▎ 摘　　要

This work presents a simple green approach for the chemical synthesis of cobalt oxide nano hexagons (Co3O4 NHs) with an average size of 160 +/- 40nm incorporated graphene nanosheets (GR). The techniques used to confirm the formation of GR-Co3O4 NHs are transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction spectroscopy (XRD). The dopamine (DA) sensor was fabricated by drop casting GR-Co3O4 NHs on the pre-cleaned glassy carbon electrode (GCE). GR-Co3O4 modified GCE displayed a sensitive and selective electrochemical determination of DA compared to only GR and Co3O4 NHs modified GCE. Our fabricated sensor showed a wide linear range from 0.2 to 3443M with low limit of detection (84nM) towards the determination of DA. The sensitivity of our fabricated sensor was calculated to be 108AmM(-1)cm(-2). As well, a significant storage stability, repeatability and reproducibility were attained by GR-Co3O4 NHs modified GCE. Human urine samples were targeted for the demonstration of practicality of our sensor.