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1 vote
2 answers
2k views

What makes a species "fluorescence quencher"?

I just came across an article where they said that sodium fluoride is not quencher (in the context of fluorescence). Why is NaF not a quencher but NaBr is one?
5 votes
3 answers
354 views

Excited states and emission lifetimes

I have some doubts about the nomenclature of the lifetimes. Are singlet and fluorescence lifetimes the same? As well as the triplet and phosphorescence lifetimes? Also, can the triplet/phosphorescence ...
1 vote
0 answers
83 views

Spectroscopic methods for quantifying peptides/proteins with or without Tryptophan or Tyrosine content

I have several peptides (20-50 amino acids long) which I want to quantify the solubility/concentration in a solvent at certain temperature and pH. These peptides may or may not contain Tryptophan or ...
1 vote
1 answer
162 views

Why does isolated chlorophyl emits red light?

If we observe isolated chlorophyl solution with UV light, chlorophyl is seen as red. Explanation suggests that when a specific atom of chlorophyl absorbs UV light, the atom gets excited and in a short ...
3 votes
0 answers
99 views

How can I set up and process my excitation-emission matrices properly?

I'm running EEMS on some water samples on a Horiba Fluoromax 4 spectrofluorometer. Method below. $\pu{240-580nm}$ emission, $\pu{5nm}$ interval, $\pu{1nm}$ width. $\pu{240-480nm}$ excitation, $\pu{...
4 votes
1 answer
2k views

Absorption and emission at same wavelength?

Is it possible for a molecule to absorb and emit at the same wavelength? What is the reason behind it? I’m working on charged tin porphyrins and got the excitation and emission (fluorescence) ...
1 vote
2 answers
480 views

Implications of the excitation spectra

The fluorescence excitation spectra show the change in fluorescence intensity as a function of the wavelength of the excitation light. I'm interested in the certain physical implications of the above. ...
2 votes
1 answer
580 views

Is the XRF spectroscopy equally sensitive for every element?

I am curious whether or not every element can be equally well detected by using X-Ray-fluorescence-spectroscopy. Might there be any contitions or circumstances that make it hard/impossible to detect a ...
0 votes
0 answers
73 views

Does something like a fluorescent foil or a fluorescent film exist?

During my experiments I want the emitted laser beams to come back with a different wavelength than the original wavelength using a fluorescent foil or fluorescent film. The laser I'm currently using ...
1 vote
1 answer
1k views

What is the relationship between emission and fluorescence?

A molecule exposed to a photon with some energy is put into an excited state, and emits a photon of some energy when it returns to ground state. The photon that provided the energy for excitation ...
1 vote
0 answers
39 views

Does the laser side of laser fluorescence spectroscopy have to be so complicated?

I understand the working principle behind zapping some gas and looking at spectral emissions, and I can see why photodetection is so difficult. But I thought that pointing a laser into a vacuum ...
1 vote
3 answers
1k views

What are the requirements for FRET?

I have a question about fluorescence resonance energy transfer (FRET), and the requirements needed for this technique. Q: Which of the following need to be met for FRET? A) Strong overlap between ...