The development of efficient and accurate methods for detecting antipsychotic drugs is essential for preventing drug abuse. In this study, we designed a 2D/2D molybdenum diselenide/vanadium carbide (MoSe2/VC) nanocomposite for the electrochemical detection of chlorpromazine (CLPZ). Additionally, the cytotoxic properties of the MoSe2/VC nanocomposite were evaluated to assess its impact on cell health. The morphological structure and physical properties were thoroughly characterized using spectroscopic and microscopic techniques. Under optimized experimental conditions, the MoSe2/VC modified electrode exhibited excellent linearity (0.01–462 μM), a limit of detection of (0.013 ± 0.03 μM), high sensitivity (2.095 ± 0.04 μA μM–1 cm–2), robust selectivity (<5 %), and reproducibility of 2.21 % for CLPZ. The enhanced performance of the MoSe2/VC nanocomposite can be attributed to synergistic effects, increased surface area, unique structural characteristics, high conductivity, exceptional electrocatalytic activity, and a greater number of active surface sites, all of which contribute to improved CLPZ detection performance. Notably, the proposed sensor was employed for the quantitative analysis of CLPZ in spiked real samples, achieving satisfactory recoveries of 97.1–99.2 %. Furthermore, cell viability studies conducted with L-929 fibroblast cells demonstrated high biocompatibility, with cell survival rates exceeding 82 %. These findings highlight the promise of the MoSe2/VC nanocomposite-based electrochemical sensor as an affordable, effective, and dependable tool for environmental monitoring and safeguarding public health.