TITLE:
Pyranine Fluorescence Quenching for the Characterization of Solutions
AUTHORS:
Qiuxia Wang, Kris A. Berglund
KEYWORDS:
Fluorescence Quenching, Pyranine, Solution Structure, Tryptophan
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.7 No.1,
January
22,
2016
ABSTRACT: Fluorescence
quenching of pyranine by tryptophan, phenylalanine, and nicotinic acid was
investigated by using steady state and time resolved fluorescence spectroscopy.
On a comparative basis, nicotinic acid is a very strong quencher of pyranine
fluorescence, tryptophan is a moderate quencher and phenylalanine is a weak
quencher. The strong quenching is the result of the hydrogen bonding complex
between pyranine and amine which existed in both tryptophan and nicotinic acid.
Contact complex will form between phenylalanine and pyranine which is the
reason of quenching of pyranine by phenylalanine. Associates will form in
tryptophan and phenylalanine due to the zwitterion +H3NRCOO- or/and hydrogen bond. Higher concentrations favor
the formation of aggregates in the supersaturated solution which made the
quenching curve different from unsaturated solution dramatically.