Naslov
Synthesis of magnetic iron oxide/Au nanostructures using the γ-irradiation method

Autori
Marić, Ivan ; Pustak, Anđela ; Gotić, Marijan ; Dražić, Goran ; Jurkin, Tanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
The Miller Online Workshop on Radiation Chemistry : Programme and Book of Abstracts / The Miller Trust Committee - , 2022, 29-29

Skup
Miller Online Workshop on Radiation Chemistry

Mjesto i datum
Online, 10.02.2022. - 12.02.2022

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
gamma-irradiation ; iron oxides ; feroxyhyte ; gold nanoparticles ; hybrid nanostructures ; HRTEM

Sažetak
Superparamagnetic iron oxide nanoparticles (MNPs) due to their unique magnetic and electrical properties have applications as biosensors, contrast agents, in drug delivery and for hyperthermia cancer treatments. For these uses, the surface of the particles should be modified with a suitable coating. Gold is one of the favored coatings because it is non-toxic, biocompatible, chemically inert, can protect MNPs from oxidation without significantly reducing magnetic properties and enables surface functionalization. It also has special optical properties. Such composite nanostructures have promising applications and advantageous properties compared to individual Au and MNPs. In this work we have used γ-irradiation as an efficient and ecologically friendly technique for the synthesis of magnetic nanoparticles. γ-irradiation has an advantage of inducing electrons and other reducing species homogeneously throughout the sample. The iron(III) chloride alkaline aqueous solutions were purged with nitrogen and γ-irradiated with addition of 2-propanol. DEAE-dextran was used as growth and stabilizing agent of MNPs in suspensions. The phase composition, stoichiometry, and morphology of MNPs were controlled by adjusting γ-irradiation dose. Irradiation with doses 10-36 kGy resulted in the formation of 4 nm spherical substoichiometric magnetite NPs, whereas at higher dose (50 kGy or more) the major phase was magnetic δ-FeOOH (feroxyhyte) in the form of nanodiscs. The reduction of Fe3+ to ferrous Fe2+ ions was quantitatively determined using the 1, 10 phenanthroline spectrophotometric method. The reduction proceeds fast in the beginning stages of irradiation (up to 30 kGy, ~65% Fe3+ reduced), slows down, and reaches 100% reduction at ~75 kGy. The reducing power of Fe2+ in irradiated suspensions was explored to synthesize composite iron oxide/Au nanostructures by the addition of aqueous solutions of HAuCl4 into the irradiated suspensions. Microstructural and morphological analysis showed that the simultaneous oxidation of Fe(OH)2 and reduction of Au3+ resulted in the formation of composite δ-FeOOH nanodiscs decorated with spherical Au nanoparticles. The density and size of Au NPs depended on the amount of added HAuCl4 aqueous solution.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA