Sonochemical synthesis of magnetic core–shell Fe 3O 4@ZrO 2 nanoparticles and their application to the highly effective immobilization of myoglobin for direct electrochemistry

Abstract

In this study, bifunctional Fe 3O 4@ZrO 2 magnetic core–shell nanoparticles (NPs), synthesized by a simple and effective sonochemical approach, were attached to the surface of a magnetic glassy carbon electrode (MGCE) and successfully applied to the immobilization/adsorption of myoglobin (Mb) for constructing a novel biosensor platform. With the advantages of the magnetism and the excellent biocompatibility of the Fe 3O 4@ZrO 2 NPs, Mb could be easily immobilized on the surface of the electrode in the present of external magnetic field and well retained its bioactivity, hence dramatically facilitated direct electron transfer of Mb was demonstrated. The proposed Mb/Fe 3O 4@ZrO 2 biofilm electrode exhibited excellent electrocatalytic behaviors towards the reduction of H 2O 2 with a linear range from 0.64 μM to 148 μM. This presented system avoids the complex synthesis for protecting Fe 3O 4 NPs, supplies a simple, effective and inexpensive way to immobilize protein, and is promising for construction of third-generation biosensors and other bio-magnetic induction devices.