▎ 摘　　要

Levels of serotonin above or below normal values in the human body can cause a variety of diseases, including depression, Alzheimer's disease, and irritable bowel syndrome. In this study, we developed a novel electrochemical sensor based on Ti3C2Tx-reduced oxide graphene (Ti3C2Tx-rGO) nanocomposite modified glassy carbon electrode for the detection of serotonin in human biofluids. The Ti3C2Tx-rGO nanocomposite was synthesized by hydrazine reduction followed by self-assembly, which was characterized using scanning electron microscopy, transmission electron microscopy coupled energy-dispersive X-ray analysis, and Raman spectroscopy. The obtained Ti3C2Tx-rGO nanocomposite could not only mitigate the restacking problem of Ti3C2Tx nanosheets but also provide a large surface area and effective active sites for improving the electrochemical performance of the nanocomposite. The electrochemical sensor fabricated based on the Ti3C2Tx-rGO nanocomposite showed high sensitivity, excellent specificity, and good stability for serotonin detection. Additionally, it was successfully used to determine serotonin in human blood plasma, and the results were within the expected range. The serotonin detection method demonstrated in this work is expected to be applied for the prevention and rapid diagnosis of serotonin-related diseases.