Simultaneous detection of ascorbic acid, dopamine, and uric acid using an rGO/PE/PVP@ HPMC/GCE electrode in biological matrices

Abstract The simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is crucial for biomedical and clinical diagnostics. Herein, we present a highly sensitive and selective electrochemical sensor based on a modified glassy carbon electrode (GCE) functionalized with hydroxypropyl methylcellulose (HPMC), polyvinylpyrrolidone (PVP), and 3D reduced graphene oxide/pentaerythritol (3D rGO/PE). The structural and morphological properties of the composite were characterized using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Electrochemical analysis demonstrated the remarkable electrocatalytic activity of 3D rGO/PE/PVP@HPMC/GCE for the oxidation of AA, DA, and UA, with peak potential separations of 214, 133, and 346 mV for DA-AA, DA-UA, and UA-AA, respectively. Under optimized conditions, the sensor exhibited wide linear detection ranges of 4.0 µM to 1.0 mM (AA), 0.2–100 µM (DA), and 1.0–100 µM (UA), with detection limits of 0.82, 0.002, and 0.025 M, respectively. The sensor demonstrated excellent sensitivity, selectivity, reproducibility, and stability, making it a promising platform for real-sample analysis.