Accession Number : ADA219444


Title :   Amperometric Enzyme Electrodes


Descriptive Note : Technical rept. 1 Jul 1989-30 Jun 1990


Corporate Author : TEXAS UNIV AT AUSTIN DEPT OF CHEMICAL ENGINEERING


Personal Author(s) : Hauser, Alan K ; Heller, Adam


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a219444.pdf


Report Date : 01 Dec 1989


Pagination or Media Count : 40


Abstract : This was prepared to be published as two chapters in a book entitled 'Chemical Sensor Science', reviewing amperometric biosensors. Special emphasis is placed on transport characteristics. Three generations of amperometric enzyme electrodes have evolved during the past thirty years. The first generation was based on natural enzyme reactions, particularly reduction of oxygen to hydrogen peroxide and amperometric measurement of the oxygen consumed or the hydrogen peroxide performed. These electrodes are in extensive ex vivo use today and are being developed for in vivo applications in feedback loops for the control of blood glucose levels in diabetics. In the second generation electrodes, the natural oxidant, oxygen, was replaced by oxidizing members of fast redox couples, such as ferricinium or quinone derivatives. These diffused into the substrate-reduced enzymes, oxidized these and were reduced, then diffused out of the enzyme into the solution and then from the solution through a membrane to an electrode where they were reoxidized. The current measured represented the flux of the reduced redox mediators to the electrode. Amperometric biosensors based on the use of diffusing redox couples have been in production since 1987. The newest generation of biosensors is based on electrical 'wiring' of enzymes with redox macromolecules, that relay electrons from the substrate-reduced enzymes to the electrodes. The wired enzymes are bound to the surface of electrodes and communicate with these electrically.


Descriptors :   *ENZYMES , *ELECTROCHEMISTRY , *ELECTRODES , COUPLING(INTERACTION) , DETECTORS , PRODUCTION , REDUCTION , SURFACES , OXYGEN , CHEMISTRY , ELECTRONS , FEEDBACK , TRANSPORT , OXIDIZERS , MACROMOLECULES , PERSONNEL , BIOLOGICAL DETECTION , IN VIVO ANALYSIS , LOOPS , DIABETES , GLUCOSE , OXIDATION REDUCTION REACTIONS , BLOOD VOLUME , HYDROGEN PEROXIDE , RELAYS , BLOOD CHEMISTRY


Subject Categories : Biochemistry


Distribution Statement : APPROVED FOR PUBLIC RELEASE