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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Autores principales:	Lagorio, María Gabriela, San Roman, Enrique Arnoldo
Publicado:	2001
Materias:	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
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v3_n8_p1524_Lagorio http://hdl.handle.net/20.500.12110/paper_14639076_v3_n8_p1524_Lagorio
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_14639076_v3_n8_p1524_Lagorio
record_format	dspace
spelling	paper:paper_14639076_v3_n8_p1524_Lagorio2023-06-08T16:16:35Z Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose Lagorio, María Gabriela San Roman, Enrique Arnoldo 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. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v3_n8_p1524_Lagorio 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, María Gabriela San Roman, Enrique Arnoldo 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.
author	Lagorio, María Gabriela San Roman, Enrique Arnoldo
author_facet	Lagorio, María Gabriela San Roman, Enrique Arnoldo
author_sort	Lagorio, María Gabriela
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
publishDate	2001
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v3_n8_p1524_Lagorio http://hdl.handle.net/20.500.12110/paper_14639076_v3_n8_p1524_Lagorio
work_keys_str_mv	AT lagoriomariagabriela photophysicsonsurfacesabsorptionandluminescencepropertiesofpheophorbideaoncellulose AT sanromanenriquearnoldo photophysicsonsurfacesabsorptionandluminescencepropertiesofpheophorbideaoncellulose
_version_	1768542856637579264

Photophysics on surfaces: Absorption and luminescence properties of pheophorbide-a on cellulose

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