title: Electrochemical detection of celiac disease-related anti-tissue transglutaminase antibodies using thiol based surface chemistry.
abstract: Celiac disease is an autoimmune disorder that affects the gastrointestinal tract upon ingestion of gluten, which triggers the production of antibodies against gliadin and tissue transglutaminase, activating an inflammatory response and inducing tissue damage in the small intestine resulting in malabsorption. The measurement of these antibodies in an individual's blood can be used to screen for celiac disease and the criteria for definitive diagnosis is currently being revised to be based on serological analysis rather than biopsy. In the work reported here, an electrochemical immunosensor for the detection of human anti-tissue transglutaminase antibodies was developed, consisting of gold-based self-assembled monolayers of a carboxylic group terminated bipodal alkanethiol that is covalently linked to tissue transglutaminase, the antigen for the immunorecognition of circulating autoantibodies. The presence of the autoantibodies was recorded using horseradish peroxidase labeled anti-human antibodies, which provided an enzyme based electrochemical signal. Optimization and characterization of the surface of the sensor was carried out by electrochemical impedance spectroscopy and surface plasmon resonance. The immunosensor gave a stable quantitative response to different antibody concentrations after 30 min with a limit of detection of 390 ng/mL and an RSD of 9%, n=3. The developed immunosensor was tested with calibrator solutions as well as with real patients' samples, and the results compared to those obtained from Eurospital's Eu-tTG IgA and IgG ELISA kits, showing an excellent degree of correlation.
authors.affiliation: Department d'Enginyeria Quimica, Universitat Rovira i Virgili, Avinguda Països Catalans 26, 43007 Tarragona, Spain.
authors.forename: Samuel
authors.initials: S
authors.lastname: Dulay
authors.affiliation: Department d'Enginyeria Quimica, Universitat Rovira i Virgili, Avinguda Països Catalans 26, 43007 Tarragona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Lozano-Sánchez
authors.affiliation: Sensor Research Laboratory, Department of Chemistry, University of the Western Cape, Bellville, 7535 Cape Town, South Africa.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Iwuoha
authors.affiliation: Department d'Enginyeria Quimica, Universitat Rovira i Virgili, Avinguda Països Catalans 26, 43007 Tarragona, Spain.
authors.forename: Ioanis
authors.initials: I
authors.lastname: Katakis
authors.affiliation: Department d'Enginyeria Quimica, Universitat Rovira i Virgili, Avinguda Països Catalans 26, 43007 Tarragona, Spain; Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys, 23, 08010 Barcelona, Spain.
authors.forename: Ciara K
authors.initials: CK
authors.lastname: O'Sullivan
mesh_terms: D001323:Autoantibodies / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000379:methods*; D002446:Celiac Disease / Q000175:diagnosis* / Q000473:pathology; D006046:Gold / Q000737:chemistry; D006801:Humans; D013438:Sulfhydryl Compounds / Q000737:chemistry; D020349:Surface Plasmon Resonance; D011503:Transglutaminases / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D001323:Autoantibodies; D013438:Sulfhydryl Compounds; D006046:Gold; D011503:Transglutaminases