Electrochemical Determination of Phenylalanine in Biological, Food and Pharmaceutical Samples using a MnO₂/N‐doped Reduced Graphene Oxide Nanocomposite

Abstract

In this study, the MnO2/N‐doped reduced graphene oxide (NRGO) nanocomposite was synthesized and applied for the glass‐carbon electrode coating as working electrode for electrochemical phenylalanine determination. The structure, morphology, and composition of materials were characterized using appropriate methods. Optimal pH was investigated by injecting different amounts of phenylalanine into phosphate buffer solution and differential pulse voltammetry signal studying. Under optimal conditions, the calibration curve was linear in the range of 15–220 μM and the detection limit was 3.59 μM. The method shows acceptable selectivity in the presence of common interfering species in biological fluids. The method was successfully applied for the determination of the amino acid phenylalanine in blood plasma, food, and pharmaceutical samples. The results were evaluated by studying the amount of spiked recovery and statistical test with comparison to the high‐performance liquid chromatography method results and the accuracy and precision of the method for phenylalanine determining in real samples were confirmed.