Air-stable superparamagnetic metal nanoparticles entrapped in graphene oxide matrix

0466384 - ÚPT 2017 RIV GB eng J - Journal Article
Tuček, J. - Sofer, Z. - Bouša, D. - Pumera, M. - Holá, K. - Malá, Aneta - Poláková, K. - Havrdová, M. - Čépe, K. - Tomanec, O. - Zbořil, R.
Air-stable superparamagnetic metal nanoparticles entrapped in graphene oxide matrix.
Nature Communications. Roč. 7, SEP 16 (2016), 12879:1-11, č. článku 12879. E-ISSN 2041-1723
R&D Projects: GA MŠMT(CZ) LO1212
Institutional support: RVO:68081731
Keywords : magnetic nanoparticles * biomedical applications * iron(iii) oxide * functionalization * mri * delivery * design
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 12.124, year: 2016
http://www.nature.com/articles/ncomms12879

Superparamagnetism is a phenomenon caused by quantum effects in magnetic nanomaterials. Zero-valent metals with diameters below 5 nm have been suggested as superior alternatives to superparamagnetic metal oxides, having greater superspin magnitudes and lower levels of magnetic disorder. However, synthesis of such nanometals has been hindered by their chemical instability. Here we present a method for preparing air-stable superparamagnetic iron nanoparticles trapped between thermally reduced graphene oxide nanosheets and exhibiting ring-like or core-shell morphologies depending on iron concentration. Importantly, these hybrids show superparamagnetism at room temperature and retain it even at 5 K. The corrected saturation magnetization of 185 Am-2 kg(-1) is among the highest values reported for iron-based superparamagnets. The synthetic concept is generalized exploiting functional groups of graphene oxide to stabilize and entrap cobalt, nickel and gold nanoparticles, potentially opening doors for targeted delivery, magnetic separation and imaging applications.
Permanent Link: http://hdl.handle.net/11104/0264703