In this work, the Fe3O4@SiO2@schiff-base of Mo(MNPs) was synthesized a multistep procedure and was simultaneously doped in to electropolymerized polypyrrole(PPy) film using the cyclicvoltammetry(CV) technique. Scanning electron microscopy(SEM), electrochemical impedance spectroscopy(EIS) and CV swereused to characterize the composite films. The PPy–(MNPs) modified gold(Au) electrode was used to determine Insulin using square-wave voltammetry (SWV). It was found that the prepared nanoparticles have excellent electrocatalytic activity towards insulin oxidation due to special properties of magnetic nanoparticles(MNPs). The common coexisting substances showed no interferences on the response of modified electrode to Insulin. The modified electrode indicated reproducible behavior and a high level stability during the experiments, making it particularly suitable for the analytical purposes
