Three-dimensional ZnO nanosheet spheres/graphene foam for electrochemical determination of levodopa in the presence of uric acid

Abstract The ZnO nanosheet spheres (ZnO NSSs) have been hydrothermally synthesized on the surface of graphene foam (GF). A series of characterization techniques, such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were employed to analyze the morphology and structure of ZnO NSSs/GF. The fabricated ZnO NSSs/GF was used to detect levodopa (LD) by electrochemical methods including cyclic voltammetry (CV) and differential pulse voltammetry (DPV). As a working electrode, the ZnO NSSs/GF exhibits a high sensitivity of 0.66 μA·μM −1 and a low measured limit of detection of 1 μM. It shows an excellent selectivity in the presence of uric acid (UA). Furthermore, it has been successfully applied in human urine samples.