Questions tagged [fluorescence]
For questions relating to the radiation emitted by substances as a result of incident radiation.
84
questions
3
votes
0
answers
78
views
Fluorophores with high quantum yield and low lifetime
Does anyone know of any fluorophore or family of fluorophores with a relatively high fluorescence quantum yield (larger than 0.1) and a short lifetime (below hundreds of picoseconds)?
I have been ...
- 161
3
votes
0
answers
41
views
Wave Dispersive X-ray Fluoresence and Bragg's Law
Thermo Fisher website explains that "WDXRF uses crystals to disperse the fluorescence spectrum into individual wavelengths of each element, providing high resolution and low background spectra ...
user119534
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{...
- 61
3
votes
0
answers
130
views
Fluorescence Intensity and Fluorescence Quantum Yield
I plan to use ImageJ to analyze some fluorescence experiments where the pH changes. I will be using fluorescein as the indicator for the pH changes and it will be present in low concentration (like is ...
- 173
2
votes
2
answers
1k
views
Why do some molecules show non-symmetric absorption and emission bands?
I'm looking at a molecule of [Ru(bpy)3]2+ in water and the absorption and emission bands are not symmetrical. I want to know why the mirror image rule doesn't apply here. Is this because of the MLCT, ...
- 23
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 ...
- 105
2
votes
2
answers
410
views
Why does aqeous fluorescein shine when exposed to UV light?
I know that (aq) fluorescein "absorbs" UV light and releases light in the visible spectrum , but how does it do that. It is a really interesting and useful organic chemical and I just wanted to know ...
- 376
2
votes
1
answer
2k
views
Is Beer-Lambert law also valid for fluorescence and luminescence?
When I measure optical density in a microplate reader the absorbance is proportional to the concentration and the height of the liquid. Is Beer-Lambert law also valid for fluorescence and luminescence?...
- 123
2
votes
1
answer
128
views
Calculate IC50 from fluorescence kinetic
I have an assay in which a fluorescence signal is generated when the enzyme reaction progresses. The fluorescence signal increases until a maximum is reached. Than it keeps constant. The first 1 h ...
- 799
2
votes
0
answers
39
views
High voltage arc treatment leads to the appearance of fluorescent granules in soda baking. Perhaps it's the F-centers?
I have a high-voltage converter at home, consisting of a horizontal "flyback" transformer from an old tube TV, field-effect power transistors and a square-wave generator with adjustable ...
- 115
2
votes
0
answers
46
views
DNA staining agent with good absorbance at 532 nm
I need to stain some double-stranded DNA with an intercalating fluorescent dye. For imaging, I am using a microscope setup equiped with a 532 nm green laser.
What is the staining agent of choice to ...
- 201
2
votes
0
answers
58
views
What causes horizontal lines on an excitation-emission matrix in fluorometry?
I am doing excitation-emission matrices to test for CDOM, and we just got some brand new quarts cuvettes. When I hold them in front of a light, they're totally clear and clean.
I ran a sample, and in ...
- 61
2
votes
0
answers
1k
views
Data analysis in TCSPC for fluorescene decay (reconvolution with measured IRF)
I am trying to understand the data analysis of fluorescence decay counts measured by TCSPC technique, particularly with reconvolution with measured IRF.
I am able to get the fitted counts (given by ...
- 139
2
votes
0
answers
50
views
Chemical Potential in the Fluorescent Molecule
I'm reading this paper, which states that the chemical potential $\mu$ is determined by the steady-state balance of up and down transitions in a fluorescent molecule. I am happy with this ...
- 590
2
votes
0
answers
81
views
What's causing this dip in the FCS curve?
This is a fluorescence correlation spectroscopy measurement of light harvesting complexes. What could be causing the dip at 100 microseconds?
Edit:
The same thing was observed using fluorescence ...
- 93