Patent ID: 7122133

Claim:
A method of producing a stabilized dispersion of metal fine particles in an aqueous solution of R-PEG-SX comprising, fine particles of metal which is obtained by reducing at least one metallic acid or salt thereof selected from the group consisting of haloauric acid, haloplatinic acid, silver nitrate and halorhodic acid by a reducing agent, wherein, R is a functional group selected from the group consisting of acetal, aldehyde, hydroxyl group, amino group, carboxyl group, active ester group, azide group, biotin group, monosaccharide, oligosaccharide, amino acid, nucleic acid, allyl group, vinyl benzyl group, methacryloyl group and acryloyl group, PEG is polyethylene glycol having an average molecular weight of 300 to 20,000, X is H or pyridylthio group, and said fine particles load a polymer having PEG unit possessing above mentioned functional group on the surface.