Direct electrical communication between chemically modified enzymes and metal electrodes. 1. Electron transfer from glucose oxidase to metal electrodes via electron relays, bound covalently to the enzyme

Journal Article · Thu Mar 12 00:00:00 EST 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100290a001· OSTI ID:7042297

Degani, Y; Heller, A

Glucose-reduced glucose oxidase does not directly transfer electrons to conventional electrodes because the distance between its redox centers and the electrode surface exceeds, even on closest approach, the distance across which electrons are transferred at sufficient rates. Therefore, electrical communication between the redox centers of this enzyme and electrodes required either the presence, and diffusion to and from the enzyme's redox center, of O/sub 2/ and H/sub 2/O/sub 2/, or the presence of members of a redox couple, or the use of special electrodes like TTF/TCNQ. They show here that direct electrical communication between the redox center of a large enzyme molecule and a simple metal electrode can be established through chemical modification of the enzyme. When a sufficient number of electron-relaying centers are attached through covalent bonding to the protein of glucose oxidase, electrons are transferred from the enzyme's redox centers to relays that are closer to the periphery of the enzyme. Because some of the relays are located sufficiently close to the enzyme's surface, electrons are transferred at practical rates to the electrode. As a result, a glucose-concentration-dependent current flows in an electrochemical cell made with conventional electrodes when the electrolytic solution contains the relay-modified enzyme. Such a current does not flow when the solution contains the natural enzyme. Specifically, electrical communication is established between the FAD/FADH/sub 2/ centers of glucose oxidase and gold, platinum, or carbon electrodes through the covalent bonding of an average of 12 molecules of ferrocenecarboxylic acid per glucose oxidase molecule.

• Research Organization: AT and T Bell Labs., Murray Hill, NJ
• OSTI ID: 7042297
• Journal Information: J. Phys. Chem.; (United States), Vol. 91:6
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBON
ELECTRON TRANSFER
GLUCOSE
OXIDATION
GLUCOSIDASE
GOLD
PLATINUM
ELECTRODES
EXPERIMENTAL DATA
PH VALUE
ALDEHYDES
CARBOHYDRATES
CHEMICAL REACTIONS
DATA
ELEMENTS
ENZYMES
GLYCOSYL HYDROLASES
HEXOSES
HYDROLASES
INFORMATION
METALS
MONOSACCHARIDES
NONMETALS
NUMERICAL DATA
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
PLATINUM METALS
SACCHARIDES
TRANSITION ELEMENTS
400400* - Electrochemistry