Continuous-flow/stopped-flow system using an immunobiosensor for quantification of human serum IgG antibodies to Helicobacter pylori

Conventional methods, such as gastric biopsy, ELISA, culture, require a long time for the detn. of Helicobacter pylori infections. This study reports an amperometric immunoreactor for rapid and sensitive quantification of human serum IgG antibodies to H. pylori. Antibodies in the serum sample are allowed to react immunol. with the purified H. pylori antigens that are immobilized on a rotating disk. The bound antibodies are quantified by horseradish peroxidase (HRP) enzyme-labeled second antibodies specific to human IgG. HRP in the presence of hydrogen peroxide catalyzes the oxidn. of hydroquinone to p-benzoquinone. The electrochem. redn. back to hydroquinone is detected on a glassy carbon electrode surface at -0.15 V. The electrochem. detection can be done within 1 min, and the anal. time does not exceed 30 min. The calcd. detection limits for amperometric detection and the ELISA procedure are 0.6 and 1.9 U ml-1, resp. The amperometric immunoreactors showed higher sensitivity and lower time consumed than did the std. spectrophotometric detection ELISA method. It can also be used for rapid anal. in conventional and field conditions in biol., physiol., and anal. practices. [on SciFinder (R)]