A highly sensitive method for determination of guanine, adenine and epinephrine using poly-melamine film modified glassy carbon electrode

In this study, a polymerized film of melamine (PMel) was first prepared on the surface of glassy carbon electrode (GCE) in acidic solution by cyclic voltammetry. Scanning electron microscopy, Fourier transforms infrared spectroscopy and electrochemical techniques were used for characterization of the modified electrode surface. The electrochemical activity of the poly-melamine film modified glassy carbon electrode (PMel/GCE) was primarily tested for electrochemical catalyzes of guanine (G), adenine (A) and epinephrine (EP) in 0.1 M phosphate buffer solution (pH 4.5). The oxidation currents of G, A, and EP at the PMel/GCE increased 9, 7 and 13 times respectively compared with that of bare GCE. In the detection of the three aforementioned analytes using square wave voltammetry, the linear ranges of the peak currents at the PMel/GCE were 0.1–50 μM G, 0.1–60 μM A and 0.1–100 μM EP with detection limits of 0.08 μM G, 0.07 μM A and 0.05 μM EP, respectively. Furthermore, the prepared electrode displayed voltammetric responses with high sensitivity, good selectivity and reproducibility for A, G, and EP in optimal conditions, making it very suitable for determination of the three components.