Electrochemical determination of levodopa in the presence of uric acid using ZnO nanoflowers-reduced graphene oxide

Abstract

ZnO nanoflowers (ZnO NFs) were prepared by hydrothermal synthesis and graphene oxide nanosheets (GO NSs) were synthesized by the Hummer’s method. Then, ZnO NFs were dispersed in GO dispersion and sprayed onto ITO-coated glass. Finally, the ZnO NFs-GO NSs/ITO was annealed to form the ZnO NFs-rGO NSs/ITO, acting as the electrode for the determination of levodopa (LD) under the interference of uric acid (UA). The results reveal that the ZnO NFs are made up of nanorods with the diameter of ∼ 150 nm and the length of ∼ 2 µm and ZnO NFs are covered by rGO NSs. The ZnO NFs-rGO NSs/ITO electrode exhibits an enhanced electrochemical response due to its excellent redox activity, which shows a high sensitivity (0.66 µA µM−1), low measured detection limit (1 µM) and excellent selectivity for determination of LD. The electrode was used to detect the LD in the actual sample of human serum for practical application, revealing satisfactory results.