Is there any reason for decrease in fluorescence emission intensity of HSA,BSA when increase the concentration ?
If the concentrations are quite high, the fluorescence intensity will decrease because of the inner filter effect. This effect is due to the absorbance of the excitation light by the sample itself. For tryptophan fluorescence, one typically excites at 280 or 290 nm, which is on or near the peak of the absorbance spectrum of the protein. One way to reduce this problem is to reduce the path length of the excitation light through the sample by using a thinner cuvette. Another way is to shift the excitation wavelength away from the absorbance peak.
If the concentrations are quite high, the fluorescence intensity will decrease because of the inner filter effect. This effect is due to the absorbance of the excitation light by the sample itself. For tryptophan fluorescence, one typically excites at 280 or 290 nm, which is on or near the peak of the absorbance spectrum of the protein. One way to reduce this problem is to reduce the path length of the excitation light through the sample by using a thinner cuvette. Another way is to shift the excitation wavelength away from the absorbance peak.
Perhaps the processes of forming polymers is an explanation. Please consult some old papers and the references contained there on the concentration quenching of luminescence (jointly with Czeław Bojarski):
Article Theory of the influence of concentration on the luminescence...
Article Quenching of Photoluminescence of Solutions and Intermolecul...
Best regards, Joachim Domsta
Hi Palak Sharma you may need to have a close look at both your UV spec and fluorescence spectra. Once you plot the fluorescence intensity as a function of concentration, if you are observing a noticeable drop. Have a close look at your UV spec to see whether there is any broadening / tailing in the absorbance spectra as well. If that so, tis can be due to the aggregation caused quenching (ACQ).
- Badges
- Science topic
- Similar topics
- Philosophy
- Philosophy Of Science
- Reasoning