| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 28642 | Journal of Photochemistry and Photobiology A: Chemistry | 2011 | 7 Pages |
The fluorescence and phosphorescence behavior of the fluorone dyes disodium fluorescein (uranine), 4,5-dibromofluorescein, eosin Y, erythrosine B, and rose bengal in biofilms of chitosan, gelatin, and starch was studied in the temperature range from 293 K to 12 K. Luminescence quantum yields, fluorescence quantum yields, and triplet quantum yields were determined. The fluorescence quantum yield generally increased with lowering the temperature at a high level of absolute quantum yield, while the phosphorescence quantum yield increased with decreasing temperature at a low level of absolute quantum yield. The strongest phosphorescence was found for erythrosine B in starch where the phosphorescence quantum yield increased from 6% at 293 K to 25% at 12 K. The temperature dependent luminescence behavior is discussed considering radiative and non-radiative transitions in a spectroscopic-state potential energy surface scheme.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Fluorescence quantum distributions of fluorones in temperature range 293–12 K were determined. ► Phosphorescence quantum yields of fluorones in temperature range 293–12 K were determined. ► Spectroscopic-state potential energy model was used for description of luminescence behavior. ► Fluorescence increased with decreasing temperature at high absolute quantum yield level. ► Phosphorescence increased with decreasing temperature at low absolute quantum yield level.
