Iron nanoparticles for plant nutrition: Synthesis, transformation, and utilization by the roots of Cucumis sativus

Nanotechnology has been evolving in the past decades as an alternative to conventional fertilizers. Ferrihydrite nanoparticles that model the available Fe pool of soils are proposed to be used to recover Fe deficiency of plants. Nevertheless, ferrihydrite aqueous suspensions are known to undergo slow transformation to a mixture of goethite and hematite, which may influence its biological availability. Several nanocolloid suspensions differing in the surfactant type were prepared for plant treatment and fully characterized by transmission electron microscopy and 57 Fe Mössbauer spectroscopy supported by magnetic measurements. The rate of transformation and the final mineral composition were revealed for all the applied surfactants. Nanomaterials at different stages of transformations were the subject of plant physiological experiments aiming at comparing the behavior and plant accessibility of the manufactured suspensions of nanoscale iron(III) oxide and oxide–hydroxide particles. Graphical abstract