How hollow structures form from crystalline iron-iron oxide core-shell nanoparticles in the electron beam.

Here, we report the effect of oleylamine (OLA) stabilizing molecules on the stability of iron-iron oxide core-shell nanoparticles in the electron beam. The presence of excess OLA (>50 wt%) induces the structural transformation in the highly crystalline, core-shell structures to form hollow iron oxide nanoparticles after 120 s of electron beam exposure.

One-pot synthesis of water soluble iron nanoparticles using rationally-designed peptides and ligand release.

Herein we report the rational design of new phosphopeptides for control of nucleation, growth and aggregation of water-soluble, superparamagnetic iron-iron oxide core-shell nanoparticles. The use of the designed peptides enables a one-pot synthesis that avoids utilizing unstable or toxic iron precursors, organic solvents, and the need for exchange of capping agent after synthesis of the NPs.