Abstract: Devices and methods for determining the concentration of an analyte in a sample of liquid are provided.

Abstract: Nanosensors for detecting analytes and methods of detecting analytes have been developed in which the redox potential of a redox effector in solution is altered thereby causing changes in carbon nanotube conductance. The analyte may be detected in solution, eliminating the need for immobilizing the analyte on a support.

Abstract: The present invention generally relates to a system and method that co-locates in a small flexible, configurable system and multi-level substrate sampling, rapid analysis, bio-sample storage and delivery functions to be performed on living tissues or matter obtained from living organisms. The types of the sampling may include chemical, biochemical, biological, thermal, mechanical, electrical, magnetic and optical sampling. In general, the analysis performed at the point of sampling measures the sample taken and records its value. The bio-sample storage function encapsulates a small sample of analyte and preserves it for subsequent examination or analysis, either on the organism by the system or at a remote location by an independent analysis system. Once stored, the sample can provide a record of a biological state at the precise time of sampling. The delivery at the point of sampling can include chemical, biochemical, thermal, mechanical, electrical, magnetic and optical stimuli.

Abstract: A sensor of pyrophosphate which can detect pyrophosphate conveniently with high sensitivity in a method for measuring pyrophosphate in SNP typing utilizing a primer extension reaction is provided. A sensor of pyrophosphate which is characterized by including: an insulative substrate 1; an electrode system that is formed thereon and has a measurement electrode 2 and a counter electrode 3; and a plurality of reaction reagent layers that are provided on the substrate 1 and include pyrophosphatase, glyceraldehyde-3-phosphate dehydrogenase, diaphorase, glyceraldehyde-3-phosphate, oxidized nicotineamide adenine dinucleotide, an electronic mediator, a magnesium salt and a buffer component, reaction reagent layer 36 including the enzyme being separated from reaction reagent layer 35 including the buffer component, and reaction reagent layer 37 including glyceraldehyde-3-phosphate being separated from the reaction reagent layer 35 including the buffer component.

Abstract: The present application provides Ag/AgCl based reference electrodes having an extended lifetime that are suitable for use in long term amperometric sensors. Electrochemical sensors equipped with reference electrodes described herein demonstrate considerable stability and extended lifetime in a variety of conditions.

Abstract: A rapid electrochemical flow-through sensor and method for detecting the presence of autoantibodies in a fluid sample such as blood is shown and described. The sensor may take either a single- or multi-plexed form. The sensor comprises a fluid inlet, a reaction region comprising immobilized autoantigens and an electrode assembly, and a fluid outlet.

Abstract: Silver-coated proteins, being dissolvable or suspendable in aqueous media and/or retaining a biological activity of the protein and a process for preparing same are disclosed. Further disclosed are modified proteins which have a reducing moiety attached to the surface thereof and a process for preparing same. The modified proteins can be utilized for obtaining the silver-coated proteins. Further disclosed are a pharmaceutical composition containing and a method of treating bacterial and fungal infections utilizing biologically active silver-coated hydrogen peroxide producing enzymes such as glucose oxidase. Further disclosed are conductive elements that comprise the silver-coated proteins disclosed herein and electronic circuits containing same. Further disclosed are electrodes having the silver-coated proteins deposited thereon and biosensor systems utilizing same for determining a level of an analyte in a liquid sample.

Abstract: An electrochemical test sensor and method for forming the same for determining the concentration of an analyte in a fluid sample includes a base, a reagent layer, a lid, and a meter contact area that has a plurality of contacts. The meter contacts have a first testing contact, a second testing contact, and at least four coding contacts. At least a first electrical connection forms between the first testing contact and a first one of the plurality of coding contacts. At least a second electrical connection forms between the second testing contact and a second one of the plurality of coding contacts. A plurality of electrical connections forms or are severed between the plurality of adjacent coding contacts. At least one of the connections in the meter contact area is terminated or formed to encode calibration information on the test sensor.

Abstract: The present invention relates to a method for fabricating a pattern on a biosensor substrate and a biosensor using the same. The present invention provides a method of fabricating a pattern on a substrate of a biosensor in which an amine group is formed on a substrate by using polyethylenimine (PEI), and a site to which a biosubstance is immobilized is masked and irradiated with ultraviolet rays, such that a pattern having a desired shape can be formed on the substrate and a biosensor in which the biosubstance is immobilized on the pattern acquired by using the above-mentioned method.

Abstract: The present invention is directed to a method of reducing the effects of interfering compounds in the measurement of analytes and more particularly to a method of reducing the effects of interfering compounds in a system wherein the test strip utilizes two or more working electrodes. In one embodiment of the present invention, a first potential is applied to a first working electrode and a second potential, having the same polarity but a greater magnitude than the first potential, is applied to a second working electrode.

Abstract: An electrochemical test sensor is adapted to measure glucose and correct for the oxygen effect in a fluid sample. The test sensor comprises a base, first and second working electrodes, and a counter electrode. The first working electrode includes glucose oxidase, a mediator and peroxidase. The second working electrode includes glucose oxidase and the mediator. The first working electrode, the second working electrode and the counter electrode are located on the base. In other embodiments, an electrochemical test sensor is adapted to measure cholesterol, lactate, pyruvate or xanthine and correct for the oxygen effect in a fluid sample.

Abstract: This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

Abstract: The disclosure provides for reagent compositions for biosensors comprising release polymers, methods of making such biosensors and films of reagent compositions comprising release polymers. The reagent compositions comprise a release polymer and an effective analyte detecting amount of an enzyme an enzyme cofactor and a redox compound capable of acting in a biosensor as (i) a redox mediator associated with a working electrode (ii) a redox couple associated with a reference electrode or (iii) the redox mediator associated with the working electrode and the redox couple for the reference electrode.

Abstract: Disclosed are a tyrosinase enzyme electrode containing metal nanoparticles and its producing method. Metal nanoparticles are applied to a surface of a support with high chemical stability. Also, a buffer layer consisting of a self-assembled monolayer is formed on the metal nanoparticles. Such self-assembled monolayer is used to immobilize tyrosinase enzyme which was subsequently prepared. In other words, the self-assembled monolayer is arranged between the metal nanoparticles and the tyrosinase enzyme so as to immobilize the tyrosinase enzyme on the support. Introduction of the metal nanoparticles into the electrode contributes to improvement in detection limits of the tyrosinase enzyme electrode. In addition, the introduction of substrate induces the activation of enzyme.

Abstract: 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.

Abstract: The present invention provides an apparatus for measuring activity signals of a biological sample comprising: a measurement chamber (A) storing a target liquid containing a biological sample; a porous insulating substrate (5) provided with a measurement electrode (1) on at least one side; and a conveying device (8) which conveys the target liquid stored in the measurement chamber (A) and passes the target liquid through the porous insulating substrate (5) from the measurement electrode (1) side, wherein the conveying device (8) is operated to trap the biological sample contained in the target liquid onto the measurement electrode (1), so that the activity signals of the biological sample are measured through the measurement electrode (1). According to the apparatus, activity signals emitted from the biological sample can be detected easily, rapidly and accurately.

Abstract: It is an object of the present invention to provide a sensor, which is capable of measuring, quickly and in high accuracy, concentration of neutral fat from a sample such as a biological sample or the like, without executing pretreatment of the sample. This object is attained by a biosensor for measuring concentration of neutral fat, based on value of current flowing in the electrode system, having: an insulating substrate; an electrode system having a working electrode and a counter electrode, formed onto the insulating substrate; and a reaction layer having a lipoprotein lipase, a glycerol dehydrogenase and an electron mediator, formed at the upper part or the vicinity of the electrode system.

Abstract: Methods and devices for determining factor Xa inhibitors, in particular heparins and fractionated or low-molecular-weight heparins, as well as direct factor Xa inhibitors in blood samples. The methods include contacting a blood sample with a detection reagent that contains at least one thrombin substrate having a peptide residue that can be cleaved by thrombin and is amidically bound via the carboxyl end to an electrogenic substance, and with a known amount of factor X reagent and an activator reagent which induces the conversion of factor X into factor Xa. Subsequently, in a second step, the amount or activity of the electrogenic substance that is cleaved from the thrombin substrate by the factor Xa-mediated thrombin activation and/or the time course thereof is determined as the measurement signal using electrochemical methods.

Abstract: An enzymatic electrochemical-based sensor includes a substrate and a conductive layer formed from a dried water-miscible conductive ink. The water-miscible conductive ink used to form the conductive layer includes a conductive material, an enzyme, a mediator, and a binding agent and is formulated such that the water-miscible conductive ink is a water-miscible aqueous-based dispersion and the binding agent became operatively water-insoluble upon drying.

Abstract: The present invention provides a chip 100 that enables an immunoassay with high accuracy and without requiring a high volatile reagent. The chip 100 includes a chip substrate 20, a reagent mixture 12 and potassium ferricyanide 11 that are immobilized leaving a space in between on the chip substrate 20. The reagent mixture 12 includes at least one selected from NADP and NADPH, malate dehydrogenase, and a substrate of malate dehydrogenase. The chip 100 further includes diaphorase, immobilized on the chip substrate 20, as a part of or a component other than the reagent mixture 12.

Abstract: An electrochemical cell for detection and quantification of analytes in a liquid sample, particularly a liquid sample having a small volume. In a preferred embodiment, the electrochemical cell comprises an assembly of conducting layers and insulating layers. The electrochemical cell can be formed by depositing conducting materials and insulating materials in alternating layers on an insulating substrate. It is preferred that the layer furthest from the insulating substrate be an insulating layer to minimize the damage of the conducting layers during handling of the electrochemical cell. A passage can be formed through the conducting layers and the insulating layers to expose the edges of the layers, which collectively form the wall or walls of the passage. The exposed edges of the conducting layers form the electrodes of the electrochemical cell. The electrochemical cell comprises at least one working electrode and at least one other electrode, e.g., a dual-purpose reference/counter electrode.

Abstract: Embodiments of the invention provide analyte sensors having nanostructured electrodes as well as methods for making and using such sensors. In certain embodiments of the invention, the sensor includes a carbon nanotube electrode and a analyte limiting membrane that modulates the ability of a analyte to contact the carbon nanotube electrode.

Abstract: The present invention discloses a potentiometric biosensor for detecting creatinine, and the forming method thereof. The disclosed biosensor comprises a substrate, a working electrode formed on the substrate, a first reference electrode formed on the substrate, a second reference electrode formed on the substrate, and a packaging structure which separates the above-mentioned three electrodes. The working electrode comprises creatinine iminohydrolase (CIH). The detection signal is transmitted out from the biosensor for further processing through a wire or an exposed surface. The disclosed biosensor is replaceable.

Abstract: A method for determining a concentration of an analyte is disclosed. The method includes applying a potential excitation to a fluid sample containing an analyte and determining if a current decay curve associated with the fluid sample has entered an analyte depletion stage. The method also includes measuring a plurality of current values associated with the fluid sample during the analyte depletion stage and calculating an analyte concentration based on at least one of the plurality of current values.

Abstract: A method for the determination of the amount of cholesterol in lipoproteins other than high density lipoproteins in a lipoprotein-containing sample, said method comprising (a) electrochemically determining the amount of cholesterol bound to high density lipoproteins in the sample, (b) electrochemically determining the total amount of cholesterol in the sample, and subtracting the result of (a) from the result of (b).

Abstract: Biological reagent compositions with improved sensitivity to the concentration of blood glucose in patient samples for use in measuring systems and methods. The reagent compositions comprise a glucose oxidoreductase enzyme, a flavin nucleoside coenzyme and a mediator formulation. The mediator formulation comprises at least one electroactive organic molecule and at least one coordination complex.

Abstract: An electrically non-conductive, nanoparticulate membrane comprising nanoparticles of at least one inorganic oxide of an element selected from Group IA, IIA, IIIA, IVA, IB, IIB, IIIB, IVAB, VB, VIB, VIIB or VIIIB of the Periodic Table, and wherein an oxidoreductase enzyme and a polymeric redox mediator capable of transferring electrons are diffusibly dispersed in said nanoparticulate membrane.

Abstract: A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and/or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

Abstract: A reagent composition for a biosensor sensor strip is disclosed that provides for rapid rehydration after drying. The composition includes porous particles and is preferably formed as a colloidal suspension. The dried reagent composition including porous particles may provide analytically useful output from the sensor strip in a shorter time period than observed from dried reagent compositions using solid particles. The output signal from the porous particle compositions may be correlated to the analyte concentration of a sample within about two seconds. In this manner, an accurate concentration determination of an analyte concentration in a sample may be obtained in less time than from sensor strips including conventional compositions. The reagent composition including the porous particles also may allow for the redox reaction between the reagents and the analyte to reach a maximum kinetic performance in a shorter time period than observed from conventional sensor strips.

Abstract: The present invention relates to a glucose sensor (2) including an electrode (32) which includes a conductive component and glucose dehydrogenase immobilized to the conductive component. As the glucose dehydrogenase, use is made of a protein complex including a catalytic activity subunit which has glucose dehydrogenase activity, and an electron mediator subunit for supplying an electron donated from the catalytic activity subunit to the conductive component. Preferably, the glucose sensor (2) is designed to continuously measure the glucose level or successively measure the glucose level a plurality of times.

Abstract: Disclosed is a DNA analysis method and a DNA analyzer whose signal intensity is not lowered even when a material at a higher density is measured. There is supplied dATP, dTTP, dGTP, or dCTP from a dATP solution vessel, a dTTP solution vessel, a dGTP solution vessel, or a dCTP solution vessel, and this causes an extension reaction of a double-stranded DNA immobilized to a bead, to yield pyrophosphoric acid. The pyrophosphoric acid is converted into a redox compound by the actions of a reagent and an enzyme contained in a reaction buffer in a reaction buffer vessel. The redox compound causes a variation in surface potential of a measuring electrode bearing an electrochemically active material immobilized thereto through an insulating molecule, and this variation causes a variation in drain current of a field-effect transistor electrically connected to the measuring electrode. Thus, the extension reaction is detected.

Abstract: A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and/or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

Abstract: An embodiment of the invention provides an ultrasensitive and selective system and method for detecting reactants of the chemical reaction catalyzed by an oxidoreductase, such as glucose and ethanol, at a concentration level down to zepto molar (10?21 M). In embodiments, the invention provides a cyclic voltammetry system comprising a working electrode, an oxidoreductase, and an electric field generator, wherein the oxidoreductase is immobilized on the working electrode; and the electric field generator generates an electric field that permeates at least a portion of the interface between the oxidoreductase and the working electrode. The ultrasensitivity of the system and method is believed to be caused by that the electrical field enhances quantum mechanical tunneling effect in the interface, and therefore facilitates the interfacial electron transfer between the oxidoreductase and the working electrode.

Abstract: Provided are a biosensor chip measurement machine that can obtain accurate measurement results within a short period of time by employing only a tiny amount as a sample, and a measurement method therefor. A biosensor measurement machine 20 includes a power source 21, which is connected to a voltage regulator 22, a measurement instrument 23, and a controller 24 for supplying power. When a biosensor chip 1 is connected to the biosensor measurement machine 20 and a voltage is applied, the measurement instrument begins the measurement of a current value for a biosensor. When a measured current value or a measured charge value is greater than a reference value, the measurement is ended in accordance with an instruction issued by the controller 24, and when the value is smaller than the reference value, the measurement is continued in accordance with a controller instruction.

Abstract: There is provided a biosensor capable of increasing a detecting sensitivity of a target substance of glutamate, by using a nano wire having excellent electrical characteristics and by immobilizing a receptor of glutamate to be detected on a substrate which is disposed between a nano wire and another nano wire and a method for manufacturing the same. The biosensor for detecting glutamate according to the present invention can be manufactured with an arrangement in which the nano wire is selectively arranged on a solid substrate in a matrix. Since this biosensor can prevent the degradation of the nano wire in the electrical characteristic, it can sensitively detect glutamate even through a small amount thereof is contained in a food so that it can be effectively used in detecting the food additive existing in the processed foodstuffs.

Abstract: A biosensor according to the present invention comprises a support 1, a conductive layer 2 composed of an electrical conductive material such as noble metal, for example gold, palladium or the like, and carbon, slits 3a and 3b parallel to the side of the support 1, slits 4a and 4b vertical to the side of the support 1, a working electrode 5, a counter electrode 6, a detecting electrode 7, a spacer 8 which covers the working electrode 5, the counter electrode 6 and the detecting electrode 7 on the support 1, a rectangular cutout part 9 forming a specimen supply path, an inlet 9a of the specimen supply path, a reagent layer 12 formed by applying a reagent including an enzyme or the like to the working electrode 5, the counter electrode 6 and the detecting electrode 7, which is exposed from the cutout part 9 of the spacer 8, and a cover 13 which covers the spacer 8, as shown in FIG. 1.

Abstract: A method of depositing reagent on an electrochemical test sensor adapted to determine information relating to an analyte includes providing a base and forming an electrode pattern on the base. The method further includes depositing the reagent on at least the electrode pattern using a reagent-dispensing system. The reagent-dispensing system applies mechanical force to the reagent in the reagent-dispensing system to assist in providing a wet reagent droplet on at least the electrode pattern.

Abstract: An electrochemical test sensor includes a base, a generally hard electrically-conductive layer, an electrochemically-active layer, and a lid. The electrically-conductive layer is located between the base and the electrochemically-active layer. The electrically-conductive layer and the electrochemically-active layer are made of a different material. The electrically-conductive layer and the electrochemically-active layer form an electrode pattern. The electrochemical test sensor includes a reagent adapted to assist in determining information related to an analyte of a fluid sample.

Abstract: A reagent for detecting an analyte comprises a flavoprotein enzyme, a mediator such as a phenothiazine mediator, at least one surfactant, a polymer and a buffer. The reagent may be used with an electrochemical test sensor that includes a plurality of electrodes.

Abstract: Novel transition metal complexes of iron, cobalt, ruthenium, osmium, and vanadium are described. The transition metal complexes can be used as redox mediators in enzyme based electrochemical sensors. In such instances, transition metal complexes accept electrons from, or transfer electrons to, enzymes at a high rate and also exchange electrons rapidly with the sensor. The transition metal complexes include at least one substituted or unsubstituted biimidazole ligand and may further include a second substituted or unsubstituted biimidazole ligand or a substituted or unsubstituted bipyridine or pyridylimidazole ligand. Transition metal complexes attached to polymeric backbones are also described.

Abstract: Sensors for the electro-chemical analysis of samples and methods for the manufacturing of sensors allow for more efficient manufacture and use of electro-chemical sensors. Flexible sheets, such as polycarbonate sheets, are used to easily manufacture sensor components, with sensor chemistry being applied to the sensor components at manufacture. Sensors may be manufactured with modular components, enabling easy production-line manufacture and construction of electro-chemical sensors with significant cost savings and increased efficiency over existing sensor styles and sensor manufacturing techniques.

Abstract: An object of the present invention is to provide a highly functional mediator capable of smoothly proceeding electron transfer between an electrode and a biocatalyst based on the premise that the mediator excels in safety and cost and to provide an electrode and a cell with sufficient amount of such a mediator molecule immobilized efficiently and strongly. The present invention provides a mediator mediating electron transfer between an enzyme and an electrode and containing a quinone molecule derivative, in particular, a mediator containing a VK3 derivative. In addition, the present invention provides an electrode and a biofuel cell to which those mediators are applied.

Abstract: A BUN (blood urea nitrogen) sensor containing immobilized carbonic anhydrase and immobilized urease for the in vitro detection of urea nitrogen in blood and biological samples with improved performance and precision characteristics.

Abstract: The present invention is to reduce a false signal in an apparatus for electrochemically decoding a base sequence of DNA, which false signal is caused by a phenomenon that even unreacted nucleotide 5?-triphosphate derivatives remaining in the solution are electrochemically converted on an electrode.

Abstract: A small diameter flexible electrode designed for subcutaneous in vivo amperometric monitoring of glucose is described. The electrode is designed to allow “one-point” in vivo calibration, i.e., to have zero output current at zero glucose concentration, even in the presence of other electroreactive species of serum or blood. The electrode is preferably layered, with the layers serially deposited within a recess upon the tip of a polyamide insulated gold wire. A first glucose concentration-to-current transducing layer can be overcoated with an electrically insulating and glucose flux limiting layer (second layer) on which, optionally, an immobilized interference-eliminating horseradish peroxidase based film is deposited. An outer layer is preferably biocompatible.

Abstract: In a biosensor of the present invention, BSA is contained in a reagent layer including a reagent which reacts specifically with glucose, and the glucose concentration in whole blood as a sample solution is electrochemically measured. When the sensor response characteristics when whole blood is used as the sample solution are measured, the influence by hematocrit to the sensor response characteristics is reduced according to the additive amount of BSA when the hematocrit value is in the range of 25% and below, while no BSA addition effect is recognized in the sensor response characteristics when the hematocrit value is in the range of 25 to 65%. Thereby, the influences by hematocrit and temperature can be reduced, and thus highly precise measurement can be performed.

Abstract: A chemical composite useful for preparing a bioelectronic device includes a biologically active compound, such as an enzyme, that is bound directly or indirectly to a polyelectrolye, which can be reversibly coupled to a chemically treated electrically conductive substrate by electrostatic forces to provide biomimetic sensors, catalyst systems, and other devices having an electrode that can be regenerated and reused. Required or desired cofactors, mediators or the like may be incorporated into the devices, typically by bonding them to the treated substrate and/or the polyelectrolyte.

Abstract: The present invention provides a polymer membrane enhanced with cured epoxy resin for use as the outer membrane of biosensors. The membrane includes approximately 30-80% epoxy resin adhesives, 10-60% polymer such as poly(vinyl chloride), polycarbonate and polyurethane and 0-30% plasticizers and 5-15% surface modifier reagent such as polyethylene oxide-containing block copolymers. Utilizing the polymer membrane of the present invention, a three-layered sensing element has been developed. This sensing element will be particularly useful for miniaturized biosensors used for in vitro blood measurements or for continuous in vivo monitoring such as implantable biosensors. This element includes an enzyme layer, an interference-eliminating layer and the novel polymer member of the present invention as the outer polymer layer. This novel sensing element shows excellent response characteristics in solutions and has an extremely long lifetime.

Abstract: A device for detecting methanol concentration in an alcohol-containing solution is disclosed. The device implements an electrochemical bio-detector based on a two-enzyme system to quickly, easily and accurately measure methanol concentration in an alcohol-containing solution at a relatively low cost. A method for detecting methanol concentration in a sample using the same device is also disclosed.

Abstract: An assay system is provided of great sensitivity and portability where the presence of a specific target in a sample, as well as its concentration (qualification and quantification) is detected by reason of a potential or voltage in a closed circuit, built up a redox reaction. The reaction is produced by binding a capture moiety to an enzymatic redox reaction partner, allowing the capture moiety to bind to any target in the sample. In a homogenous assay, the method further comprises washing any such bound target. The bound target may be immobilized through use of a second capture moiety. Substrate for the enzyme is then added. The action on the substrate by the enzyme generates electrons, creating a potential across an anode and cathode which may be separated by a membrane.