10 Fluorescence Examples in Daily Life to Explore Light

Fluorescence examples in daily life are actually quite abundant. Many times, we can’t see if something is really fluorescent or not unless we shine a blacklight on it. Still, these fluorescent objects in our daily lives will be brightly colored, and often described as “neon.” (Not to be confused with actual “neon lights,” which are not fluorescent.)

You can know something exhibits fluorescence when it glows under blacklight. These are the excitation wavelengths used in labs for fluorescence as well. The short-wavelength, blue/violet colored light will trigger molecules to fluoresce if they have the capability to do so. You can read more about how fluorescence is linked with the blue-colored light in my History of Fluorescence article.

1. Butterflies

The Heliconius butterfly’s wings are confirmed to fluoresce, as has been demonstrated in studies. Many types of “swallowtail” butterflies are also suspected to have fluorescent wings.

In addition to fluorescence, many butterflies also exhibit iridescence. This is a separate phenomenon, characterized by a “shiny” coating. Shells like abalone also have iridescence.

2. Glowsticks

The key component in glowsticks allowing them to fluoresce is their oxalate esters. These react with the hydrogen peroxide fluid to create an electron acceptor. When the molecule accepts the electron, the energy state drops into a more stable configuration. Whenever energy state drop, the energy is released, in this case, in the form of fluorescent light.

Slightly different chemicals are used to create the different colored glowsticks. Remember, fluorescence happens when a molecule absorbs a photon, and then drops back down in energy states again, releasing the photon with a shift in color (the Stokes shift.) So to create the different colors, molecules are chosen based on the wavelength of photon they will release.

3. Diamond jewelry

Diamonds fluoresce under blacklight if they have trace amounts of the element Boron in them. This happens in about a third of diamonds, according to jewelers. The diamonds that do not have these trace Boron aberrations are more pure, and thus more expensive.

The diamonds that fluoresce have a more milky color that a jeweler can recognize in normal lighting. This doesn’t affect the sparkle much, as the diamond’s sparkle is mainly due to the cut.

4. Tonic Water (quinine)

In tonic water, quinine is added, its main characteristic ingredient. Quinine is derived from tree bark, of the genus Cinchona. This tree, known as the “fever tree,” gave chewable bark to people who shivered in cold, as the tales go. Quinine is a malaria treatment as well.

The quinine in tonic water gives it that bitter taste. It’s very diluted, so it won’t help you if you have malaria. Tonic water is also often sweetened now to actually mitigate the bitter flavor somewhat.

5. Laundry Detergent

Laundry detergent is commonly that bright blue or purple color. This is to discourage consumption, but the bright additives used are naturally fluorescent. as well. This class of molecules are called optical brighteners, and are used in all kinds of commercial products. Often, optical brighteners come from either class of molecules “stilbenes” or biphenols.

But it’s not only for the look of the laundry detergent before it’s used. These optical brighteners deposit into our clothing and give a brighter appearance. to the colors. The bluish purple tint cancels out any dirty yellow tinges. The downside is that these optical brighteners are not really safe for humans or our waterways. While not all of them have been studied, at least 50 have been banned. They don’t biodegrade, potentially disrupt hormones, and irritate some people’s skin.

6. Cash security strips

Higher value bills have a security strip, visible in normal lighting added. There are also many security indicators on bank notes that only glow under black light. This is why some cash registers have a black light pen nearby, so they can check legitimacy of larger bills.

The blacklight reactive fluorescent indicators on cash discourage counterfeits and make it simple to detect the real thing. Fluorescent chemical dyes are easily added to create the effect. Each denomination also has a different configuration of threads, causing it to glow differently under the bulb.

7. Aquarium pets

There are many biological examples of fluorescence. In daily life, we see aquariums where the fish are very brightly colored. Many types of fish have fluorescent molecules in their scales.

Because fish have different vision receptors than we do, these fluorescent fish scales probably evolved as signals to other fish. Aquarium enthusiasts seek out different types of fluorescent fish for the visual effect. Some varieties of fish with fluorescent scales, even bioengineered to induce this (patented as GloFish), include:

• Zebra danios
• Many species of Betta fish
• Black skirt tetras
• Tiger barbs
• Rainbow shark

8. Bodily Fluids

Yes, the gross part. Bodily fluids, most notably pee and sperm (also known as cum), glow under blacklight. Some products to detect pet urine stains are a simple blacklight pen. Blood and feces also has this fluorescent property.

Bodily fluids glow mainly because of the phosphorus content. Phosphorous containing rocks were some of the first studied in the discovery of fluorescence. Vitamin A, as well as B vitamins thiamine, niacin, and riboflavin are all strongly fluorescent. Since pee and sperm are the highest in these compounds, they will glow the most.

9. Printer paper

Like the laundry detergents above, printer paper uses optical brighteners, after bleaching of the fibers, to make it was white as possible. If you look at regular printer paper under a blacklight, it will glow lightly purple.

So it’s not just neon rave flyers that glow. All paper brands will exhibit this slightly differently, but if the paper is standard white, it will fluoresce due to the optical brighteners.

10. Street signs

Street signs have fluorescent coatings, strips, and dyes to optically brighten them as well. This results in a reflective effect when hit with headlights at night. The fluorescent property is really an incidental byproduct, like the laundry detergent.

Street signs hit with a blacklight will surely glow, especially traffic cones. In many examples here, you can see how fluorescent molecules confer brightness even in ordinary lighting conditions.

The Ever-Present Fluorescence Examples in Daily Life

Fluorescent objects are often the very vividly colored things around us. This is by no means a comprehensive list, so you may find more fluorescence examples in daily life, now that you know what to look for.