Preparation of GCE modified with ZnO@CoFe2O4 magnetic nanoparticles and its application in electrocatalytic determination of Acetaminophen

In this work, a nanocomposite of zinc oxide (ZnO) and cobalt ferrite (CoFe2O4) was synthesised with a facile preparation method in order to fabricate a nanosensor for acetaminophen (AC) sensing. The ZnO nanoparticles were electrochemically deposited onto glassy carbon electrode (GCE) coated with magnetic nanoparticles CoFe2O4. The morphology and structure of ZnO@CoFe2O4 nanocomposite were investigated by scanning electron microscopy and energy dispersive X-ray. The performance of the proposed sensor was characterised with cyclic voltammetry and differential pulse-voltammetry techniques. The ZnO@CoFe2O4/GCE nanosensor shows excellent electrocatalytic activity for AC oxidation in phosphate buffer (pH=7) solution and it exhibits a good linear relationship and the low limit of detection (LOD). The ZnO@CoFe2O4/GCE showed good sensitivity, selectivity, stability, reproducibility, larger specific area and fast response in comparison with other reported sensors. The result calibration diagram of using the differential pulse-voltammetric technique has two linear ranges of 0.495-9.53 and 9.53-47.00 mu m, and the LOD for AC by this method obtained 0.36 mu m. The performance of this modified electrode was evaluated for measuring AC in some pharmaceutical formulations.