H Keypour - Chemistry Department, Bu-Ali Sina University, Hamedan, Iran
M Balali - Chemistry Department, Bu-Ali Sina University, Hamedan, Iran

In this work, the Fe3O4@SiO2@schiff-base ofMo(MNPs) was synthesized a multistep procedure andwas simultaneously doped in to electropolymerizedpolypyrrole(PPy) film using the cyclicvoltammetry(CV)technique. Scanning electron microscopy(SEM),electrochemical impedance spectroscopy(EIS) and CVswereused to characterize the composite films. The PPy–(MNPs) modified gold(Au) electrode was used todetermine Insulin using square-wave voltammetry (SWV).It was found that the prepared nanoparticles have excellentelectrocatalytic activity towards insulin oxidation due tospecial properties of magnetic nanoparticles(MNPs). Thecommon coexisting substances showed no interferences onthe response of modified electrode to Insulin. Themodified electrode indicated reproducible behavior and ahigh level stability during the experiments, making itparticularly suitable for the analytical purposes.

Electrochemical impedance spectroscopy, Composite film electrode, magnetic nanoparticles, Insulin