Screen-printed immunosensor for quantification of human serum IgG antibodies to Helicobacter pylori

GERMÁN ALEJANDRO MESSINA; IRMA ESTER DE VITO; JULIO RABA

SENSORS AND ACTUATORS B-CHEMICAL

Año: 2007 vol. 128 p. 23 - 30

0925-4005

AbstractThis paper describes the development of a screen-printed immunosensor for the rapid and sensitive quantification of human serum immunoglobulinG (IgG) antibodies to Helicobacter pylori. This microorganism cause peptic ulcers and chronic gastritis, affecting around the 10% of the worldpopulation. Antibodies in the serum sample are allowed to react immunologically with the purified H. pylori antigens that are immobilized ongraphite screen-printed electrodes (GSPE). The bound antibodies are quantified by alkaline phosphatase (AP) enzyme-labeled second antibodiesspecific to human IgG. p-Aminophenyl phosphate (p-APP) was converted to p-aminophenol (p-AP) by AP, and an electroactive product wasquantified using Osteryoung square wave voltammetry (OSWV). The electrochemical detection can be done within 1 min and total assay time was25 min. The calculated detection limits for electrochemical detection and the ELISA procedure are 0.5 and 1.8Uml−1, respectively. Reproducibilityassays were made using repetitive standards of H. pylori specific antibody (measured as the activity of the correspondent anti-serum’s enzymeconjugated) and the intra- and inter-assay coefficients of variation were below 5%. The electrochemical immunosensor showed higher sensitivityand lower time consumed than the standard spectrophotometric detection ELISA method, demonstrate its potential usefulness for early assessmentof human serum immunoglobulin G (IgG) antibodies to H. pylori.