Fluorescence compounds have a special characteristics properties. Among them fluorescence lifetime is one belongs to the excited state behavior of fluorescent molecule. How one can directly determine the fluorescence lifetime of particular compound by using the decay curve obtained from TCSPC method ? Full length half width is one prior method to use frequently by researchers. Is there any other simple method to calculate the direct value by observing only decay curves.?
Dear Prasad,
May be my answer is no longer useful for you, but it may be useful for the other researchers. So, It is assumed the photoexcitation produces an excess of excited state which decays on the average after the elapsing of their lifetime. This process is relaxation process and produces photon flux phi(t)which decay exponentially with time.
So, one normally assumes
phi(t)=phi(0) exp-t/ Tau
Tau is calculated from this relation
Accordingly one can plot Ln (phi/phi(0)) versus t which is a straight line. From the slope of the straight line one can get Tau, The slope is I/Tau.
Best wishes
Please see these references.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.147.7445&rep=rep1&type=pdf
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4070492/
Other than time, the laser intensity and solvent used can affect the half-life of fluorescence. Therefore, it could be a good idea to have an internal control of known standard (e.g. fluorescein, in the case of small molecule) to give a feel of how an analyte molecule compares with the standard.
See also this thread:
https://www.researchgate.net/post/Can_anybody_help_with_fluorescence_decay_profile_of_fluorescein_dianion
Good luck
Thank you Peter Sir,
Actaully, the method given by you is related to the same method as mentioned FWHM. What is mean by Gravicentre ? Is the fl time of sample is cancelled with the IRF.............
I have direct value from the decay curves evaluation on multiexponential fitting on TCSPC. But for the better understanding of the subject i eager to know that how one can calculate FL time by directly observing decay curves
When I worked on this many years ago, I developed an interative reconvolution method to determine: 1) the number of constituent decay times and 2) the actual intensity contribution for each component. Depending on how close the individual times are, this method could discern up to 5 separate components. Have a look at my dissertation, the instrument section:
Article Time-correlated single photon studies of hydrogenated amorph...
Thank you Peter sir, Wong sir and Pleil sir for valuable guidance on same. But still i am little bit confused. I will contact you whenever i detect a problem to calculate it.
Dear Prasad,
May be my answer is no longer useful for you, but it may be useful for the other researchers. So, It is assumed the photoexcitation produces an excess of excited state which decays on the average after the elapsing of their lifetime. This process is relaxation process and produces photon flux phi(t)which decay exponentially with time.
So, one normally assumes
phi(t)=phi(0) exp-t/ Tau
Tau is calculated from this relation
Accordingly one can plot Ln (phi/phi(0)) versus t which is a straight line. From the slope of the straight line one can get Tau, The slope is I/Tau.
Best wishes
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