Synthesis of 5-[(2-hydroxynaphthalen-1-yl)diazenyl]isophthalic acid and its application to electrocatalytic oxidation and determination of adrenaline, paracetamol, and tryptophan

Abstract

In this study, Au nanoparticles/poly 5-[(2-hydroxynaphthalen-1-yl)diazenyl] isophthalic acid film modified glassy carbon electrode (AuNPs/poly(NDI)/GCE) has shown excellent electrocatalytic activity toward the oxidation of adrenaline (ADR), paracetamol (PAC), and tryptophan (Trp). The bare glassy carbon electrode (GCE) fails to separate the oxidation peak potentials of these molecules, while the poly(NDI) film modified electrode can resolve them. Electrochemical impedance spectroscopy (EIS) indicates that the charge transfer resistance of the bare electrode decreases as 5-[(2-hydroxynaphthalen-1-yl)diazenyl] isophthalic acid is electropolymerized on the bare electrode. Furthermore, EIS exhibits enhancement of electron transfer kinetics between analytes and the electrode after electrodeposition of Au nanoparticles. Differential pulse voltammetry results show that the electrocatalytic current increases linearly in the ranges of 0.01–680.0μmolL−1 for ADR, 0.05–498.0μmolL−1 for PAC, and 3.0–632.0μmolL−1 for Trp; with detection limits (S/N=3) of 0.009μmolL−1, 0.005μmolL−1, and 0.09μmolL−1 for ADR, PAC, and Trp, respectively. The proposed method has been successfully applied for simultaneous determination of ADR, PAC, and Trp in biological samples.