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).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

The present disclosure provides nanoparticle transducers and methods of use thereof for the detection of analyte concentrations in a fluid. Nanoparticle transducers can comprise a nanoparticle, such as a Pdot, coupled to an enzyme that catalyzes a reaction with the analyte. The nanoparticle transducers further comprise chromophores that emit fluorescence that varies as a function of the concentration of one of the elements of the reaction. The nanoparticle transducer thus changes fluorescence as the analyte concentration changes, transforming analyte concentration values into fluorescence intensities. The measurement of these intensities provides a measurement of the analyte concentration. The nanoparticle transducers are biocompatible, allowing for use in vivo, for the monitoring of analyte blood concentrations such as blood glucose concentrations.

A method of detecting at least one analyte in a test sample is provided comprising a) contacting the test sample (i) to an active chemistry matrix changing at least one electrochemical property dependent on an enzymatic activity active in the presence of the analyte, the active chemistry matrix contacting a first electrode; and (ii) to an inactive chemistry matrix, the inactive chemistry matrix contacting a second electrode, b) closing an electrical circuit including the first electrode, the second electrode, and the active chemistry matrix and inactive chemistry matrix, followed by determining a first value of the at least one electrochemical property, c) inverting electrical polarity of the electrical circuit of b), followed by determining a second value of the at least one electrochemical property, and d) detecting the at least one analyte based on the first value and on the second value.

Provided is a method for measuring a component of a biological sample with a biosensor provided with: a capillary for introducing the biological sample; an electrode part including a first electrode system that includes a first working electrode and a first counter electrode in the capillary; and a reagent part disposed so as to be in contact with the electrode part, the reagent part containing an enzyme and a mediator, and the method including a step of starting voltage application for a duration longer than 0 second and up to 0.7 second to the first electrode system within 0 second to 0.5 second after detection of the introduction of the biological sample to obtain a hematocrit value based on a current value obtained thereby.

The invention provides amperometric analyte sensor systems comprising one or more electrodes designed to monitor in vivo levels of 3-hydroxybutyrate (and optionally glucose as well) in order to facilitate the management of diabetic ketoacidosis. The invention further includes compositions, elements and methods useful with such amperometric analyte sensor systems.

The present disclosure provides a means for preventing or suppressing the leaching of a redox mediator constituting a reagent layer in a probe of an embedded biosensor, in particular, a means capable of improving preservation stability (durability) while maintaining glucose measurement sensitivity. The high molecular weight redox polymer according to the present disclosure is represented by general formula (A1), wherein X.sup.− represents an anionic species; L represents a linker; Poly represents a high molecular weight polymer; and R.sup.1 to R.sup.8 each independently represent a hydrogen atom or a substituent. The biosensor according to the present disclosure has a working electrode, a counter electrode, a reagent layer disposed on the working electrode, and a protective film covering at least the reagent layer, and the reagent layer contains an oxidoreductase that oxidizes or dehydrogenates the analyte and at least one high molecular weight redox polymer represented by general formula (A1).

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Methods and systems are described for fabricating thin hydrogel layers on biosensors by a drop-spin method, which includes placing a drop of the hydrogel on the electrode, spinning the wafer at high speed in a vacuum, and heating the wafer to cure. One and multilayer sensors can be fabricated in this way, by adding layers of hydrogel or metal.

A biosensor component is provided that provides enhanced characteristics for use in biosensors, such as blood glucose sensors. The biosensor component comprises a substrate, a conductive layer deposited on the substrate, and a resistive material layer deposited on the conductive layer. The conductive layer includes nickel, chromium, and iron, such that a combined weight percent of the nickel and chromium in the conductive layer is in the range of 25 to less than 95 weight percent, the weight percent of nickel in the conductive layer is at least 4 weight percent, the weight percent of chromium in the conductive layer is at least 10 weight percent, the weight percent of iron in the conductive layer at least 2 weight percent, and such that the conductive layer comprises 0 to 20 weight percent molybdenum.

Systems and methods of use for continuous analyte measurement of a host's vascular system are provided. In some embodiments, a continuous glucose measurement system includes a vascular access device, a sensor and sensor electronics, the system being configured for insertion into communication with a host's circulatory system.

A biosensor component is provided that provides enhanced characteristics for use in biosensors, such as blood glucose sensors. The biosensor component comprises a substrate, a conductive layer deposited on the substrate, and a resistive material layer deposited on the conductive layer. The conductive layer includes nickel, chromium, and iron, such that a combined weight percent of the nickel and chromium in the conductive layer is in the range of 25 to less than 95 weight percent, the weight percent of nickel in the conductive layer is at least 8 weight percent, the weight percent of chromium in the conductive layer is at least 10 weight percent, the weight percent of iron in the conductive layer at least 2 weight percent, and such that the conductive layer comprises 0 to 20 weight percent molybdenum.