Size control for two-dimensional iron oxide nanodots derived from biological molecules.
We demonstrated the fabrication of size-controlled two-dimensional iron oxide nanodots derived from the heat treatment of ferritin molecules self-immobilized on modified silicon surfaces. Ferritin molecules were immobilized onto 3-aminopropyltrimethoxysilane (3-APMS)-modified silicon surfaces by electrostatic interactions between negatively charged amino acids of ferritin molecules and amino terminal functional groups of 3-APMS. Heat treatments were performed at 400 degrees C for 60 min to fabricate two-dimensional nanodots based on ferritin cores. XPS and FT-IR results clearly indicate that ferritin shells were composed of amino acids and 3-APMS modifiers on silicon surfaces were eliminated by heat treatment. Nanodots on substrate surfaces corresponded to iron oxides. The size of nanodots was tunable in the range of 0-5 (+/-0.75) nm by in situ reactions of iron ion chelators with ferritin molecules immobilized on substrates before heat treatment.
Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, Kumamoto 860-8555, Japan. masato@gpo.kumamoto-u.ac.jp
Masato
M
Tominaga
Manabu
M
Matsumoto
Kazuki
K
Soejima
Isao
I
Taniguchi
D000818:Animals; D002614:Chelating Agents / Q000737:chemistry; D002850:Chromatography, Gel; D005290:Ferric Compounds / Q000737:chemistry*; D005293:Ferritins / Q000737:chemistry / Q000302:isolation & purification; D006736:Horses; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013154:Spleen; D055672:Static Electricity
D002614:Chelating Agents; D005290:Ferric Compounds; C000499:ferric oxide; D005293:Ferritins