We developed a novel 2-thiolbenzimidazole modified glassy carbon electrode for the sensitive determination of Cd(II) ion in human plasma. The developed electroanalytical sensor was characterized by CV, RAIRS, EIS, XPS and AFM. The nanosensor shows better sensitivity toward Cd(II) ion determination in comparison with previously used different kinds of electrodes. In addition, the construction of electrode based on 2-thiolbenzimidazole is relatively simpler and cheaper. Moreover, the developed electrode was successfully applied to human plasma samples for the determination of Cd(II). Hence, the sensitivity and relatively high stability of the electrode will open a new way for the determination of the heavy metal ions.