Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts

Effects of gold nanoparticles (average diameter: 10-14 nm) on leaves and chloroplasts have been studied. Gold nanoparticles (AuNPs) quenched significantly chlorophyll fluorescence when introduced both in intact leaves and isolated chloroplasts. Additionally, the fluorescence spectra corrected for li...

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Autores principales: Torres, R., Diz, V.E., Lagorio, M.G.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_1474905X_v17_n4_p505_Torres
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spelling todo:paper_1474905X_v17_n4_p505_Torres2023-10-03T16:18:21Z Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts Torres, R. Diz, V.E. Lagorio, M.G. Effects of gold nanoparticles (average diameter: 10-14 nm) on leaves and chloroplasts have been studied. Gold nanoparticles (AuNPs) quenched significantly chlorophyll fluorescence when introduced both in intact leaves and isolated chloroplasts. Additionally, the fluorescence spectra corrected for light re-absorption processes showed a net decrease in the fluorescence ratio calculated as the quotient between the maximum fluorescence at 680 and 735 nm. This fact gave evidence for a reduction in the fluorescence emission of the PSII relative to that of the PSI. Strikingly, the photosynthetic parameters derived from the analysis of the slow phase of Kautsky's kinetics, the rate of oxygen evolution and the rate of photo-reduction of 2,6-dichlorophenolindophenol were increased in the presence of AuNPs indicating an apparent greater photosynthetic capacity. The observed results were consistent with an electron transfer process from the excited PSII, which was thermodynamically possible, and which competed with both the electron transport process that initiated photosynthesis and the deactivation of the excited PSII by fluorescence emission. Additionally, it is here explained, in terms of a completely rational kinetic scheme and their corresponding algebraic expressions, why the photosynthetic parameters and the variable and non-variable fluorescence of chlorophyll are modified in a photosynthetic tissue containing gold nanoparticles. © 2018 The Royal Society of Chemistry and Owner Societies. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_1474905X_v17_n4_p505_Torres
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description Effects of gold nanoparticles (average diameter: 10-14 nm) on leaves and chloroplasts have been studied. Gold nanoparticles (AuNPs) quenched significantly chlorophyll fluorescence when introduced both in intact leaves and isolated chloroplasts. Additionally, the fluorescence spectra corrected for light re-absorption processes showed a net decrease in the fluorescence ratio calculated as the quotient between the maximum fluorescence at 680 and 735 nm. This fact gave evidence for a reduction in the fluorescence emission of the PSII relative to that of the PSI. Strikingly, the photosynthetic parameters derived from the analysis of the slow phase of Kautsky's kinetics, the rate of oxygen evolution and the rate of photo-reduction of 2,6-dichlorophenolindophenol were increased in the presence of AuNPs indicating an apparent greater photosynthetic capacity. The observed results were consistent with an electron transfer process from the excited PSII, which was thermodynamically possible, and which competed with both the electron transport process that initiated photosynthesis and the deactivation of the excited PSII by fluorescence emission. Additionally, it is here explained, in terms of a completely rational kinetic scheme and their corresponding algebraic expressions, why the photosynthetic parameters and the variable and non-variable fluorescence of chlorophyll are modified in a photosynthetic tissue containing gold nanoparticles. © 2018 The Royal Society of Chemistry and Owner Societies.
format JOUR
author Torres, R.
Diz, V.E.
Lagorio, M.G.
spellingShingle Torres, R.
Diz, V.E.
Lagorio, M.G.
Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts
author_facet Torres, R.
Diz, V.E.
Lagorio, M.G.
author_sort Torres, R.
title Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts
title_short Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts
title_full Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts
title_fullStr Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts
title_full_unstemmed Effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts
title_sort effects of gold nanoparticles on the photophysical and photosynthetic parameters of leaves and chloroplasts
url http://hdl.handle.net/20.500.12110/paper_1474905X_v17_n4_p505_Torres
work_keys_str_mv AT torresr effectsofgoldnanoparticlesonthephotophysicalandphotosyntheticparametersofleavesandchloroplasts
AT dizve effectsofgoldnanoparticlesonthephotophysicalandphotosyntheticparametersofleavesandchloroplasts
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