Anyone know about flourescent dyes?

  • Thread starter johnintheuk
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In summary, the conversation is discussing the search for dyes with high quantum yields and minimal photobleaching rates. Perylene based dyes are currently considered the best option, with a yield approaching 100% and low photobleach rates. Quantum dots also have reasonable yield and low photobleach rates compared to most dyes. The discussion then shifts to understanding the photobleaching mechanisms, including the role of photoxidation and triplet states. The confocal listserver is mentioned as a source of further information on photobleaching. It is noted that quantum dots do not photobleach due to a different fluorescence mechanism. The person asking the question is looking for recommendations on other dyes to consider and inquires about the application
  • #1
johnintheuk
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I'm looking for dyes that have exceptionally high quantum yields and minimal photobleaching rates.

So far, perylene based dyes seems to be the best. Their yield approaches 100% and exhibits the low photobleach rates I mentioned.

Quantum dots have reasonable yield and great photobleach rates compared to most dyes.

Anyone understand the photobleaching mechanisms in more detail? I realize there is a photoxidation factor, which caused the dye / dots to oxidize under photo exposure. But even when oxygen is excluded, many dyes (dots included) appear to bleach out of fluorescence somehow. I've seen it mentioned that this is caused by intense excitation causing triplet states to appear. I'd be interested to know if this means the material becomes locked in some forbidden decay state that prevents flourescence, if the state would decay and return to normal again over time or if the materials are denaturing in some other permanent manner due to the triplet state being available.

Know of any others dyes I could look at?
 
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  • #2
The confocal listserver just had a discussion about photobleaching. I didn't understand all of the details, but I think it had to do with excited triplet states somehow strongly interacting with (reactive) singlet oxygen species, which ultimately degrades the dye.

Quantum dots, due to a different fluorescence mechanism (excitation of confined electrons rather than excitation of molecular bound states) don't photobleach, IIRC.

What is your application?
 
  • #3



Hi there, I have some knowledge about fluorescent dyes and their properties. It is true that perylene based dyes have high quantum yields and low photobleaching rates, making them a popular choice for fluorescent labeling in biological imaging. Quantum dots also have similar advantages, with the added benefit of being able to emit a range of colors depending on their size.

As for the photobleaching mechanism, it is a complex process that involves the dye or quantum dot being excited by light and then releasing that energy in the form of heat or light. This repeated excitation can cause damage to the dye or dot, leading to a decrease in fluorescence over time. The photoxidation factor you mentioned is one of the main causes of photobleaching, but there are also other factors such as photodegradation and photobleaching byproducts.

To address your question about the triplet state, it is indeed a temporary state that can lead to photobleaching. The excited dye or dot can undergo intersystem crossing to form a triplet state, which is a long-lived state that does not emit fluorescence. This can lead to a temporary decrease in fluorescence until the triplet state decays and the dye or dot returns to its ground state.

In terms of other dyes to consider, there are many options available with different properties and applications. Some popular choices include rhodamine, fluorescein, and cyanine dyes. It ultimately depends on your specific needs and the type of experiment or imaging you are conducting.

I hope this information was helpful and gave you a better understanding of fluorescent dyes and their photobleaching mechanisms. Best of luck in your search for the perfect dye!
 

Related to Anyone know about flourescent dyes?

1. What are fluorescent dyes?

Fluorescent dyes are molecules that absorb light at one wavelength and emit light at a longer wavelength. They are widely used in scientific research and industries such as bioimaging, materials science, and forensics.

2. How do fluorescent dyes work?

Fluorescent dyes work by absorbing light at a specific wavelength and exciting electrons in the molecule to a higher energy state. When these electrons return to their ground state, they emit light at a longer wavelength, which gives off the characteristic fluorescence.

3. What are some common types of fluorescent dyes?

Some common types of fluorescent dyes include organic dyes such as fluorescein and rhodamine, and inorganic dyes such as quantum dots and lanthanide complexes. Each type has its own unique properties and applications in different fields.

4. How are fluorescent dyes used in scientific research?

Fluorescent dyes are used in a wide range of scientific research, from tracking cellular processes and protein interactions to studying the behavior of materials. They can be attached to biomolecules or incorporated into materials to provide a visual marker for specific processes.

5. Are fluorescent dyes safe to use?

In general, fluorescent dyes are considered safe to use in scientific research and industry. However, some dyes may have specific safety precautions or require special handling due to their chemical properties. It is important to always follow proper safety protocols when working with any type of chemical, including fluorescent dyes.

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