Gold nanoparticles decorated poly-melamine modified glassy carbon sensor for the voltammetric estimation of domperidone in pharmaceuticals and biological fluids

Abstract

The electrochemical response of an unmodified glassy carbon (GCE), poly-melamine/GCE and gold nanoparticle (AuNP)/poly-melamine/GCE is compared in the present protocol for the sensitive and selective determination of domperidone (DOM). The AuNPs were synthesized in the laboratory and characterized using UV–visible spectroscopy and Transmission Electron Microscopy (TEM). Melamine was electropolymerized onto the glassy carbon surface using cyclic voltammetry and was investigated using Field Emission Scanning Electron Microscopy (FE-SEM) and Electrochemical Impedance Spectroscopy (EIS). The AuNP/poly-melamine/GCE exhibited the best electrochemical response among the three electrodes for the electro-oxidation of DOM, that was inferred from the EIS, cyclic and square wave voltammetry. The modified sensor showed a sensitive, stable and linear response in the concentration range of 0.05–100µM with a detection limit of 6nM. The selectivity of the proposed sensor was assessed in the presence of high concentration of major interfering molecules as xanthine, hypoxanthine, and uric acid. The analytical application of the sensor for the quantification of DOM in pharmaceutical formulations and biological fluids as urine and serum was also investigated and the results demonstrated a recovery of >95% with R.S.D of <5%.