Figure 4.

The plasmonic and magnetic properties of the Fe3O4-loaded PHAuNPs. a Appearance of a bottle of particle water suspension. The particles can be dragged toward a permanent magnet. b Absorption spectrum of the particle water suspension, showing a broad peak centering at 750 nm. c Hysteresis loop of dried particle powder, showing that the suspension consists of a mixture of superparamagnetic and ferromagnetic nanoparticles.

Huang et al. Nanoscale Res Lett 2011 6:43   doi:10.1007/s11671-010-9792-x