  The elaboration of multimodal nanoparticles stimulates tremendous interest
owing to their numerous potentialities in many applicative fields like
optoelectronics, photonics and especially bioimaging. The concomitant
association of various properties (optical, electrochemical, magnetic) allows
for the use of complementary stimuli in order to probe the interactions between
the nanoparticles and their surroundings.Nanoparticles (NPs) have thus become
highly praised tools to image cells and tissues with a large contrast
compatible with the dimensions of biological materials and the existence of
quantum confinement effects induced by the reduced dimensions. In this context,
the combination of magnetism and emissive properties such as fluorescence
appears particularly attractive for non-invasive investigations, cell sorting
or drug vectorization. Therefore, combining both fluorescence and magnetism
requires the delicate construction of hybrid assemblies. Most of the magnetic
nanoparticles are made of metallic oxides or alloys, e.g. gamma-Fe2O3, Fe3O4,
FePt, while the target fluorescent entities are often organic dyes or quantum
dots (QDs).
