Nanocrystalline Systems For Protection, Detection and Demilitarization.

Abstract : Ferritin, an ubiquitous biological iron-storage protein molecule, consists of 24 symmetrically related protein subunits forming a near-spherical hollow shell, apoferritin. The central cavity of the apoferritin shell is occupied by an iron core of ferrihydrite or 5Fe2 03. 9 H2O varying in crystallite structure (amorphous or crystalline) depending on the source of the ferritin which is widely distributed in nature (e.g., mammalian spleen, liver, heart or bacterial, plant or fungal ferritin.) Through our experimentation it has been shown not only that the iron (III) core can be photochemically reduced (Fe (II)) in presence of electron donors, but likewise that organic substrates such as oxalate and tartrate can be photo-oxidized, the ferrihydrite core acting as a catalyst, with the concomitant reduction of O2. Laser photolysis studies confirmed the reduction of cytochrome C and viologens photosensitized by ferritin via band-gap excitation. jg p2