This study aimed to guide future sensor studies against other pharmaceutical drugs by synthesizing Fe 3 O 4 NPs@MWCNT metallic nanoparticles (NPs). Side damage caused by excessive accumulation of tuberculosis drugs in the body can cause clots in the organs, and cause serious damage such as heart attack and respiratory failure, and threaten human life. Therefore, the development of sensors sensitive to various antibiotics in this study is important for human health. In this study, the sensitivity of Fe 3 O 4 NPs to tuberculosis drug (rifampicin) was evaluated by catalytic reaction using bare/GCE, MWCNT/GCE, and Fe 3 O 4 NPs@MWCNT/GCE electrodes. First of all, Fe 3 O 4 NPs were successfully synthesized for the study and MWCNT/GCE and Fe 3 O 4 NPs@MWCNT/GCE electrodes were formed with the modification of the MWCNT support material. It was observed that the Fe 3 O 4 NPs@MWCNT/GCE electrode gave the highest signal against the other electrodes. The morphological structure of Fe 3 O 4 NPs was determined by various characterization techniques such as Transmission Electron Microscopy (TEM), Fourier Transmission Infrared Spectroscopy (FTIR), ultraviolet–visible (UV–Vis), and X-ray differential (XRD) and the obtained NPs were used for sensor studies, and it was observed that the current intensity increased as the scanning speed of each electrode increased in CV and DPV measurements. The average size of Fe 3 O 4 NPs was found to be 7.32 ± 3.2 nm. Anodic current peaks occurred in the linear range of 2–25 μM. According to the results obtained from the measurements, the limit of detection (LOD) value was calculated as 0.64 μM limit of quantification (LOQ) 1.92 μM. [Display omitted] • An ultra-sensitive Rifampicin Electrochemical Sensor. • Fe 3 O 4 Nanoparticles anchored Multiwalled Carbon nanotube based sensor (Fe 3 O 4 NPs@MWCNT) • The detailed characterization of Fe 3 O 4 NPs@MWCNT. [ABSTRACT FROM AUTHOR]