How Does Fluorescence Work?

This week Reactions is exploring the science behind fluorescence. There's a lot of chemistry behind what makes a fluorescent color stand out so brightly from the rest. Today we're digging into what makes them pop, and we're going highlight some of the brilliant applications of fluorescence coming out of nanotechnology.
Check out the NSF's Center for Sustainable Nanotechnology Blog!
sustainable-nano.com/
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Writer/Producer:
Kirk Zamieroski
Executive Producer:
Adam Dylewski
Scientific consultants:
Tom Kuech, Ph.D.
Miriam Krause, Ph.D.
Darcy Gentleman, Ph.D.
Music:
Sam Leopard - Secret Bass
Sam Leopard - Master of Gold
Sources:
How Do Highlighters work - sustainable-nano.com/2013/02/2...
What's in Highlighters: Pyranine -
www.compoundchem.com/wp-conten...
Chemistry-of-Highlighter-Pen-Colours.png
The Electromagnetic Spectrum - upload.wikimedia.org/wikipedi...
The Visible Light Spectrum - www.colormatters.com/color-an...
On Tonic water - www.livescience.com/36536-toni...
On Color -
www.livescience.com/32559-why-...
On Blacklights -
www.physics.org/article-questi...
Why flowers take up color from water - www.stevespanglerscience.com/l...
Nanodiamonds - sustainable-nano.com/2013/04/2...
Fluorescence and Forensics - forensics.org.my/img/Article%2...
Quantum Dots andI Imaging - www.ncbi.nlm.nih.gov/pubmed/18...
pubs.acs.org/doi/full/10.1021/...
Real-Time Background-Free Selective Imaging of Fluorescent Nanodiamonds in Vivo pubs.acs.org/doi/full/10.1021/...
Ever wonder why dogs sniff each others' butts? Or how Adderall works? Or whether it's OK to pee in the pool? We've got you covered: Reactions a web series about the chemistry that surrounds you every day.
Reactions is produced by the American Chemical Society.

[@willmcconnell6008]

Good video! But a technicality, I would say it's wrong in saying the dyes give back more energy, fluorescece is the absorption of a wavelength (color) of light (usually measured in nm) and the emission of a higher wavelength (aka different color). Higher wavelength means there's greater distance "between waves", which means the energy is lower/more spread out. Example, highlighters often use fluoroescein, which can absorb 498nm light, and emitts (reflects) ~521nm light (yellow green). The yellow-green light has 23 more nanometers between it's "waves of light", thus lower in energy. Tl;dr The dyes are emitting/reflecting a lower energy light/color back to your eyes, the dyes don't add energy. But great highlight on the topic!

[@josepeixoto3384]

Makes sense, not adding energy, thanks.

[@cholm2070]

Thanks, I was wondering how something could absorb light at a lower level and release it at a higher one without losing its own potential energy and functionality over time. This makes much more sense.

[@mrblackmamba117]

Amazing video. Thank you so much

[@cuajocuajocuajo]

I'm pretty sure fluorescent dyes don't release more energy than they absorb...they release higher wavelength light

[@kennethstudstill]

1:37 "This means the objects are giving back more energy than they received from the visible light source ..." It took me a moment to catch the word _visible_. The first part of the sentence appears to send the listener in the wrong direction, but it is correct.

[@cuajocuajocuajo]

Got it! "they are giving back more energy (light) than they received from the visible light source (when they are exposed to black light)". Basically comparing fluorescence intensity through excitation with visible light vs excitation with UV light source. that is correct. The sentence is not clear to my taste though. thanks!

[@Bnswiss]

Yes but what would cause this higher wave length of light to be released? By nature being higher on the electromagnetic spectrum means being higher in energy right? my knowledge of such principles is high school level at best.

[@FernandoJRodriguezFernandoJRM]

@@Bnswiss Energy of light is directly proportional to frequency, and inversely proportional to wavelength, meaning that a longer wavelength corresponds to lower energy.

[@hamidali5236]

@@Bnswiss not higher energy but higher wavelength

[@njintau]

Don't forget luminol, which aggressively binds to hemoglobin and fluoresces under UV. This allows investigators to find trace amounts of blood and can even reveal blood spots that were washed away.

[@Snakeyes244]

Incredible video

[@Eric-yj5xg]

All work and no play makes reaction team a dull team

[@delphoxoa9677]

Amazing

[@hognosemyan]

Also, most US currency has a very-hard-to-see plastic band that fluoresces to prevent counterfeiting.

[@tylerdeckate]

This is what I was looking for

[@PMcartoonworldintamil]

Very interested 👍

[@shalinitiwari119]

So anything that is fluorescent absorb UV light and gives off that light so we call it fluorescent .

[@Shuuyadesu]

Cool! The basic science development took place not more than aroung 500yrs ago (there were no proper science b4 that) but after the scientific development many things got changed

[@omermagen824]

OMG! I can see my math teacher here!!!

[@anamorphicalan]

I'm curious. Can I make a home brewed beer glow? As boil quinine for 15 min in a Pilsner. Could that work? Beer naturally is Opaque though

[@ACSReactions]

Sadly it wouldn't work. Fluorescing only works in clear liquids. The blue light is absorbed by the yellow/brown color of the beer and other molecules present might even kill the fluorescent effects. Plus most fluorescent dyes aren't something you'd want to drink--and the really good ones are downright toxic. Though there's probably some additives out there that could make your beer look like it's glowing.

[@jonathanmonkemeyer2693]

Will the highlighter eventually dim under the UV light due to it losing the excited state of energy over time?

[@mawile3037]

The chemicals causing it to do its magic would have to break down in order for the glow to fade

[@jonathanmonkemeyer2693]

@@mawile3037 this makes sense, thanks for the reply:) I don’t remember any of this from 3 yrs ago but I appreciate!

[@r6i6t6a6]

the speech could have been slower! good vedeo but the fast talk spoilt it all :(

[@nicholefieldbutch321]

Metallic, rose gold, etc

[@violette9706]

can you speak slowweeeeer in your next videos pleaaaase my brain is overwhelmed with information it cannot followwwww

[@Eric-yj5xg]

awewewewe

[@mawile3037]

Decrease the playback speed

[@cherrrriii]

Same

[@karltite128]

At least it ain't that robot talkin style. 🥃👀

[@michaeljacobdelossantos]

Why did the transcript from 0:51 just skipping after a second, someone needs to fix the TRANSCRIPT!

[@goodsir2551]

+Reactions , Quinine is not pronounced "quoanine" like you do at 1:54.. It's pronounced "Kee-neene"

[@tspoon772]

It’s pronounced Kwi-neen

[@AbhishekKumar-op5hn]

Watch at 0.75x to understand better

[@venkiteshvinod3197]

I have FABER-CASTELL highlighter and it does not have fluorescence

[@DeletriusX]

My fluorescent plastic glows in the sun

[@patrikznika8806]

😂

[@saniaafrin8506]

What is black light

[@yohaijohn]

Uv lighr

[@nessyandtot]

They do not release more energy than they absorb, it's actually less

[@NeverBeBored08]

Last time I was this early everyone thought France was gonna beat Portugal

[@humpty4205]

It is too fast.

[@denstasis3361]

Like, go to friends?

[@sfstucco]

I don't care how many times it's been said here, I feel the need to also say it: the speech is TOO FAST. No good for learning. Additionally, too many technical words ("jargon") are used without defining them, and sometimes even when they are not needed. I also find the quality of the information poor for teaching purposes. --- It's like someone actually believes children cannot pay attention long enough, so you had to pack everything in at warp speed so as to not lose their interest. I'll tell you that they came here interested in learning, but probably got overwhelmed with rapid-fire information & left them with nothing solid..

[@dcap8217]

Slow down! It’s not a race. If your point is to try and teach people about fluorescence you need to stop talking so fast. This would be especially helpful to those of us that are try to learn.

[@chelseamackintosh6047]

Would be a good video if he didn't speak to annoyingly fast.