Intracellular spatial control of fluorescent magnetic nanoparticles.

We report a facile intracellular manipulation of fluorescent magnetic Fe3O4-CdSe nanoparticles using magnetic force. The growth of CdSe quantum dots on Fe3O4 nanoparticles produces Fe3O4-CdSe nanoparticles with two distinct properties, fluorescence and superparamagnetism. After nonspecific surface modification using glutathione (GSH), the hydrophilic Fe3O4-CdSe@GSH nanoparticles can be easily uptaken by an HEK293T cell line. Confocal images indicate that the uptaken nanoparticles can be manipulated using a small magnet. The successful intracellular manipulation of magnetic nanoparticles may offer a new strategy for studying polarized cells.