This article presents the synthesis and
characterization of biocompatible superparamagnetic
iron oxide nanoparticles (SPIONs) coated with ultrathin
layer of anionic derivative of chitosan. The water-based
fabrication involved a two-step procedure. In the first
step, the nanoparticles were obtained by co-precipita-
tion of ferrous and ferric aqueous salt solutions with
ammonia in the presence of cationic derivative of
chitosan. In the second step, such prepared materials
were subjected to adsorption of oppositely charged
chitosan derivative which resulted in the preparation of
negatively charged SPIONs. They were found to
develop highly stable dispersion in water. The core size of the nanocoated SPIONs, determined using transmis-
sion electron microscopy, was measured to be slightly
above 10 nm. The coated nanoparticles form aggregates
with majority of them having hydrodynamic diameter
below 100 nm, as measured by dynamic light scattering.
Their composition and properties were studied using
FTIR and thermogravimetric analyses. They exhibit
magnetic properties typical for superparamagnetic
material with a high saturation magnetization value of
123
±
12 emu g
-
1
Fe. Very high value of the measured
r
2
relaxivity, 369
±
3mM
-
1
s
-
1
, is conducive for the
potential application of the obtained SPIONs as prom-
ising contrast agents in magnetic resonance imaging.
wydział: instytut / zakład / katedra:
Wydział Chemii : Zakład Chemii Fizycznej i Elektrochemii