A simple sonochemical assisted synthesis of nanocomposite (ZnO/MWCNTs) for electrochemical sensing of Epinephrine in human serum and pharmaceutical formulation

Herein, the electrochemical sensor was designed based on ZnO nanoparticles (NPs) and multi-walled carbon nanotubes (MWCNTs) for the sensitive and selective determination of Epinephrine (EP). ZnONPs was decorated on MWCNTs with the help of ultra-sonication to produce a nanocomposite (ZnO/MWCNTs), which was later dispersed on the surface of glassy carbon electrode (GCE). The morphology and characterization of nanocomposite were examined by using HR-TEM, FE-SEM, FT-IR and EDS techniques. The performance of ZnO/MWCNTs/GCE was evaluated by using various electrochemical methods such as CV, DPV and EIS. ZnO/ MWCNTs/GCE showed good electrocatalytic activity in terms of EP oxidation by giving much higher peak currents than those obtained at bare GCE and MWCNTs/GCE. The fabricated sensor demonstrated good selectivity, reproducibility and stability. The performance of the fabricated sensor was good in terms of evaluating the kinetic parameters such as heterogeneous rate constant and the number of electrons involved in the reaction. The analytical performance of the developed method towards the determination of EP endowed linear dynamic range from 0.4 mu M to 2.4 mu M with a detection limit of 0.016 mu M. The practical application of the fabricated sensor was demonstrated by determining EP in spiked human blood serum and adrenaline titrate injection samples.