Electrochemical immunoassays.

Abstract

Immunoassays are routinely used to detect, specifically, low levels of many antigens. The trend away from the use of radioisotopic labels has resulted in a proliferation of alternative labels, many of which have electrochemical activity. The more successful of these assays have used enzyme labels, coupled with amperometric or potentiometric methods of detection of the products. A number of assays have also been designed which are specifically electrochemical in origin, not simply adaptations of currently used spectrophotometric methods. Much effort has been expended in developing a potentiometric immunoassay that measures the change in potential that should occur when an antibody binds to its antigen. The use of electroactive labels has resulted in a number of assays for drugs. The advantages of an enzyme-linked mediated assay for lidocaine, an antiarrhythmic drug, are discussed.