In this study, cerium salen encapsulated into dealuminated zeolite Y (CS@Z) was prepared through template synthesis method. This heterogeneous catalyst was characterized by XRD, FT-IR, SEM and EDS analysis. The amount of CS in the nanocage of zeolite was obtained 0.0846g/g of support. Pencil graphite electrode modified by CS@Z was applied for electrochemical ultra-sensitive determination of insulin. Parameters influencing the method were optimized. A linear range calibration curve from 0.05-50 nM of insulin with a detection limit of [12.8 (±0.6) pM] (based on S/N=3) and sensitivity of [44.3 (±0.8) μA μM-1] was observed at pH 7.4 and applied potential of 0.45 V by amperometry. The results demonstrated that the sensor can be used for the determination of insulin in the commercially available injections.
