Are there any common lab chemicals or household stuff that produce phosphorescence?

I am aware of ZnS, CaS, Fluorescein, Erythrosin B, Vanillin Benzaldehyde, Vitamin B2, Tryptophan etc.

I just need something for sanity check on a fluorescence/phosphorecence lifetime measurement system. I am getting results with fluorescence, but not with phosphorescence.

My samples are biological plant material. With TCSPC in nano second timescale, I am getting fluorescence decay. But with micro and milli second timescale, I am getting only unifom constant counts (looking like background counts). The sanity check is to see if the instrument is able to detect phosphorescence decay from any material known to have phosphorescence, hence the question.

Counts with Nano second timescale

Counts with Nano second timescale

Counts with Milli second timescale (Red = IRF, Black = Decay)

Counts with Milli second timescale

  • 1
    $\begingroup$ There are plenty of “glow in the dark” phosphorescent things you could try, e.g., the phosphorescent stars some people put on their kid’s bedroom ceilings. You can easily find phosphorescent tape online and likewise various colors of phosphorescent paints. $\endgroup$
    – Ed V
    Jun 19 '20 at 10:45
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    $\begingroup$ It is a commercial system - Horiba DeltaPro. Excitation is with DeltaDiode Pulsed laser 375 nm. Detection is with PPD-650 (230-700 nm range). Timing electronics is DeltaHub-HT (25 ps to 1s lifetimes). Using a sample holder with front face orientation at an off-45 degree angle. In addition there is a long pass filter with 395 nm cut-on to negate scatter. $\endgroup$
    – Crops
    Jun 19 '20 at 12:14
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    $\begingroup$ Thanks, very nice system from what you say. So it is puzzling that you are “not getting results” with phosphorescence. The list of chemicals you gave does not suggest room temperature phosphorescence will be observed with them, particularly if oxygen, even at very low concentration, is present. Freeze-pump-thaw deoxygenation might do the trick (this is standard practice), but I would personally just use a phosphorescent tape or sheet. $\endgroup$
    – Ed V
    Jun 19 '20 at 12:24
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    $\begingroup$ Phosphorescence in organic materials is hard to measure unless the solvent has had all the oxygen removed as this is a very efficient quencher, as are heavy atoms/ions such as iodide. Thus you need to freeze-pump-thaw on a vacuum line with liq Nitrogen, or purge with O2 free nitrogen or argon and seal the cell completely, vacuum taps etc. Fluorescence lifetimes are best measured by time correlated single photon counting on nanosecond timescale (many commercial systems exist), phosphorescence is very slow (microsecond and longer) that a laser and scope are easily fast enough. $\endgroup$
    – porphyrin
    Jun 19 '20 at 13:51
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    $\begingroup$ @Crops, I copied your main question from comments to the main question, otherwise random people will keep down voting an otherwise useful query. $\endgroup$
    – M. Farooq
    Jun 19 '20 at 14:18

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