Voltammetric Behavior of Isoniazid and Its Electroanalytical Determination at Carbon Nanotubes-CTAB Modified Glassy Carbon Electrode

An electrochemical sensor for sensitive determination of isoniazid (INH) using multi-walled carbon nanotubes-cetyltrimethyl ammonium bromide (CTAB) surfactant composite on the surface of a glassy carbon electrode was developed. The peak current increased greatly compared with bare GCE and MWCNT/GCE electrode. The oxidation process was irreversible over pH range studied and exhibited a diffusion controlled behavior. The current response was found to be directly proportional to the concentration of INH in the concentration range of 1.0×10-7 M to 1.2×10-6 M with a limit of detection (LOD) of 2.14×10-9 M. The modified electrode showed good selectivity and reproducibility. The developed analytical method was successfully applied to isoniazid determination in human serum and urine samples. This method can be employed in clinical analysis, quality control and routine determination of drugs in pharmaceutical formulation.