Imperial Chemical Industries Limited

Medisense, Inc.

Cranfield Biotechnology Ltd.

Genetics International, Inc.

Other

National Research Development Corporation

Irving J Higgins

Hugh A Hill

Graham Davis

James Michael McCann

Elliot V Plotkin

Timothy David Gibson

John R Woodward

John Bolbot

David A Griffiths

Stephen Birch

Eric D'Costa

William J Aston

Hugh Allen Hill

A sensor system that detects a current representative of a compound in a liquid mixture features a two-electrode strip adapted for releasable attachment to signal readout circuitry. The strip comprises an elongated support (preferably flat) adapted for releasable attachment to the readout circuitry; a first conductor and a second conductor each extend along the support and comprise means for connection to the circuitry. An active electrode, positioned to contact the liquid mixture and the first conductor, comprises a single layer deposit of an enzyme capable of catalyzing a reaction involving the compound, a conductive material and an electron mediator, capable of transferring electrons between the enzyme-catalyzed reaction and the first conductor. A reference electrode is positioned to contact the mixture and the second conductor. The system includes circuitry adapted to provide an electrical signal representative of the current. The two-electrode strip is manufactured, e.g., by screen printing an admixture of an enzyme, a conductive material, and a mediator as a single layer onto the substrate.

Strip electrode with screen printing

A sensor system that detects a current representative of a compound in a liquid mixture features a two-electrode strip adapted for releasable attachment to signal readout circuitry. The strip comprises an elongated support (preferably flat) adapted for releasable attachment to the readout circuitry; a first conductor and a second conductor each extend along the support and comprise means for connection to the circuitry. An active electrode, positioned to contact the liquid mixture and the first conductor, comprises a single layer deposit of an enzyme capable of catalyzing a reaction involving the compound, a conductive material, and an electron mediator, capable of transferring electrons between the enzyme-catalyzed reaction and the first conductor. A reference electrode is positioned to contact the mixture and the second conductor. The system includes circuitry adapted to provide an electrical signal representative of the current. The two-electrode strip is manufactured, e.g., by screen printing, an admixture of an enzyme a conductive material, and a mediator as a single layer onto the substrate.

A sensor system that detects a current representative of a compound in a liquid mixture features a two-electrode strip adapted for releasable attachment to signal readout circuitry. The strip comprises an elongated support (preferably flat) adapted for releasable attachment to the readout circuitry; a first conductor and a second conductor each extend along the support and comprise means for connection to the circuitry. An active electrode, positioned to contact the liquid mixture and the first conductor, comprises a deposit of an enzyme capable of catalyzing a reaction involving the compound and (preferably) an electron mediator, capable of transferring electrons between the enzyme-catalyzed reaction and the first conductor. A reference electrode is positioned to contact the mixture and the second conductor. The system includes circuitry adapted to provide an electrical signal representative of the current. The two-electrode strip is manufactured, e.g., by screen printing the enzyme (and preferably the mediator) onto the substrate.

Electrochemical metal analysis

Colorimetric enzymic analysis

A sensor system that detects a current representative of a compound in a liquid mixture features a two-electrode strip adapted for releasable attachment to signal readout circuitry. The strip comprises an elongated support (preferably flat) adapted for releasable attachment to the readout circuitry; a first conductor and a second conductor each extend along the support and comprise means for connection to the circuitry. An active electrode, positioned to contact the liquid mixture and the first conductor, comprises a deposit of an enzyme capable of catalyzing a reaction involving the compound and (preferably) an electron mediator, capable of transferring electrons between the enzyme-catalyzed reaction and the first conductor. A reference electrode is positioned to contact the mixture and the second conductor. The system includes circuitry adapted to provide an electrical signal representative of the current. The two-electrode strip is manufactured, e.g., by screen printing an admixture of enzyme, a conductive material, and a mediator as a single layer onto the substrate.

Strip electrode including screen printing of a single layer

This invention relates to equipment and methods for detecting the presence of, measuring the amount of, and/or monitoring the level of, one or more selected components in a liquid mixture, employing an electrode sensing system. We have discovered that a class of mediating compounds has extremely useful properties for mediating the transfer of charge between enzyme-catalyzed reactions and electrode surfaces (15) in electrode sensing systems. Specifically, the specification discloses as electrode sensor mediators, organometallic compounds composed of at least two organic rings, each of which has at least two double bonds in a conjugated relationship; a metal atom is in electron-sharing contact with those rings. An enzyme capable of catalyzing a reaction at a rate representative of the selected compound concentration is in contact with an assay mixture, and the mediator compound transfers charge between the enzyme and the conductive surface of the electrode at a rate representative of the enzyme catalyzed reaction rate.

Sensor for components of a liquid mixture

A sensor electrode to detect one or more components in a liquid mixture comprises an electrically conductive material having at least an an external surface, the combination of an enzyme catalytic for a reaction of the desired component, and a mediator compound which transfers electrons from the enzyme to the electrode when such catalytic activity takes place. It can be used as an in vivo glucose sensor either with a silver electrode coated with e.g. glucose oxidase and a polyviologen as the mediators, or with a particulate carbon electrode, glucose oxidase and chloranil or fluoranil as mediator. Another system is to use bacterial glucose dehydrogenase or glucose oxidase as the enzyme and/or ferrocene or a ferrocene derivative as the mediators compound to give electrodes with improved linearity, speed of response and insensitivity to oxygen.

A process of oxidizing a hydrocarbon which is an alkane or alkene or substituted alkane or alkene by contacting it with a culture of a bacterium as deposited under accession number NCIB 11613 or a mutant or derivative thereof which is capable of utilizing an alkane having from 6 to 28 carbon atoms as a source of carbon and energy or an enzyme extract thereof, and separating an oxidized derivative of the hydrocarbon.

Microbiological oxidation process

Microbiological oxidations of organic compounds including C6 to C28 alkanes, C2 to C18 alkenes and cyclic compounds such as cyclohexane and benzene carried out using as catalysts methane-utilizing bacteria adapted to utilize methanol as a carbon source. The application also covers methane-utilizing bacteria adapted to utilize methanol as a carbon source and a method for producing such bacteria. In the method methane-utilizing bacteria are cultured in the presence of methanol vapor as principal carbon source for sufficient time to allow adaptation to occur.

Microbiological oxidations

A process for the partial degradation of complex cyclicorganic compounds such as 1-phenylheptane and m-chlorotoluene using methane-utilizing microorganisms or enzyme extracts thereof containing the enzymes methane mono-oxygenase and/or a de-halogenase. The preferred microorganism is Methylosinus trichosporium strain OB3b (NCIB 11131).

Biotransformations using methane-utilizing bacteria

There are provided processes for carrying out enzymatic reactions, especially processes for the oxidative or reductive transformation of organic compounds catalyzed by enzymes, in which the enzymes require a continuing supply of reducing equivalents to regenerate reduced enzyme species in enzymatically active form, and in which the reducing equivalents are derived electrochemically, including electrochemically from molecular hydrogen, the reducing equivalents preferably being passed directly to the enzyme from the cathode of an electrochemical system.

Growing community of inventors

Wilden, United Kingdom

Irving J Higgins