Abstract: NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P)+) or derivative thereof; an NAD(P)+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

Abstract: Membranes permeable to an analyte may overlay the active sensing region of a sensor to limit the analyte flux and improve the response linearity of the sensor. Temperature variation of the analyte permeability can be problematic in some instances. Polymeric membrane compositions having limited variation in analyte permeability as a function of temperature may comprise: a polymer backbone comprising one or more side chains that comprise a heterocycle; and an amine-free polyether arm appended, via an alkyl spacer or a hydroxy-functionalized alkyl spacer, to the heterocycle of at least a portion of the one or more side chains.

Abstract: Analyte sensors featuring an enzyme system comprising diaphorase and a NAD-dependent dehydrogenase may be utilized to detect inhibitors of diaphorase, provided that the transfer of electrons to a working electrode is rate-limiting with respect to the diaphorase. Such analyte sensors may comprise a sensor tail comprising at least a first working electrode, a first active area disposed upon a surface of the first working electrode, and an analyte-permeable membrane overcoating at least the first active area. The enzyme system comprises NAD, reduced NAD, or any combination thereof; a NAD-dependent dehydrogenase, such as NAD-dependent glucose dehydrogenase; and diaphorase. Inhibitors of diaphorase that may be detected include, for example, warfarin, dicoumarol, and similar compounds. A second active area may be present to facilitate detection of an analyte differing from the inhibitor of diaphorase.

Abstract: Embodiments of the present disclosure relate to NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Also provided are methods for making the compositions and for detecting and/or measuring analytes with NADP-dependent oxidoreductase compositions.

Abstract: Analyte sensors responsive at low working electrode potentials may comprise an active area upon a surface of a working electrode, wherein the active area comprises a polymer, a redox mediator covalently bonded to the polymer, and at least one analyte-responsive enzyme covalently bonded to the polymer. A specific redox mediator responsive at low potential may have a structure of wherein G is a linking group covalently bonding the redox mediator to the polymer. A mass transport limiting membrane permeable to the analyte may overcoat the active area. In some sensor configurations, the mass transport limiting membrane may comprise a membrane polymer crosslinked with a branched crosslinker comprising three or more crosslinkable groups, such as polyethylene glycol tetraglycidyl ether.

Abstract: Methods and analyte sensors including a sensor tail comprising at least a first working electrode and a second working electrode that are spaced apart from one another along a length of the sensor tail. A first active area is disposed upon a surface of the first working electrode and a second active area is disposed upon a surface of the second working electrode, the first active area and the second active area being responsive to different analytes. A mass transport limiting membrane is deposited upon the first active area and the second active area by sequential dip coating operations, and the mass transport limiting membrane comprises a bilayer membrane portion overcoating the first active area and a homogeneous membrane portion overcoating the second active area.

Abstract: Methods and analyte sensors including at least a first working electrode having a first active area thereon, and performing a dip coating operation to deposit a bilayer membrane upon the first working electrode and the first active area. The bilayer may include an inner layer having a first membrane polymer and an outer layer having a second membrane polymer, the first membrane polymer and the second membrane polymer differing from one another. The dip coating operation may comprise one or more first dips in a first membrane formulation to form the inner layer of the bilayer membrane and one or more second dips in a second membrane formulation to form the outer layer of the bilayer membrane upon the inner layer.

Abstract: Apparatus, methods, and systems for detecting alcohol concentrations of an individual, and in particular in vivo alcohol concentrations of an individual. Alcohol sensing compositions include at least one alcohol-responsive active area comprising a concerted enzyme system having at least a first enzyme and second enzyme capable of acting in concert to facilitate the detection of alcohol. At least one of the enzymes in the concerted enzyme system is a ketoreductase.

Abstract: Provided are sensors for determining the concentration of an analyte in a sample fluid. In certain embodiments, the sensors include conductive particles and exhibit improved uniformity of distribution of one or more sensing chemistry components, increased effective working electrode surface area, and/or reduced entry of interfering components into a sample chamber of the sensor. Methods of using and manufacturing the sensors are also provided.

Abstract: Creatinine levels may be monitored as a measure of kidney function. Conventionally, blood and/or urine tests are used for this purpose. Analyte sensors capable of monitoring creatinine in vivo may comprise: a sensor tail comprising at least a first working electrode, a creatinine-responsive active area disposed upon a surface of the first working electrode, a first membrane that is permeable to creatinine and overcoats the creatinine-responsive active area, and an oxygen scavenger located upon the sensor tail in proximity to the creatinine-responsive active area. The creatinine-responsive active area comprises a first electron transfer agent, a first polymer, and an enzyme system comprising multiple enzymes, particularly creatinine amidohydrolase, creatine amidohydrolase, and sarcosine oxidase, that are capable of acting in concert to facilitate detection of creatinine.

Abstract: Multiple enzymes may be present in one or more active areas of an electrochemical analyte sensor for detecting one or more different analytes. In particular, an analyte sensor may comprise a sensor tail configured for insertion into a tissue and one or more working electrodes having a glucose-responsive active area and an ethanol-responsive active area to detect glucose and ethanol in vivo.

Abstract: Multiple enzymes may be present in the active area(s) of an electrochemical sensor to facilitate analysis of one or more analytes. The multiple enzymes may function independently to detect several analytes or in concert to detect a single analyte. One sensor configuration includes a first active area and a second active area, where the first active area has an oxidation-reduction potential that is sufficiently separated from the oxidation-reduction potential of the second active area to allow independent signal production. Some sensor configurations may have an active area overcoated with a multi-component membrane containing two or more different membrane polymers. Sensor configurations having multiple enzymes capable of interacting in concert include those in which a first enzyme converts an analyte into a first product and a second enzyme converts the first product into a second product, thereby generating a signal at a working electrode that is proportional to the analyte concentration.

Abstract: Generally, embodiments of the invention relate to self-powered analyte determining devices (e.g., electrochemical analyte monitoring systems) that include a working electrode, a counter electrode, and an optional resistance value, where the working electrode includes analyte sensing components and the self-powered analyte determining device spontaneously passes a current directly proportional to analyte concentration in the absence of an external power source. Also provided are systems and methods of using the, for example electrochemical, analyte sensors in analyte monitoring.

Abstract: A lactate-responsive enzyme may form the basis for lactate detection and quantification using an electrochemical analyte sensor. Various features may be incorporated within an analyte sensor containing a lactate-responsive enzyme, particularly lactate oxidase, to improve sensitivity and response stability of the analyte sensor. Such analyte sensors may comprise: a working electrode having an active area disposed thereon, and a mass transport limiting membrane overcoating at least the active area upon the working electrode. The active area comprises at least a polymer, an albumin, and a lactate-responsive enzyme that is covalently bonded to the polymer. The mass transport limiting membrane may comprise at least a crosslinked polyvinylpyridine homopolymer or copolymer. The analyte sensors may determine a lactate concentration in a biological fluid, particularly in vivo, which may be correlated to various physiological conditions.

Abstract: Enzyme compositions including lactate responsive enzyme and stabilizing agent, including electrodes, sensors, and systems having the same. The stabilizing agent stabilizes the lactate responsive enzyme in a manner sufficient to increase sensitivity to lactate, such as for use in in vivo detection of lactate. In some compositions the lactate responsive enzyme is lactate oxidase and the sensor includes a heterocycle-containing polymer and a crosslinker.

Abstract: An analyte sensor including an antiglycolytic agent or a precursor thereof and a chelating agent that stabilizes the antiglycolytic agent positioned proximate to the working electrode of the sensor. Also provided are systems and methods of using the electrochemical analyte sensors in analyte monitoring.

Abstract: An analyte sensor including an antiglycolytic agent or a precursor thereof and a chelating agent that stabilizes the antiglycolytic agent positioned proximate to the working electrode of the sensor. Also provided are systems and methods of using the electrochemical analyte sensors in analyte monitoring.

Abstract: Embodiments of the present disclosure relate to NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Also provided are methods for making the compositions and for detecting and/or measuring analytes with NADP-dependent oxidoreductase compositions.

Abstract: Generally, embodiments of the invention relate to self-powered analyte determining devices (e.g., electrochemical analyte monitoring systems) that include a working electrode, a counter electrode, and an optional resistance value, where the working electrode includes analyte sensing components and the self-powered analyte determining device spontaneously passes a current directly proportional to analyte concentration in the absence of an external power source. Also provided are systems and methods of using the, for example electrochemical, analyte sensors in analyte monitoring.

Abstract: Embodiments of the present disclosure relate to analyte determining methods and devices (e.g., electrochemical analyte monitoring systems) that have a membrane structure with an analyte permeability that is substantially temperature independent. The devices also include a sensing layer disposed on a working electrode of in vivo analyte sensors, e.g., continuous and/or automatic in vivo monitoring using analyte sensors and/or test strips. Also provided are systems and methods of using the, for example electrochemical, analyte sensors in analyte monitoring.