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

• Published in: Sensors and actuators. B, Chemical Vol. 128; no. 1; pp. 23 - 30
• Main Authors: Messina, Germán A., De Vito, Irma E., Raba, Julio
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 12.12.2007
• Subjects: Alkaline phosphatase; FIA; Helicobacter pylori; Immunosensor; p-Aminophenyl phosphate; Screen-printed electrodes; Alkaline phosphatase; Helicobacter pylori; Screen-printed electrodes; p-Aminophenyl phosphate; Immunosensor; FIA
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2007.05.024

This paper describes the development of a screen-printed immunosensor for the rapid and sensitive quantification of human serum immunoglobulin G (IgG) antibodies to Helicobacter pylori. This microorganism cause peptic ulcers and chronic gastritis, affecting around the 10% of the world population. Antibodies in the serum sample are allowed to react immunologically with the purified H. pylori antigens that are immobilized on graphite screen-printed electrodes (GSPE). The bound antibodies are quantified by alkaline phosphatase (AP) enzyme-labeled second antibodies specific to human IgG. p-Aminophenyl phosphate ( p-APP) was converted to p-aminophenol ( p-AP) by AP, and an electroactive product was quantified using Osteryoung square wave voltammetry (OSWV). The electrochemical detection can be done within 1 min and total assay time was 25 min. The calculated detection limits for electrochemical detection and the ELISA procedure are 0.5 and 1.8 U ml −1, respectively. Reproducibility assays were made using repetitive standards of H. pylori specific antibody (measured as the activity of the correspondent anti-serum's enzyme conjugated) and the intra- and inter-assay coefficients of variation were below 5%. The electrochemical immunosensor showed higher sensitivity and lower time consumed than the standard spectrophotometric detection ELISA method, demonstrate its potential usefulness for early assessment of human serum immunoglobulin G (IgG) antibodies to H. pylori.