Open AccessProcess mediated by gold nanoparticles encapsulated in polymeric gels evidenced by EPR spectroscopy
Author(s) -
Iulia Matei,
Marioara Bem,
Anca Ruxandra Leontieș,
Cristina RĂDUŢIU,
Elena Irina Popescu,
Sorin Mocanu,
Florenta Savonea,
Rodica Baratoiu,
Gabriela Ioniţă
Publication year - 2021
Publication title -
revue roumaine de chimie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.135
H-Index - 21
ISSN - 0035-3930
DOI - 10.33224/rrch.2021.66.3.10
Subject(s) - colloidal gold , moiety , reducing agent , electron paramagnetic resonance , chemistry , photochemistry , covalent bond , oxidizing agent , ethylene glycol , nanoparticle , redox , combinatorial chemistry , materials science , organic chemistry , nanotechnology , physics , nuclear magnetic resonance
Gold (Au0) nanoparticles (AuNPs) have been investigated for decades as selective catalysts for a series of reactions including alcohol oxidation, alkene hydrogenation and nucleophilic addition to C-C multiple bonds. In this study, the reduction/oxidation processes mediated by AuNPs embedded within a polymeric hydrogel have been tested. In particular, we monitored two processes: i) the reduction of 4-nitrophenol and ii) the reduction of a TEMPO moiety covalently linked to a fluorescent moiety, in the presence of AuNPs/hydrogel. The hybrid AuNPs/hydrogel material was obtained by reduction of a gold salt within the cross-linked poly(ethylene glycol)/β-cyclodextrin gel following a procedure previously reported. We found that this material is suitable for cyclic reduction of 4-nitrophenol as the material is not structurally modified after the reduction process. The electron paramagnetic resonance (EPR) signal of the TEMPO moiety decreases in the first instance, due to reduction by AuNPs, and slightly increases in time, proving the oxidizing property of AuNPs embedded in hydrogel.