PROBLEM TO BE SOLVED: To provide a magnetic fluorescent nanoaggregate having an inverse structure. SOLUTION: The nano-aggregate and at least one polymer adsorbed on the surface of the nano-aggregate, which contains an organic fluorescent inner core containing a fluorescent organic molecule and magnetic nanoparticles in contact with the surface of the fluorescent inner core. A nanoaggregate system that includes, but does not include silica, functionalized silica, doped silica, graft silica or a combination thereof. The fluorescent organic molecule is of the following formula, and the magnetic nanoparticles are superparamagnetic nanoparticles selected from γ-Fe2O3 and Fe3O4. [Selection diagram] Fig. 3【課題】逆構造を有する磁性蛍光性ナノ集合体の提供。【解決手段】蛍光性有機分子を含む有機蛍光性内部コアと蛍光性内部コアの表面に接している磁性ナノ粒子とを含む、ナノ集合体およびナノ集合体の表面に吸着した少なくとも１つのポリマーを含み、但し、シリカ、官能基化シリカ、ドープシリカ、グラフトシリカまたはその組合せを含まない、ナノ集合体システム。蛍光性有機分子分子が下式であり、磁性ナノ粒子が、γーFe2O3およびFe3O4から選択される超常磁性ナノ粒子である。【選択図】図３
