Interfacially assembled PdAuCo/rGO nanocomposite for amperometric determination of roxadustat in spiked human serum

Roxadustat (ROX) has been employed as a groundbreaking oral alternative for the treatment of anemia associated with chronic kidney disease. In this work, a PdAuCo/rGO-modified glassy carbon electrode (GCE) was developed for the amperometric determination of ROX through its electrocatalytic oxidation at +0.7 V versus Ag/AgCl in phosphate buffer (pH 8). PdAuCo/rGO was prepared by liquid–liquid interfacial chemical reduction, with the toluene/water boundary serving as an assembly region and interfacial confinement proposed to contribute to the observed porous morphology with bowl-like features. The electrocatalytic performance of the synthesized catalyst to detect ROX is investigated via electrochemical techniques including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometric. The resulting modified electrode exhibited an enhanced anodic response towards ROX compared with bare GCE. The PdAuCo/rGO-modified GCE (PdAuCo-rGO/GCE) depicted two linear calibration ranges for ROX determination, 0.05–20 and 20–1600 nM, with a limit of detection (LOD) of 0.016 nM. Furthermore, the modified GCE displays acceptable selectivity, reproducibility, stability, and repeatability. Finally, the sensor was applied to ROX determination in the spiked human serum samples, yielding recoveries of 98.9–100.5%.