Kobra Salimiyan Rizi - Antimicrobial Resistance Research Center, Department of Medical Bacteriology and Virology, Qaem University Hospital, School of Medicine, Mashhad University of MedicalSciences, Mashhad, Iran.
Majid Rezaei - Medical Toxicology Research Center, Mashhad University of Medical Sciences, Mashhad,Iran. Department of Modern Sciences and Technologies, School of Medicine, Mashhad Universityof Medical Sciences, Mashhad, Iran.
Ehsan Aryan - Antimicrobial Resistance Research Center, Department of Medical Bacteriology and Virology, Qaem University Hospital, School of Medicine, Mashhad University of MedicalSciences, Mashhad, Iran.
Zahra Meshkat - Antimicrobial Resistance Research Center, Department of Medical Bacteriology and Virology, Qaem University Hospital, School of Medicine, Mashhad University of MedicalSciences, Mashhad, Iran.

Tuberculosis disease as an infectious bacterial disease was caused by Mycobacterium tuberculosis complex members. Due to the low growth rate and fastidious nature of Mycobacterium tuberculosis, the diagnosis of this pathogen has been generally difficult and time-consuming. The conventional detection methods include acid-fast bacilli microscopy and culture sample on Löwenstein– Jensen medium. In the sputum smear microscopy method, the bacteria are examined in sputum samples by a microscope, which associates with low detection accuracy and demand for skilled personnel. According to the existence limitations of the diagnosis methods for TB, it is needed a sensitive and costeffective technique for the diagnosis of TB. Recent advances in the development of electrochemical DNA biosensors based on nanomaterials have attractedsubstantial attention towards the potential application of medical diagnosis, gene analysis, food safety and environmental monitoring(1-3).Materials and Methods In the present study, a novel labeled DNA biosensor was developed for the highly sensitive detection of DNA of M. tuberculosis, using carbon nanotubes(CNTs), polypyrrole and hydroxyapatite nanoparticles as a sensing platform with a glassy carbon electrode. Methylene blue dye was used as label in this study.Conclusion: The nano-electrochemical DNA biosensor showed good stability and high specificity and provides a new strategy for clinical M. tuberculosis diagnostics and probably also for pathogenic bacteria in general.

Nano-electrochemical biosensor, Mycobacterium tuberculosis, carbonnanotubes, tuberculosis