Magnetic nanoparticles (NP) have found various important applications in nanotechnology and nanomedicine, because they can be manipulated by external magnetic field and can be functionalized on their surface. Although a variety of magnetic core shell NP are known present research focuses on new NP with better properties (reduced toxicity, high colloidal and chemical stability, wide scope of application) and more straightforward and reproducible syntheses. In this work, we report the synthesis of azido-functionalized polypyrrole (PPy)-based superparamagnetic core shell NP by surface initiated polymerization wherein miniemulsion technique have been applied in this field for the first time. The new NP are attractive for biomedical applications because the PPy is biocompatible, the shell can easily be functionalized by Cu-catalyzed click-reaction as shown by the introduction of biotin and the material exhibits superparamagnetic behavior. The surface initiated polymerization is carried out at new magnetite NP, which are stabilized by pyrrol-containing fatty acids. Although these starting NP lack a polymer shell, they show a remarkable stability and thus have the potential for further functionalization. The magnetic NP are characterized by various methods such as FTIR, X-ray photoelectron spectroscopy, magnetic measurements, thermal gravimetric analysis, and dynamic light scattering. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012