Synthesis of multifunctional magnetic nanoparticles (MFMNPs) is one of the most active research areas in advanced materials. MFMNPs that have magnetic properties and other functionalities have been demonstrated to show great promise as multimodality imaging probes. Their multifunctional surfaces also allow rational conjugations of biological and drug molecules,making it possible to achieve target-specific diagnostics and therapeutics.This review fi rst outlines the synthesis of MNPs of metal oxides and alloy sand then focuses on recent developments in the fabrication of MFMNPs of core/shell, dumbbell, and composite hybrid type. It also summarizes the general strategies applied for NP surface functionalization. The review further highlights some exciting examples of these MFMNPs for multimodality imaging and for target-specific drug/gene delivery applications.

Core/shell structured Fe3O4/Au and Fe3O4/Au/Ag nanoparticles are synthesized by depositing Au and Ag on the Fe3O4 nanoparticle surface in aqueous solution at room temperature. The control on shell thickness allows the tuning of plasmonic properties of the core/shell structure to be either red-shifted (to 560 nm) or blue-shifted (to 501 nm). Such magneto-optical nanoparticles should have great potentials for nanoparticle-based diagnostic and therapeutic applications.

A dopamine‐PEG based ligand is synthesized and used to stabilize monodisperse 9 nm Fe3O4 nanoparticles in physiological conditions and against non‐specific uptake by macrophage cells. Such stable nanoparticles can be used to enhance the efficiency in target‐specific drug delivery and to increase the signal‐to‐noise ratio in magnetic resonance imaging (MRI).