▎ 摘　　要

The current study focused on the creation of a gold and graphene hybrid nanostructure modified glassy carbon electrode (Au/GO/GCE) as an electrochemical sensor for the detection of nandrolone (ND) as a doping agent in blood and urine samples. The creation of a well-crystallized Au/GO nanohybrid structure was validated by the results of structural investigations. The electrochemical properties of Au/GO/GCE as ND sensors were studied using the DPV approach, which revealed a stable and selective response to ND, as well as a favorable and even superior performance of Au/GO/GCE than previous reported ND sensors. The linear range (1 to 100 ??M), sensitivity (0.3547 ??A/??M), and limit of detection (4 nM) of Au/GO/GCE were calculated. The practical application of a developed ND sensor was investigated in order to determine the ND in the serum and urine of four young athletes aged 20 to 30 years who were administered nandrolone decanoate subcutaneously. The results showed that the DPV and ELISA analyses agreed relatively well, and the resulting RSD values ranged from 3.10 percent to 4.33 percent, showing that the developed electrochemical ND sensor can be used as a viable sensing approach for determining ND in human biological fluids.