Synthesis and characterization of graphene oxide- Cu NPs-Fe-MOF nanocomposite and its application to simultaneous determination of Eskazina and Dopamine in real samples

In this paper, a nanocomposite containing graphene oxide (GO), copper nanoparticles (Cu NPs) and iron based metal–organic framework (Fe-MOF) was successfully prepared with a simple method via ultrasound process. The synthesized GO-Cu NPs-Fe-MOF nanocomposite was characterized using FT-IR, Raman spectroscopy, XRD and FESEM, and used to fabricate a modified carbon paste electrode (CPE) for the determination of Eskazina (ESK) and simultaneous determination of ESK and Dopamine (DA) for the first time. The efficiency of the sensor toward electrocatalytic oxidation of ESK was evaluated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Using DPV technique, the calibration graph of ESK at the surface of modified electrode demonstrated the linear response over the range of 0.4 – 495.2 μM including two linear segments with a detection limit of 0.10 μM. Also, electrochemical sensing of both of the drugs was done at the GO-Cu NPs-Fe-MOF/CPE in acetate buffer solution (ABS; pH 6.0, 0.1 M). By DPV, the introduced electrode could separate DA and ESK signals as two strong well-defined voltammetric peaks. Eventually, the applicability and reliability of the introduced sensor was investigated for the determination of the drugs in pharmaceutical and biological samples satisfactorily.