We have successfully prepared Au nanoparticles by the sonochemically reducing Au(III) ions and immobilized them on the surface of magnetic γ-Fe2O3 nanoparticles. Au particles with average diameter of about 10 nm were homogeneously dispersed on the surface of γ-Fe2O3 (average diameter : 26 nm) without aggregation. Au nanoparticles are known to selectively adsorb the molecules having sulfur. Aiming at the uses for magnetic carriers of specific biomolecules, we employed prepared composite nanoparticles for selective separation of biomolecules and estimated their adsorption properties. The composite nanoparticles exhibited a high affinity with glutathione, a tripeptide with mercapto group, so that separation and manipulation of glutathione in aqueous solutions could be performed by applying an external magnetic field. Magnetic separations of amino acids were also investigated. Composite nanoparticles were mixed with amino acid standard solution containing 17 kinds of amino acids and their magnetic separations were carried out by applying an external magnetic field. It was found that adsorption amounts of methionine and cystine, containing internal sulfur were larger than other amino acids. The adsorbed amounts of sulfur containing amino acids increased with relative amount of Au in the composite nanoparticles.
- Composite nanoparticles
- Magnetic separation
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Computer Science Applications
- Electrical and Electronic Engineering