Enzyme Immunoassay Using the Ammonia Gas-Sensing Electrode
Potentiometric membrane electrodes have been applied to immunological measurements both as direct immunosensors and as detectors of enzyme label activity in enzyme immunoassays (EIA). In the latter case, no universal Potentiometric sensor is available for EIA use but rather a distinct electrode type is matched with the class of enzyme label it is best suited to detect. The ammonia gas-sens ing electrode is one example and has the capability of detecting enzymes that catalyze ammonia producing reactions. Meyerhoff and Rechnitz (1979) first described the application of this gas-sensing electrode to EIA measurements through the use of a urease label for bovine serum albumin (BSA), a model protein analyte, and for cyclic AMP (adenosine monophosphate). In this chapter the general application of the ammonia gas-sensing electrode to immunoassay methods employing deaminating enzyme labels is examined for both a model hapten, dinitrophenyl (DNP), and one of clinical interest, Cortisol.
KeywordsAdenosine Deaminase Enzyme Electrode Phosphate Buffer Saline Buffer Enzyme Label Relative Standard Devia
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