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Magnetic Au Nanoparticles on Archaeal S-Layer Ghosts as Templates

Sonja Selenska-Pobel ; Institute of Radiochemistry, Helmholz- Zentrum Dresden-Rossendorf, German
Thomas Reitz ; Institute of Radiochemistry, Helmholz- Zentrum Dresden-Rossendorf, German
Rico Schöneman ; Dresden High Magnetic Field Laboratory, Helmholz- Zentrum Dresden-Rossendorf, German
Thomas Herrmansdörfer ; Dresden High Magnetic Field Laboratory, Helmholz- Zentrum Dresden-Rossendorf, German
Mohamed Merroun ; Department of Microbiology, University of Granada, Spai
Andrea Geißler ; Institute of Radiochemistry, Helmholz- Zentrum Dresden-Rossendorf, German
Juan Bartolomé ; ICMA, Departamento de Física de la Materia Condensada, CSIC – Universidad of Zaragoza, Spai
Fernando Bartolomé ; ICMA, Departamento de Física de la Materia Condensada, CSIC – Universidad of Zaragoza, Spai
Luis Miguel García ; ICMA, Departamento de Física de la Materia Condensada, CSIC – Universidad of Zaragoza, Spai
Fabrice Wilhelm ; European Synchrotron Radiation Facility (ESRF), France
Andrei Rogalev ; European Synchrotron Radiation Facility (ESRF), France

Sažetak

Cell‐ghosts representing empty cells of the
archaeon Sulfolobus acidocaldarius, consisting only of their
highly ordered and unusually stable outermost
proteinaceous surface layer (S‐layer), were used as
templates for Au nanoparticles fabrication. The properties
of these archaeal Au nanoparticles differ significantly
from those produced earlier by us onto bacterial S‐layer
sheets. The archaeal Au nanoparticles, with a size of
about 2.5 nm, consist exclusively of metallic Au(0), while
those produced on the bacterial S‐layer had a size of
about 4 nm and represented a mixture of Au(0) and
Au(III) in the ratio of 40 to 60 %.  
The most impressive feature of the archaeal Au
nanoparticles is that they are strongly paramagnetic, in
contrast to the bacterial ones and also to bulk gold.
SQUID magnetometry and XMCD measurements
demonstrated that the archaeal Au nanoparticles possess
a rather large magnetic moment of about 0.1B/atom. HR‐
TEM‐EDX analysis revealed that the archaeal Au
nanoparticles are linked to the sulfur atoms of the thiol
groups of the amino acid cysteine, characteristic only for
archaeal S‐layers. This is the first study demonstrating the
formation of such unusually strong magnetic Au
nanoparticles on a non‐modified archaeal S‐layer

Ključne riječi

Magnetic Au nanoparticles; archaeal S‐layer; High Resolution Transmission Electron Microscopy  (HR‐ TEM; X‐ray Magnetic Circular Dichroism (XMCD)

Hrčak ID:

72508

URI

https://hrcak.srce.hr/72508

Datum izdavanja:

15.9.2011.

Posjeta: 1.910 *