Enhanced sensor for a continuous biological monitor

Inventors

Boock, Robert James • Zhang, Huashi

Assignees

Allez Health Inc

Abstract

Briefly, a sensor for a continuous biological monitor is provided for measuring the level of a target analyte for a patient. The sensor has a working wire and a reference wire, where the working wire has an analyte limiting layer that passes more than 1 in 1000 analyte molecules from the patient to the an enzyme layer. The enzyme layer has an enzyme entrapped in a polyurethane cross-linked with acrylic polyol. As free electrons are generated, a conductor transfers the electrons to the biological monitor. In some cases, the sensor may be constructed without the use of any expensive platinum.

Core Innovation

The disclosed invention relates to a sensor for a continuous glucose monitor that is subcutaneously inserted into a patient, including a reference electrode and a working electrode. The working electrode includes a glucose limiting layer with hydrophobic bonding material and hydrophilic bonding material that are physically cross-linked, and the glucose limiting layer controls the passage of glucose by hydrogen bonding.

The sensor further includes an enzyme layer comprising glucose oxidase entrapped within a polyurethane that is cross-linked with a self cross-linking acrylic polyol. The glucose oxidase reacts with glucose in blood of the patient to generate peroxide and free electrons in proportion to a glucose level in the blood of the patient, and a conductor is configured to pass the free electrons to the continuous glucose monitor for measurement.

The disclosure also describes a sensor architecture that supports direct electron/free-electron generation associated with the peroxide interaction in carbon-enzyme layers, reducing reliance on expensive platinum. The sensor can include an interference membrane or interference layer positioned between an enzyme layer and a glucose limiting layer, where the interference layer is non-electron-conducting and ion-passing and is permselective by molecular weight via PoAP electrodeposition with a pH-tunable cutoff.

Additionally, the patent describes applying hydrogen-bonding-controlled glucose flux for improved linearity and calibration, and it describes improved enzyme-layer distribution and entrapment using aqueous polyurethane and self-crosslinking acrylic polyol rather than glutaraldehyde-stabilized layers.

Claims Coverage

The patent includes two independent claims directed to subcutaneously inserted sensors for continuous monitoring, one explicitly for continuous glucose monitoring and one for continuous biological monitoring. Each independent claim specifies a shared inventive architecture with a reference electrode, a working electrode, a physically cross-linked limiting layer using hydrophobic and hydrophilic bonding materials, an enzyme entrapped in polyurethane cross-linked with a self cross-linking acrylic polyol, generation of peroxide and free electrons proportional to a glucose level, and a conductor configured to pass the free electrons to a continuous monitor for measurement.

Across the independent claims, the core claimed coverage is the subcutaneous sensor architecture that generates free electrons proportional to a glucose level via an enzyme layer made of enzyme entrapped in polyurethane cross-linked with a self cross-linking acrylic polyol, together with a physically cross-linked limiting layer using hydrophobic and hydrophilic bonding materials and a conductor configured to pass the free electrons to a continuous monitor for measurement. Dependent claims further cover an interference layer with defined molecular weight permselectivity and hydrogen-bonding-controlled glucose flux.

Stated Advantages

Documented Applications