Sensor for components of a liquid mixture
First Claim
1. A sensor electrode for use in a liquid mixture of components, said electrode being responsive to the presence of at least one selected component of said mixture capable of undergoing an enzyme-catalysed reaction, the electrode being composed of electrically conductive material and comprising, at least at an external surface thereof, the combination of an enzyme and a mediator comprising a ferrocene which transfer electrons between the enzyme and the conductive material of the electrode when the enzyme is catalytically active to provide a current representative of said activity.
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Abstract
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.
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Citations
19 Claims
- 1. A sensor electrode for use in a liquid mixture of components, said electrode being responsive to the presence of at least one selected component of said mixture capable of undergoing an enzyme-catalysed reaction, the electrode being composed of electrically conductive material and comprising, at least at an external surface thereof, the combination of an enzyme and a mediator comprising a ferrocene which transfer electrons between the enzyme and the conductive material of the electrode when the enzyme is catalytically active to provide a current representative of said activity.
- 14. A sensor electrode for use in a liquid mixture including glucose, to provide a current representative of the presence of glucose therein, the electrode consisting essentially of solid carbon, a layer of ferrocene-type compound at an external surface thereof as an electron-transferring mediator, and an enzyme which is glucose oxidase or bacterial glucose dehydrogenase located upon said mediator layer.
- 18. A sensor suitable for implantation comprising a sensor electrode and means for implantation of said sensor electrode in a human subject, said sensor electrode being responsive to the presence in said subject of at least one selected component capable of undergoing an enzyme-catalyzed reaction, said electrode being composed of electrically conductive material and comprising, at least at an external surface thereof, the combination of an enzyme, and a mediator comprising a ferrocene which transfers electrons between the enzyme and the conductive material of the electrode when the enzyme is catalytically active to provide a current representative of said activity.
Specification