Oxygen reduction on iron-melanin granular surfaces

We report the catalytic activity of iron-eumelanin granular deposits supported on graphite for the oxygen reduction in neutral and alkaline solutions. These deposits contain quinone groups and iron-melanin complexes as revealed by XPS, XANES, EXAFS, and IR spectroscopy. Voltammetric data show that t...

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Publicado: 2009
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v113_n39_p17097_Orive
http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive
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spelling paper:paper_19327447_v113_n39_p17097_Orive2023-06-08T16:31:28Z Oxygen reduction on iron-melanin granular surfaces Alkaline solutions Catalytic activity Dopaminergic neurons Electrocatalytic activity Eumelanins EXAFS Four electrons Granular deposits Hydroxyl species IR spectroscopy Lipid peroxidation Neurodegeneration Oxygen Reduction Quinone groups Voltammetric data XANES XPS Catalyst activity Deposits Electrocatalysis Electrochemical sensors Electrolytic reduction Graphite Iron compounds Neurons Oxygen Physical chemistry Iron deposits We report the catalytic activity of iron-eumelanin granular deposits supported on graphite for the oxygen reduction in neutral and alkaline solutions. These deposits contain quinone groups and iron-melanin complexes as revealed by XPS, XANES, EXAFS, and IR spectroscopy. Voltammetric data show that the iron-eumelanin system exhibits higher electrocatalytic activity than quinone/hydroquinone films (Q/QH) on the same substrate. In contrast to Q/QH deposits, the iron-containing eumelanin system is able to reduce oxygen with transfer of four electrons, thus allowing the formation of reactive hydroxyl species. Our results can explain the physical chemistry basis of the oxygen-radical induced lipid peroxidation and consequent neurodegeneration of the melanin-containing dopaminergic neurons observed by several authors. © 2009 American Chemical Society. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v113_n39_p17097_Orive http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Alkaline solutions
Catalytic activity
Dopaminergic neurons
Electrocatalytic activity
Eumelanins
EXAFS
Four electrons
Granular deposits
Hydroxyl species
IR spectroscopy
Lipid peroxidation
Neurodegeneration
Oxygen Reduction
Quinone groups
Voltammetric data
XANES
XPS
Catalyst activity
Deposits
Electrocatalysis
Electrochemical sensors
Electrolytic reduction
Graphite
Iron compounds
Neurons
Oxygen
Physical chemistry
Iron deposits
spellingShingle Alkaline solutions
Catalytic activity
Dopaminergic neurons
Electrocatalytic activity
Eumelanins
EXAFS
Four electrons
Granular deposits
Hydroxyl species
IR spectroscopy
Lipid peroxidation
Neurodegeneration
Oxygen Reduction
Quinone groups
Voltammetric data
XANES
XPS
Catalyst activity
Deposits
Electrocatalysis
Electrochemical sensors
Electrolytic reduction
Graphite
Iron compounds
Neurons
Oxygen
Physical chemistry
Iron deposits
Oxygen reduction on iron-melanin granular surfaces
topic_facet Alkaline solutions
Catalytic activity
Dopaminergic neurons
Electrocatalytic activity
Eumelanins
EXAFS
Four electrons
Granular deposits
Hydroxyl species
IR spectroscopy
Lipid peroxidation
Neurodegeneration
Oxygen Reduction
Quinone groups
Voltammetric data
XANES
XPS
Catalyst activity
Deposits
Electrocatalysis
Electrochemical sensors
Electrolytic reduction
Graphite
Iron compounds
Neurons
Oxygen
Physical chemistry
Iron deposits
description We report the catalytic activity of iron-eumelanin granular deposits supported on graphite for the oxygen reduction in neutral and alkaline solutions. These deposits contain quinone groups and iron-melanin complexes as revealed by XPS, XANES, EXAFS, and IR spectroscopy. Voltammetric data show that the iron-eumelanin system exhibits higher electrocatalytic activity than quinone/hydroquinone films (Q/QH) on the same substrate. In contrast to Q/QH deposits, the iron-containing eumelanin system is able to reduce oxygen with transfer of four electrons, thus allowing the formation of reactive hydroxyl species. Our results can explain the physical chemistry basis of the oxygen-radical induced lipid peroxidation and consequent neurodegeneration of the melanin-containing dopaminergic neurons observed by several authors. © 2009 American Chemical Society.
title Oxygen reduction on iron-melanin granular surfaces
title_short Oxygen reduction on iron-melanin granular surfaces
title_full Oxygen reduction on iron-melanin granular surfaces
title_fullStr Oxygen reduction on iron-melanin granular surfaces
title_full_unstemmed Oxygen reduction on iron-melanin granular surfaces
title_sort oxygen reduction on iron-melanin granular surfaces
publishDate 2009
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v113_n39_p17097_Orive
http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive
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