Poly(Allura Red AC)-Modified Glassy Carbon Electrode: Electropolymerization, Characterization, and Application in Uric Acid Detection

Abstract

In this study, the electropolymerization, electrochemical characterization, and analytical applicability of a poly(Allura Red AC)-modified glassy carbon electrode were systematically investigated. Electropolymerization parameters, including monomer concentration, buffer type, pH, and ionic strength, were optimized to obtain a stable and electroactive poly(Allura Red AC) film. The resulting polymer film was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, surface coverage analysis, electroactive surface area determination, and pH-dependent electrochemical studies. The modified electrode exhibited enhanced electrocatalytic activity toward the oxidation of uric acid, enabling sensitive voltammetric determination. Under optimized conditions, the sensor showed a linear range of 0.2–40 μM and low detection limits of 7.64 nM and 6.47 nM by cyclic voltammetry and differential pulse voltammetry, respectively. The developed methods were successfully applied to protein-free human serum samples, providing accurate recoveries and no prominent interfering peaks within the uric acid oxidation potential window. This work provides a comprehensive understanding of the formation and electrochemical properties of poly(Allura Red AC) films while demonstrating their applicability as an electrocatalytic sensing interface for sensitive uric acid determination in biological samples.