The present study utilized a chemical reaction to create (3-aminopropyl) triethoxysilane (APTES)-functionalized Nb2CTx MXene nanosheets (Nb2CTx-APTES), which were then employed to modify carbon cloth yarn (CCY). The APTES modification of Nb2CTx MXene nanosheets improved the colloidal stability and electrochemical activity, ultimately resulting in the development of a more effective sensing platform for the electrochemical detection of the immunosuppressant drug mycophenolate mofetil (MMF) from artificial human serum samples. The sensor developed in this study exhibited a reliable range of detection for MMF, ranging from 10 to 100 μM, which is consistent with the typical dosage levels prescribed to patients (approximately 18 μM). This capacity to accurately quantify MMF concentrations within this range holds significant potential for improving patient care, particularly for organ transplant surgeries, by enhancing the electrochemical sensing of immunosuppressant drugs. The sensor also showed very high selectivity, reproducibility and good recovery percentage in human serum samples, with a limit of detection (LOD) of 1 μM. The results of this study are of great importance for biomedical research and clinical applications. © 2023 American Chemical Society