A simple and versatile method for the introduction of electrochemical moieties onto the surface of Fe3O4 nanoparticles has been developed based on UV-induced thiol-ene click chemistry. Thiol-terminated Fe3O4 nanoparticles were synthesized and further reacted with vinylferrocence under 365 nm UV. The functionalized magnetic nanoparticles were characterized using a powder X-ray diffractometer (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscope (FTIR), and vibrating sample magnetometer (VSM). The resulting nanocomposites possess of magnetism and electrochemical activity. Based on the superparamagnetism of Fe3O4 nanoparticles and the electrocatalytic activity of ferrocene, a recyclable, magneto-controlled bioelectrocatalytic system for glucose oxidation is developed. The switching of the biocatalytic activity and recyclable usage of the ferrocene functionalized nanoparticles by means of the external magnet could provide a simple, green and convenient strategy for bioelectrosensing. (C) 2012 Elsevier Ltd. All rights reserved.