Patent ID: 7875352

Claim:
A stabilized inorganic nanoparticle obtained by bonding protective ligands to a surface of an inorganic nanoparticle having a plurality of binding sites on its surface to stabilize the inorganic nanoparticle, wherein one part of the binding sites on the surface of the inorganic nanoparticle are bonded to the protective ligand, the other part of the binding sites remain as a free sites not bonded to protective ligands, and the stabilized inorganic nanoparticle satisfies a condition that either the amount of the protective ligand bonded to the inorganic nanoparticle is a critical amount, or the condition that the form of the protective ligand-modified surface of the inorganic nanoparticle by the protective ligand is a critical modification form, wherein, when the amount of protective ligand bound to the inorganic nanoparticle is a critical amount, the critical amount is defined as one of (1) an amount between a lower limit required for stabilizing the inorganic nanoparticle and an upper limit at or below which a functional ligand is capable of bonding to the inorganic nanoparticle without interference from bound protective ligand, or (2) an amount required for bonding the protective ligand to 8% to 30% of the binding sites on the surface of the inorganic nanoparticle without hindering either the stability of the inorganic nanoparticle or the reactivity of remaining binding sites, and further wherein, when the form of the protective ligand-modified surface is a critical modification form, critical modification form is defined as (3) a form with a spatial arrangement in which the molecular skeleton of the protective ligands are arranged along a tangent to the surface of the inorganic nanoparticle, and the free sites on the surface of the inorganic nanoparticle are covered with the molecular skeleton.