DEVELOPMENT OF A FLOW-THROUGH IMMUNOASSAY SYSTEM

A semi-automated how-through immunoassay system consisting of an amper ometric immunosensor and reagent flow arrangements has been developed. The amperometric immunosensor is based on a high-surface-area carbon immunoelectrode. The novel principle of flow immunoelectrode based on highly dispersed carbon material which acts as both an immunosorbent a nd an immunoelectrode was employed. The immunoelectrode is designed to be a disposable sensing element. The 'sandwich' scheme of immunoassay has been used and iodine formed as a result of the enzymatic oxidatio n of iodide by peroxidase-label has been detected amperometrically. Th e overall time of analysis including flowing of analyte, flowing of an tigen, washing and detecting stages is as low as 17 min. The developed system allows fast determination of rabbit IgG (used as a model analy te) with a low detection limit in the 10(-11) M range and may easily b e adapted for detection of various other analyses. The immunoassay sys tem has the potential for miniaturization and complete automation allo wing its use in laboratory setting as well as in field conditions. (C) 1998 Elsevier Science S.A. All rights reserved.