Copper oxide–modified screen-printed carbon electrodes for the detection of mycobacterium tuberculosis infection treating drug: Isoniazid

This study presents the development of copper oxide–modified screen-printed carbon electrodes (CuO/SPCE) for the sensitive electrochemical detection of isoniazid (INZ). The electrodeposition of CuO on the surface of SPCE in a dilute CuSO 4 solution forms CuO amorphisms or clusters, which catalyze the oxidation of INZ. The sensor exhibited a linear response to INZ concentrations ranging from 4 to 200 μM with a correlation coefficient of 0.991 and a limit of detection (LoD) of 8.39 μM. Stability and reproducibility were confirmed through repetitive measurements with relative standard deviations of 0.27% and 1.20%, respectively. Interference studies demonstrated the sensor’s selectivity toward INZ, and a real sample analysis of pharmaceutical tablets yielded recovery rates ranging from 99.50 to 105.03%. Hence, regular monitoring of INZ dosage levels in human body fluids is critical, necessitating the development of sensitive, effective, and consistent methods to quantify INZ in clinical and pharmaceutical samples.  Graphical Abstract