Facile synthesis of superparamagnetic iron oxide nanoparticles with tunable size: from individual nanoparticles to nanoclusters

Abstract

Superparamagnetic iron oxide nanoparticles (SPIONs) have a wide variety of biomedical applications. Synthesis of SPIONs with well-defined, tunable size in a facile way is highly desirable. In this work, a one-pot polyol method was developed for preparation of SPIONs with tunable size and high quality in the presence of poly (acrylic acid) (PAA). By adjusting the amount of PAA used, the isolated nanoparticles and nanoparticle clusters were able to be synthesised. As-synthesised nanoparticles and nanoclusters were highly stable in physiological conditions. The size of the nanoparticles was 7 ± 1 nm and that for the nanoclusters was 20 ± 2 and 32 ± 3 nm, respectively. The nanoparticles demonstrated good magnetic resonance imaging T 1 and T 2 dual contrast effects (r 1 = 12.2 mM −1 s −1 and r 2 = 47.5 mM −1 s −1), while the nanoclusters exhibited a superior T 2 contrast effect with the transverse relaxivities of 198 mM −1 s −1 (20 ± 2 nm) and 410 mM −1 s −1 (32 ± 3 nm), respectively. More importantly, both the nanoparticles and nanoclusters were highly tolerable by cells.

Stable Iron Oxide Nanoflowers with Exceptional Magnetic Heating Efficiency: Simple and Fast Polyol Synthesis

“…Following the work of Mi et al 30 showing that the addition of PAA can yield clustered IONPs, the synthesis was also performed in the presence of PAA in a range of different concentrations (0.02−0.1 M). The experimental procedure (with PAA) is shown in step 1 and 2 in Figure 6.…”

“…The influence of poly­(acrylic acid) (PAA) concentration over the magnetic and structural properties of IONPs for the coprecipitation method has previously been reported. , Mi et al showed that for the thermal decomposition of Fe­(acac) 3 in polyol, the increase of PAA concentration would contribute mostly at coating the particles, as the chance of a PAA molecule binding with multinanocrystal nuclei could be enhanced.…”