Simultaneous voltammetric determination of paracetamol and domperidone based on a graphene/platinum nanoparticles/nafion composite modified glassy carbon electrode

Graphene oxide and hexachloroplatinic acid were electrochemically reduced on a glassy carbon electrode (GCE) surface so as to form a graphene (Gr)-platinum nanoparticles (PtNP) composite. This nano composite was then coated with nafion (NAF) film so as to form NAF/PtNP/Gr/GCE. In this work, an electrochemical method based on adsorptive stripping square wave voltammetry (AdSSWV) employing NAF/PtNP/Gr/GCE has been proposed for the subnanomolar determination of paracetamol (PCT) and domperidone (DOM) simultaneously. The electrode material was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The electrochemical performance of PCT and DOM on modified electrode was investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and chronocoulometry. A sixteen fold enhancement in the AdSSWV signal was observed at NAF/PtNP/Gr/GCE in pH 6.0, phosphate buffer, as compared to GCE. Under the optimized conditions, the method allowed simultaneous determination of PCT and DOM in the linear working range of 8.2 x 10(-6)-1.6 x 10(-9) M with detection limits (3 x SD/s) of 1.06 x 10(-10) and 4.37 x 10(-10) M for PCT and DOM respectively. The practical analytical utilities of the modified electrode were demonstrated by the determination of PCT and DOM in pharmaceutical formulations, human urine, and blood serum samples. This proposed method was validated by HPLC and the results are in agreement at the 95% confidence level. Simultaneous voltammetric determination of PCT and DOM has been reported for the first time. (C) 2015 Elsevier B.V. All rights reserved.