Amperometric Immunoassay

Abstract

An exciting new analytical technique based on amperometric devices used to measure immunoassays is reviewed in this article. The utility, ease, speed, simplicity, and many other advantages of performing amperometric immunoassays (AIAs) are discussed throughout the review. Limitations are also described, with electrochemical comparisons being made between AIAs and other conventional analytical methods, including potentiometric immunoassays. The review essentially consists of a general AIA overview, followed by sections devoted to amperometric electrode types, assay design, basic principles, automation, application, and future use. Operational features of oxygen gas selective electrodes and oxidoreductase probes are discussed for a better understanding of AIA principles. Characteristics, limits, advantages, and disadvantages of these different devices are presented. A variety of homogeneous and heterogeneous AIAs are described, together with many applications of the different assay formats available. AIAs are classified according to the electrode type employed, enzyme labels required, or electrochemical components involved. Important related AIAs discussed include pulse agglutination reactions and bioaffinity or displacement assays.

Direct Electrochemical Immunosensor for Polychlorinated Biphenyls

“…Capacitance changes at electrode−electrolyte interfaces resulting from Ab−Ag recognition have been used to develop electrochemical immunosensors ( , ). Also, the voltam metric (), amperometric (), and potentiometric ( , ) detection of Ab−Ag interactions have been accomplished through the application of redox-modified antigens or antibodies-to-electrode interfaces in the presence of analyte substances.…”

The New Era of Automated Immunoassay

“…Direct labeling with an electrochemically active compound is possible, but enzymatic amplification usually is needed for adequate sensitivity. [53][54][55][56] Unlabeled electrochemical detection also has been described (see discussion of surface phenomena in this section).…”