Poly-Melamine Film Modified Sensor for the Sensitive and Selective Determination of Propranolol, a β-blocker in Biological Fluids

The study reports synthesis of poly-(melamine) film on the surface of edge plane pyrolytic graphite (EPPG) followed by its characterization using cyclic voltammetry, square wave voltammetry, field emission scanning electron microscopy (FE-SEM), Horizontal Attenuated Total Reflectance-infrared spectroscopy (HATR-IR) and electrochemical impedance spectroscopy (EIS). The p-(melamine) film coated EPPG has been used as a highly sensitive electrochemical sensor for the determination of propranolol, a beta-blocker. The p-(melamine)/EPPG sensor showed excellent electrocatalytic activity for the oxidation of propranolol by significant increment in the peak current and shift in the peak potential toward less positive potential. The fabricated sensor exhibited linear increase in the oxidation peak current with the increasing propranolol concentration in the range 0.1-800 mu M with the L.O.D. and L.O.Q. as 9 nM and 30 nM, respectively. The effect of interferents on the peak current response has been studied and it is observed that the common metabolites present in the biological fluid matrix did not interfere in the determination. The p-(melamine)/ EPPG sensor displayed advantages such as simple preparation, high sensitivity, excellent selectivity and good reproducibility toward determination of propranolol. To ensure the analytical applicability of the fabricated sensor, the method has been successfully demonstrated by determining propranolol in the commercial pharmaceutical formulations, human urine and plasma samples. (C) 2016 The Electrochemical Society. All rights reserved.