Devices, patch sensors, and methods for detecting a ketone body are disclosed. An exemplary device includes a collection apparatus for collecting a sample amount of interstitial fluid and a ketone body indicator having an initial negative state and having a positive state when at least a threshold value of the ketone body is collected in the sample amount.

The present invention relates to a mutant 3-hydroxybutyrate dehydrogenase (3-HBDH) with improved performance relative to the wild-type 3-HBDH, a nucleic acid encoding the mutant 3-HBDH, a cell comprising the mutant 3-HBDH or the nucleic acid, a method of determining the amount or concentration of 3-hydroxybutyrate in a sample, and a device for determining the amount or concentration of 3-hydroxybutyrate in a sample.

A butanol expression cassette includes a butanol production related genes and a fermentation regulatory element. The fermentation regulatory element controls the expression of the butanol production related gene and locates upstream of the butanol production related gene. The fermentation regulatory element includes a promoter, a ribosome binding site and a transcription factor binding site of a fermentation gene. A fermentation in which the fermentation regulatory element involves includes an acetic acid fermentation, an alcohol fermentation, a succinic acid fermentation or a lactic acid fermentation, the butanol production related gene is not the fermentation gene or a gene of an upstream product of the fermentation in which the fermentation gene involves. The present invention provides a recombinant plasmid formed by cloning the butanol expression cassettes in the expression vector. The present invention also provides a butanol production related gene expression method to express butanol production related gene by using recombinant plasmid.

The present disclosure relates to a mutant 3-hydroxybutyrate dehydrogenase (3-HBDH) with improved performance relative to the wild-type 3-HBDH, a nucleic acid encoding the mutant 3-HBDH, a cell having the mutant 3-HBDH or the nucleic acid, and/or a method of determining the amount or concentration of 3-hydroxybutyrate in a sample. Also disclosed is the use of the mutant 3-HBDH for determining the amount or concentration of 3-hydroxybutyrate in a sample, and a device for determining the amount or concentration of 3-hydroxybutyrate in a sample.

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.

Briefly, a sensor for a continuous biological monitor is provided that has a working electrode with a new interfere layer that is (1) non-electron conducting, (2) ion passing, and (3) permselective for molecular weight. The new interference layer is made by mixing a monomer and a mildly basic buffer, and then electropolymerizing the monomer and the buffer into a polymer. The polymer is deposited onto a working electrode for a continuous metabolic monitor, for example, using an electro depositing process in the form of cyclic voltammety (CV). The interference layer is permselectable for molecule size by adjusting the pH of the basic buffer.

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.

Briefly, a sensor for a continuous biological monitor is provided that has a working electrode with a new interfere layer that is (1) non-electron conducting, (2) ion passing, and (3) permselective for molecular weight. The new interference layer is made by mixing a monomer and a mildly basic buffer, and then electropolymerizing the monomer and the buffer into a polymer. The polymer is deposited onto a working electrode for a continuous metabolic monitor, for example, using an electro depositing process in the form of cyclic voltammety (CV). The interference layer is permselectable for molecule size by adjusting the pH of the basic buffer.

Briefly, a sensor for a continuous biological monitor is provided that has a working electrode with an enhanced 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 is added to the base emulsion, which is applied to the working electrode and cured. Optionally, other additives can be added to the base emulsion prior to application, such as hydrophiles, cross linkers, adding imodeoesters, hydroxysuccimide, carboldilite, melamines, epoxies, benzoyl peroxide or dicumyl peroxide.

Briefly, a carbon working electrode is described that has a plastic substrate of polyethylene, polypropylene, polystyrene, polyvinyl chloride, or polylactic acid, and may be formed into an elongated wire. The carbon material coats the plastic substrate, and may be, for example, graphene, diamagnetic graphite, pyrolytic graphite, pyrolytic carbon, carbon black, carbon paste, or carbon ink, which is aqueously dispersed in an elastomeric material such as polyurethane, silicone, acrylates or acrylics. Optionally, selected additives may be added to the carbon compound prior to it being layered onto the plastic substrate. These additives may, for example, improve electrical conductivity or sensitivity, or act as a catalyst for target analyte molecules.