Continuous Flow / Stop Flow System Using an Immunobiosensor for Quantification of Human Serum IgG Antibodies to Helicobacter pylori

GERMÁN ALEJANDRO MESSINA; ANGEL TORRIERO; IRMA ESTER DE VITO; ROBERTO A. OLSINA; JULIO RABA

ANALYTICAL BIOCHEMISTRY

Elsevier

Año: 2005 vol. 337 p. 195 - 202

0003-2697

Conventional methods, such as gastric biopsy, enzyme-linked immunosorbent assay (ELISA), culture, require a long time for thedetermination of Helicobacter pylori infections. This study reports an amperometric immunoreactor for rapid and sensitive quantification of human serum immunoglobulin G (IgG) antibodies to H. pylori. Antibodies in the serum sample are allowed to reactimmunologically with the purified H. pylori antigens that are immobilized on a rotating disk. The bound antibodies are quantifiedby horseradish peroxidase (HRP) enzyme-labeled second antibodies specific to human IgG. HRP in the presence of hydrogen peroxidecatalyzes the oxidation of hydroquinone to p-benzoquinone. The electrochemical reduction back to hydroquinone is detectedon a glassy carbon electrode surface at 0.15 V. The electrochemical detection can be done within 1 min, and the analysis time doesnot exceed 30 min. The calculated detection limits for amperometric detection and the ELISA procedure are 0.6 and 1.9 U ml1,respectively. The amperometric immunoreactors showed higher sensitivity and lower time consumed than did the standard spectrophotometricdetection ELISA method. It can also be used for rapid analysis in conventional and field conditions in biological, physiological,and analytical practices.