Highly Sensitive and Selective Electrochemical Determination of Uric Acid in the Presence of Ascorbic Acid and Dopamine Using a Copper Nanoparticle-Tartrazine Nanocomposite Modified Glassy Carbon Electrode by Differential Pulse Voltammetry

Abstract

A new electrochemical biosensor was designed for the determination of uric acid by modifying the surface of the glassy carbon electrode with electrodeposited tartrazine and copper nanoparticles (Cu NPs/TAT) nanocomposite. Electrochemical investigations were administered using cyclic voltammetry and differential pulse voltammetry. The modified Cu NPs/TAT nanocomposite electrode was characterized by field emission scanning electron microscopy, mapping, X-ray diffraction, energy-dispersive X-ray spectroscopy, diffuse reflectance spectroscopy, and electrochemical impedance spectroscopy. The results showed an increase in surface conductivity. The modified electrode had linear ranges from 0.03 to 97 µM with a sensitivity of 0.258 µA µM−1 and from 115 to 1100 µM with a sensitivity of 0.0368 µA µM−1. The modified electrode showed a detection limit as low as 2.9 nM at a signal-to-noise ratio of three. In the interference study, this modified electrode had the ability to separate dopamine, uric acid, and ascorbic acid peaks. In addition, the sensor displayed high selectivity and sensitivity, good repeatability, and good stability, and was employed for uric acid determination in human serum samples with satisfactory results.