Simultaneous electroanalytical sensing of dopamine and epinephrine using TiO2/reduced graphene oxide nanocomposite modified glassy carbon electrode

This work introduces a novel electrochemical sensor for simultaneous determination of dopamine (da) and epinephrine (ep) by modifying a glassy carbon electrode (gce) with reduced graphene oxide (rgo) and titanium dioxide (tio2) nanoparticles. the rgo/tio2 nanocomposite characterization was investigated by using field emission scanning electron microscopy (fe-sem), elemental mapping, fourier-transform infrared spectroscopy (ftir), raman spectroscopy, x-ray diffraction analysis (xrd), and x-ray photoelectron spectroscopy (xps). cyclic voltammetry (cv) and differential pulse voltammetry (dpv) methods were used for electrochemical measurements. this study showed that the resultant rgo/ tio2 modified gce is highly sensitive and selective for the simultaneous determination of da and ep, and provided two linear responses rangeing from 5-180 and 180-1000 μm with a detection limit of 1.3 μm for da and two linear responses ranging from 5-20 and 20-1000 μm with a detection limit of 1.4 μm for ep. in addition, the electrochemical oxidation of da and ep was well recovered in pharmaceutical formulations.