Figure 4.

Preparation of streptavidin-immobilised fluorescent-magnetic nanocomposites; fluorescent microscopy images of nanocomposites excited with a 980 nm laser; (a) image of chain-like structures formed by nanocomposites in the presence of an external flat magnetic field; (b) image of stack-like structures formed by the same nanoparticles in an external needle-like magnetic field. From [28]

Corr et al. Nanoscale Research Letters 2008 3:87-104   doi:10.1007/s11671-008-9122-8