simultaneous determination of ascorbic acid, dopamine, paracetamol, and tryptophan with cuxo-zno nanoparticlesdecorated polypyrrole and reduced graphene oxide modified glassy carbon electrode

in this work, we report the synthesis of cu_xo-zno nanoparticles-decorated polypyrrole and reduced graphene oxide composite (cu_xo-zno/ppy/rgo). this modified electrode was characterized by means of field emission-scanning electron microscopy (fe-sem) and x-ray diffraction (xrd) and was used for simultaneous determination of four biologic molecules namely ascorbic acid (aa), dopamine (da), paracetamol (par), and tryptophan (trp). electrochemical studies were carried out by using cyclic voltammetry (cv) and differential pulse voltammetry (dpv). this modified electrode (cuxo-zno/ppy/rgo/gce) exhibited excellent electrocatalytic activity, high sensitivity, low detection limit and fast response time. the linearity range was 10-475 μm, 0.05-420 μm, 0.5-400 μm and 0.5-185 μm for aa, da, par, and trp respectively and the detection limit was 0.3 μm, 39 nm, 10 nm and 50 nm for aa, da, par, and trp respectively. the sensor was used to analysis real sample and had satisfactory results.