Enhanced carbon-enzyme membrane for a working electrode of a continuous biological sensor

Inventors

Boock, Robert James • Zhang, Huashi

Assignees

Allez Health Inc

Abstract

Briefly, a sensor for a continuous biological monitor is provided that has a working electrode with an enhanced carbon-enzyme layer that in one embodiment is made by mixing an aqueous polyurethane emulsion with an acrylic polyol emulsion to make a base emulsion. An enzyme and carbon materials are added to the base emulsion, which is applied to the working electrode and cured. The carbon materials may include carbon and graphite to provide strength, as well as graphene or pyrolytic graphite to provide a desirable electrical resistance for the carbon-enzyme layer. Optionally, other additives can be added to the base emulsion prior to application, such as hydophiles, cross linkers, adding imodeoesters, hydroxysuccimide, carboldilite, melamines, epoxies, benzoyl peroxide or dicumyl peroxide.

Core Innovation

The disclosed invention relates to continuous glucose monitoring sensor architectures using a carbon-containing, elastomer-bound layer on a plastic substrate and a platinum-free working electrode. A continuous biological monitor electrode system is described with a working electrode and associated electrodes, where the working electrode includes an electrically conductive carbon-enzyme layer that responds to reacting an enzyme with a target biologic.

A carbon-enzyme layer is formed from a polyurethane emulsion and an acrylic polyol emulsion that are mixed to make a base emulsion, then an enzyme selected according to the biological function to be monitored and a carbon material are added to the base emulsion. The applied base emulsion is cured to form the carbon-enzyme layer, which facilitates generation of either peroxide or electrons within the carbon-enzyme layer responsive to the enzyme reaction with the target biologic.

The invention further includes concepts of regulating hydrogen peroxide flux and forming a glucose limiting layer, including an interference membrane that is non-electron-conducting, ion-passing, and permselective, and a glucose limiting layer formed by physically cross-linked hydrogen-bonded hydrophilic/hydrophobic bonding gels without chemical cross-linking. The enzyme layer uses aqueous polyurethane emulsion and acrylic polyol emulsion components configured to self-crosslink to entrap GOx and provide improved even dispersion and safety, enabling platinum-free operation while supporting stability, linearity, and signal-to-noise.

Claims Coverage

The partial content includes two independent method claims covering manufacture of a carbon-enzyme layer on a working electrode of a continuous biological monitor. The claims identify three inventive features centered on a base emulsion system, incorporation of an enzyme and carbon material, and formation of an electrically conductive layer that facilitates peroxide or electron generation responsive to enzyme reaction with a target biologic.

Across both independent claims, the inventive scope centers on forming a carbon-enzyme layer by mixing an emulsion system, incorporating an enzyme selected for the biological function to be monitored, incorporating a carbon material, applying the mixture to a working electrode, and curing to obtain an electrically conductive layer that facilitates peroxide or electron generation responsive to enzyme reaction with a target biologic.

Stated Advantages

Documented Applications