Electrochemical Enzyme Immunoassay for Detection of Toxins

摘要

There is a need for sensors that provide direct, real-time measurements to detectand diagnose toxins in biological samples. We evaluated and developed a new biosensor design that combines advantages of immunoassay with electrochemical response for this purpose. The technology permits developing small toxin measuring devices for field use that are sensitive, specific and reliable. The specific objective of the Phase I work was to prove the principle of electrochemical enzyme immunosensors to detect small molecules in biological samples. In order to achieve the objective of the Phase I research the following work was carried out. Glucose oxidase and horseradish peroxidase were immobilized on colloidal gold. Colloidal gold-enzyme (Aurozyme) was deposited on two different electrode materials. A ferrocene-DNP conjugate was synthesized. Anti-DNP antibody was incorporated into the sensor. The completed sensor was optimized and demonstrated the immunochemical detection of antigen. The results of this work are demonstration of an amperometric enzyme immunoelectrode for immunoassays of small chemical molecules, based on the principle of coupling the immunochemical reaction to the electrode response by using a soluble electrochemically active mediator. Toxin detection; Electrochemical; Enzyme immunoassay; Biosensor; Biological sample.