Surface-Mediated Production of Complexed â¢OH Radicals and FeO Species as a Mechanism for Iron Oxide Peroxidase-Like Nanozymes.
Small
; 18(50): e2204372, 2022 12.
Article
em En
| MEDLINE
| ID: mdl-36316230
ABSTRACT
Fe3 O4 nanoparticles (NPs) with intrinsic peroxidase-like properties have attracted significant interest, although limited information is available on the definite catalytic mechanism. Here, it is shown that both complexed hydroxyl radicals (â¢OH) and high-valent FeO species are attributed primarily to the peroxidase-like catalytic activity of Fe3 O4 NPs under acid conditions rather than only being caused by free â¢OH radicals generated through the iron-driven Fenton/Haber-Weiss reactions as previously thought. The low energy barrier of OO bond dissociation of H2 O2 /â¢OOH (0.14 eV) and the high oxidation activity of surface FeO (0 eV) due to the reduced state of Fe on the surface of Fe3 O4 NPs thermodynamically favor both the â¢OH and FeO pathways. By contrast, high-valent FeO species are the key intermediates in the catalytic cycles of natural peroxidase enzymes. Moreover, it is demonstrated that the enzyme-like activity of Fe3 O4 NPs can be rationally regulated by modulating the size, surface structure, and valence of active metal atoms in the light of this newly proposed nanozyme catalytic mechanism.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos Férricos
/
Peroxidase
Idioma:
En
Revista:
Small
Assunto da revista:
ENGENHARIA BIOMEDICA
Ano de publicação:
2022
Tipo de documento:
Article