I already prepared iron nanoparticles, but it oxidizes to iron oxide, so I would like to know anything about perfect stablizer to stablize my Fe nanopaticle samples. (but stablizer should be non -toxic).
For protection against oxidation of iron powders (not only "nano", but also "micro") is often used kerosene or a solution of wax (paraffin) in kerosene. In kerosene metal particles are well isolated from the atmosphere. By an application of kerosene-wax solution can produce a thin protecting wax layer on dry particles.
You can also keep the particles in ethanol at 4 degree. Natural organic materials (e.g. Suwannee River humic acid) can slow down oxidation and are generally not toxic.
As Fe get oxidize very quickly, so I totally agree with Adeyemi, keeping nanoparticles in ethanol is good but keeping it in a suitable vacuum could be a better option to keep it safe from getting oxidized...