Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose
Solid samples of Pheophorbide-a adsorbed on microcrystalline cellulose were prepared with a wide range of dye concentrations (7.1 ± 10-9 to 8.9 ± 10-6 mol (g cellulose-1) and studied by diffuse reflectance and steady-state and time-resolved fluorescence spectroscopy in the solid state. Absorption sp...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_14639076_v3_n8_p1524_Lagorio |
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todo:paper_14639076_v3_n8_p1524_Lagorio2023-10-03T16:16:59Z Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose Lagorio, M.G. San Román, E. Zeug, A. Zimmermann, J. Röder, B. cellulose chlorophyll a dye pheophorbide a unclassified drug absorption spectroscopy article chemoluminescence concentration (parameters) diffuse reflectance spectroscopy energy transfer flame photometry fluorescence spectroscopy solid state steady state synthesis Solid samples of Pheophorbide-a adsorbed on microcrystalline cellulose were prepared with a wide range of dye concentrations (7.1 ± 10-9 to 8.9 ± 10-6 mol (g cellulose-1) and studied by diffuse reflectance and steady-state and time-resolved fluorescence spectroscopy in the solid state. Absorption spectra obtained by means of reflectance spectroscopy were compared with those found in different environments and carrier systems. No aggregation may be inferred from the spectroscopic data. Changes in the fluorescence spectra with increasing dye concentration are attributed to: (a) reabsorption of luminescence and re-emission and (b) interaction between the excited dye molecule and ground state neighboring molecules. The first e ect accounts for the observed differences in emission spectra for thin and thick layers of a given sample. Emission decays are non-exponential even at low dye concentrations. A Förster energy transfer mechanism leading to energy trapping by molecules of the same type as the excited dye is proposed. Fil:Lagorio, M.G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:San Román, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14639076_v3_n8_p1524_Lagorio |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
cellulose chlorophyll a dye pheophorbide a unclassified drug absorption spectroscopy article chemoluminescence concentration (parameters) diffuse reflectance spectroscopy energy transfer flame photometry fluorescence spectroscopy solid state steady state synthesis |
| spellingShingle |
cellulose chlorophyll a dye pheophorbide a unclassified drug absorption spectroscopy article chemoluminescence concentration (parameters) diffuse reflectance spectroscopy energy transfer flame photometry fluorescence spectroscopy solid state steady state synthesis Lagorio, M.G. San Román, E. Zeug, A. Zimmermann, J. Röder, B. Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose |
| topic_facet |
cellulose chlorophyll a dye pheophorbide a unclassified drug absorption spectroscopy article chemoluminescence concentration (parameters) diffuse reflectance spectroscopy energy transfer flame photometry fluorescence spectroscopy solid state steady state synthesis |
| description |
Solid samples of Pheophorbide-a adsorbed on microcrystalline cellulose were prepared with a wide range of dye concentrations (7.1 ± 10-9 to 8.9 ± 10-6 mol (g cellulose-1) and studied by diffuse reflectance and steady-state and time-resolved fluorescence spectroscopy in the solid state. Absorption spectra obtained by means of reflectance spectroscopy were compared with those found in different environments and carrier systems. No aggregation may be inferred from the spectroscopic data. Changes in the fluorescence spectra with increasing dye concentration are attributed to: (a) reabsorption of luminescence and re-emission and (b) interaction between the excited dye molecule and ground state neighboring molecules. The first e ect accounts for the observed differences in emission spectra for thin and thick layers of a given sample. Emission decays are non-exponential even at low dye concentrations. A Förster energy transfer mechanism leading to energy trapping by molecules of the same type as the excited dye is proposed. |
| format |
JOUR |
| author |
Lagorio, M.G. San Román, E. Zeug, A. Zimmermann, J. Röder, B. |
| author_facet |
Lagorio, M.G. San Román, E. Zeug, A. Zimmermann, J. Röder, B. |
| author_sort |
Lagorio, M.G. |
| title |
Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose |
| title_short |
Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose |
| title_full |
Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose |
| title_fullStr |
Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose |
| title_full_unstemmed |
Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose |
| title_sort |
photophysics on surfaces: absorption and luminescence properties of pheophorbide-a on cellulose |
| url |
http://hdl.handle.net/20.500.12110/paper_14639076_v3_n8_p1524_Lagorio |
| work_keys_str_mv |
AT lagoriomg photophysicsonsurfacesabsorptionandluminescencepropertiesofpheophorbideaoncellulose AT sanromane photophysicsonsurfacesabsorptionandluminescencepropertiesofpheophorbideaoncellulose AT zeuga photophysicsonsurfacesabsorptionandluminescencepropertiesofpheophorbideaoncellulose AT zimmermannj photophysicsonsurfacesabsorptionandluminescencepropertiesofpheophorbideaoncellulose AT roderb photophysicsonsurfacesabsorptionandluminescencepropertiesofpheophorbideaoncellulose |
| _version_ |
1807321557104590848 |