A novel platform based on CoMnO-rGO/1-ethyl-3-methylimidazolium chloride modified carbon paste electrode for voltammetric detection of pethidine in the presence morphine and olanzapine.

The present work focuses on the development of a new electrochemical platform based on CoMnO-rGO/1-ethyl-3-methylimidazolium chloride modified carbon paste electrode (CoMnO-rGO/IL/CPE) for electrochemical determination of pethidine in the presence of biological species. For the first time, the electrooxidation mechanism of pethidine in presences of morphine and olanzapine is investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) technologies. The as-synthesized CoMnO-rGO nanocomposites are characterized by physicochemical measurements such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Field emission scanning electron microscopy (FE-SEM), and Fourier transform infrared (FT-IR). The obtained results illustrated synergistic interactions between rGO and CoMnO structures. Also, to investigate the electrode charge-transfer resistances, electrochemical features of the resulting nanocomposites are studied via electrochemical impedance spectroscopy (EIS) analysis. Based on the result, three segmented linear ranges are observed over the range 0.08-900 μM and detection limit of 0.024 μM. Over the 10.0-40.0 μM ranges of pethidine in phosphate buffer solution (PBS-pH 7.0), suitable diffusion coefficient of 5.67 × 10 cm s is evaluated by chronoamperometry technique (CHA). Finally, the CoMnO-rGO/IL/CPE with high sensitivity, selectivity and repeatability is successfully used for determination of pethidine in real sample and drug formulation.