Multiwalled Carbon Nanotubes Based Immunosensor for Diagnosis of Celiac Disease
Celiac Disease (CD) is an autoimmune disorder, represented by the ingestion of gliadin protein usually found in wheat, barley and rye. CD is closely associated with genes that code HLA-II antigens, mainly of DQ2 and DQ8 classes. Small intestinal biopsy is considered the gold standard for diagnosis of celiac disease. In addition, the most sensitive tests for the diagnosis of celiac disease include the increase in level of IgA isotype of anti-gliadin antibodies, connective tissue antibodies and tissue transglutaminase antibodies. In the present study, an amperometric immunosensor was fabricated for CD diagnosis using multiwalled carbon nanotubes screen printed electrode. Antigen (gliadin) was covalently linked to carbon nanotubes through 1-Ethyl-3-(3-dimethylaminopropyl carbodiimide) (EDC)- N-hydroxysuccinimide (NHS) cross linking chemistry. Different concentrations of anti-gliadin antibodies were added on working electrode surface and change in current was measured by Cyclic Voltammetry using redox indicator Potassium ferricyanide [K3Fe(CN)6]. Electrochemical studies showed that the immunosensor was able to detect the antibody concentration as low as 0.13ng/μl. Sensitivity of the immunosensor was found to be 119.2 (μA/cm2)/ng. The present sensor can be used for diagnosis of celiac patients who are sensitive to gluten ingestion.