrum and can see what looks to us like landing patterns on the petals directed towards pollen

9. Emission of Light Incandescence Luminescence Triboluminescence
YES
After heating? NO
Incandescence
Luminescence
After excitation with sound?
After using mechanical forces?
YES
YES
Triboluminescence
Sonoluminescence
After excitation with light?
YES NO
Immediately?
Inanimate?
YES NO
YES NO
fluorescence
phosphorescence
chemiluminescence
bioluminescence

10. What is chemiluminescence?
Chemical reaction results in an intermediate that is in an excited state.
Reaction goes to product after this intermediate releases a photon
Energy of the photon comes from chemical energy due to the difference in energy of reactants and products

11. What is Chemiluminescence?
Example 1: Chemistry of Lightsticks
Phenol + CO2 + Dye + Light

12. What is Chemiluminescence?
Example 2: Chemistry of the Luminol Reaction
Oxidants: Peroxide, bleach, hemoglobin
light
3-aminophthalhyrazide
Catalysts: sodium perborate, cupric chloride,

13. Emission of Light Incandescence Luminescence Triboluminescence
YES
After heating? NO
Incandescence
Luminescence
After excitation with sound?
After using mechanical forces?
YES
YES
Triboluminescence
Sonoluminescence
After excitation with light?
YES NO
Immediately?
Inanimate?
YES NO
YES NO
fluorescence
phosphorescence
chemiluminescence
bioluminescence

14. Firefly Bioluminescence

15. What is Bioluminescence?
Chemistry of the Luciferase Reaction
In the dark cycle (quiescent) oxygen is consumed by mitochondria (green) and ATP and luciferin are stored up in peroxisomes.
In the flash cycle, (NO) is released, and prevents consumption of O2 by mitocondria. Instead, O2 diffuses to peroxisome and voila! A flash!!

16. What is Bioluminescence?
Chemistry of the Luciferase Reaction
The luciferase catalyzes the oxidation of luciferin
Resulting in light and an inactive "oxyluciferin"

17. Luciferase
luciferase

18. Bioluminescence from surface water
Animal------Jellyfish near surface
Small algae called milky sea

19. Bioluminescence from mid-water range
Let’s see video clip……….
Mid-water … ft deep
light intensity decreases exponentially
250 ft 10% less than surface
500 ft 1% less than surface
Plants can not photosynthesize
Why do organisms emit this light?
1. defense against predators
2. camouflage
3. see things and find food
4. communicate

20. Giant Squid- caught in action in 2007
There are 100 known genera of squid and cuttlefish, 63 of which produce bioluminescence. Cephalopods possess light-producing organs called photophores, which can be arranged in simple clusters or in complex organs containing lenses, reflectors and light filters. In some cephalopods, light is produced by symbiotic bacteria which are housed and cultured within pockets in the skin; other species produce the light themselves.
Squid also use bioluminescence to avoid being detected by predators. In a process called countershading, they turn on downward- facing photophores when illuminated from above; when the intensity of the bioluminescence matches that of the overhead illumination, the squid becomes invisible.
Bioluminescence is produced when pigment molecules called luciferins are oxidized (i.e. have electrons removed from them). This reaction is carried out by enzymes called luciferases, which are believed to have evolved from oxygenases. The function of luciferases and oxygenases is to transfer electrons from one molecule to another, and they are therefore involved in neutralizing free radicals (compounds which contain unpaired electrons, and which are damaging to tissues). In the deep sea environment there is little light, and organisms are therefore not exposed to free radicals produced by direct sunlight as are organisms which live nearer the surface. Neutralization of free radicals is therefore not crucial in deep waters, and this is where luciferases evolved their light-producing functions.
The photophores found in T. danae measure up to 5 cm in diameter and are the largest found in the animal kingdom. They are equipped with black “eyelids” which can open and shut rapidly, so that the emitted light appears to flash on and off.

21. Bioluminescence from deep sea jellies

22. Green Fluorescent Protein GFP
GFP is a small very fluorescent protein isolated from the bioluminescent jellyfish, Aequorea victoria. This protein glows or fluoresces green when it absorbs blue light emitted from another protein in the jellyfish, aqueorin.

23. Fluorescent Bomb Throwing Marine Worm
“fast, agile swimmers with glistening, translucent bodies sprouting rows of bristles that work like paddles. When disturbed, they eject glowing, green blobs that probably serve as decoys to distract predators’”

24. Pat’s Picks Bizarre deep ocean sea creatures:
Deep sea luminescent animals:
UCSB links:

25. Milky Sea Captured on Satellite Image off coast of East Africa

26. Glowing bananas: photo credit: Zina Deretsky, National Science Foundation

27. Glowing bananas: photo credit: Zina Deretsky, National Science Foundation

28. Your Banana Challenge
I’ve brought in two dozen bananas of various stages of ripeness, some common solvents, knives, jars, and a black light.
I’d like us to explore this phenomenon and put together some discovery lab questions that –with a black light and a ripe banana, might be useful to you in your lab.