MAGNETIC PARTICLE FOR ANTIBODY BINDING AND MANUFACTURING METHOD THEREFOR

To provide a magnetic particle which has superior acid resistance that leads to less elution of iron even when treated with an acidic aqueous solution, exhibits good dispersibility to water, less non-specific absorption, and large specific particle surface area that allows for carrying a large amount of physiologically active substances, and is capable of enhancing immunodiagnostic sensitivity.SOLUTION: A magnetic particle for antibody binding is provided, comprising a core particle 1, a first coating layer formed on a surface of the core particle, and a second coating layer formed on a surface of the first coating layer. The first coating layer is a cross-linked inorganic layer 3 containing nano magnetic materials 2. The second coating layer is a polymer layer 4 having at least one kind of hydrophilic-group-containing structural unit selected from hydroxyl groups and polyethylene glycol groups, and is adapted to form a covalent bond with the first coating layer and have a carboxyl group at an end of the polymer chain on a side opposite to the covalent bond.SELECTED DRAWING: Figure 1 【課題】耐酸性に優れ酸性水溶液で処理しても鉄の溶出が少なく、さらに水への分散性が良好であり、また、非特異吸着が少なく、並びに、粒子の比表面積が大きく生理活性物質の担持量が多い、免疫診断の高感度化が可能な磁性粒子を提供する。【解決手段】コア粒子１と、前記コア粒子表面に形成された第１の被覆層と、前記第１の被覆層の表面に形成された第２の被覆層を有する磁性粒子であって、前記第１の被覆層は、ナノ磁性体２を含有する架橋無機物層３であり、前記第２の被覆層は、ヒドロキシル基及びポリエチレングリコール基から選択される少なくとも１種の親水性基含有構造単位を有する重合体層４であり、第１の被覆層と共有結合を形成し、前記共有結合とは反対側の高分子鎖末端にカルボキシル基を有することを特徴とする、抗体結合用磁性粒子。【選択図】図１