Abstract: A sensor, and methods of making, for determining the concentration of an analyte, such as glucose or lactate, in a biological fluid such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. The sensor includes a working electrode and a counter electrode, and can include an insertion monitoring trace to determine correct positioning of the sensor in a connector.

Abstract: A thin film sensor, such as a glucose sensor, is provided for transcutaneous placement at a selected site within the body of a patient. The sensor includes several sensor layers that include conductive layers and includes a proximal segment defining conductive contacts adapted for electrical connection to a suitable monitor, and a distal segment with sensor electrodes for transcutaneous placement. The sensor electrode layers are disposed generally above each other, for example with the reference electrode above the working electrode and the working electrode above the counter electrode. The electrode layers are separated by dielectric layer.

Abstract: A biosensor comprises a space part for sucking and housing a sample formed of two upper and lower plates, the two plates being stuck together by an adhesive layer, the space part for sucking and housing the sample being constituted so as to be partially opened in the peripheral part and partially closed by the adhesive layer, and has a working electrode having at least glucose oxidase immobilized thereon and a counter electrode on the same plane of the plate.

Abstract: A test strip and analytical apparatus have pin connections permitting the definition of geographic regions or of particular customers. A test strip made for use in a particular region or for a particular customer will have pin connections matching features of the apparatus made for use in that region or by that customer. Insertion of the strip into the apparatus does not merely turn on the apparatus, but provides the regional or customer coding. Analog switches within the apparatus allow coding of a larger number of distinct regions or customers than would otherwise be possible, all without degrading the quality of the measurements made of the fluid being tested. Conductive paths in the strips permit testing the strips during manufacture so as to detect quality lapses regarding the printing or deposition of the paths.

Abstract: A test system for measuring analyte concentration in a fluid sample includes: (i) a capillary-fill biosensor (20) having a working electrode (24), a reference electrode (22) and a separate counter electrode (23), arranged such that a fluid sample which flows evenly along the capillary flow path will substantially completely cover the reference electrode (22) before the fluid sample makes contact with any part of the counter electrode (23); and (ii) a test meter (42) for receiving the biosensor (20), the meter (42) including: first signal circuitry (31) for producing a first signal when an electrical circuit is detected between the reference electrode (22) and the working electrode (24); second signal circuitry (33) for producing a second signal when an electrical circuit is detected between the counter electrode (23) and at least one of the reference electrode (22) and the working electrode (24); a timer (35) for determining the time interval between production of said first signal and said second signal;

Abstract: The present invention provides methods for the use of enzymes to selectively deposit metal to the vicinity of a target molecule. The invention also relates to applications of enzymatic metal deposition to sensitively and selectively detect target molecules such as biomarkers in various biological samples, such as chromogenic immunohistochemical (IHC) detection in situ by using bright field light microscope.

Abstract: Disclosed are methods and devices for biomolecular detection, comprising a nanopipette, exemplified as a hollow inert, non-biological structure with a conical tip opening of nanoscale dimensions, suitable for holding an electrolyte solution which may contain an analyte such as a protein biomolecule to be detected as it is passed through the tip opening. Biomolecules are detected by specific reaction withy peptide ligands chemically immobilized in the vicinity of the tip. Analytes which bind to the ligands cause a detectible change in ionic current. A sensitive detection circuit, using a feedback amplifier circuit, and alternating voltages is further disclosed. Detection of Il-10 at a concentration of 4 ng/nl is also disclosed, as is detection of VEGF.

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: A measuring device for the detection and determination of the concentration of at least one analyte in a liquid medium consists of a polymeric carrier having biologically active specific binding molecules dried on its upstream portion. A multiple electrode set consisting of at least one reference electrode and at least one working electrode is located thereon in a downstream region. The working electrode is provided with biologically active specific binding molecules. The carrier has a sample application zone, which is adjoined, in the downstream direction, by a non-deformable, through-flow reaction and detection chamber, a variably dimensioned interstice, and a liquid absorption element. For a qualitative and quantitative analyte determination, two liquid media are applied in succession to the sample application zone. While the first can contain the wanted analyte, the second provides for the formation of an electrical signal.

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: In a biosensor for measuring a specific substance in a liquid sample, one or a combination of sugar alcohol, metallic salt, organic acid or organic acid salt which has at least one carboxyl group in a molecule, and organic acid or organic acid salt which has at least one carboxyl group and one amino group in a molecule, is included in a reagent layer provided on electrodes, thereby providing a highly-accurate biosensor which is excellent in stability and has high response (sensitivity, linearity) of the sensor to the substrate concentration.

Abstract: A system and method for correcting the oxygen effect on oxidase-based analyte sensors includes an oxygen sensor with a working electrode, a reagent matrix disposed on at least the working electrode that contains a reduced form of a redox mediator, an oxidase and a peroxidase, an oxidase-based analyte sensor, a means for determining the oxygen concentration in a portion of a fluid sample using the oxygen sensor, means for determining an analyte concentration in another portion of the fluid sample using the oxidase-based analyte sensor, and means for using the oxygen concentration in the fluid sample to determine a corrected analyte concentration in the fluid sample.

Abstract: A sensor, and methods of making, for determining the concentration of an analyte, such as glucose or lactate, in a biological fluid such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. The sensor includes a working electrode and a counter electrode, and can include an insertion monitoring trace to determine correct positioning of the sensor in a connector.

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: 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: 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: The present invention is based on the discovery of NAD+ and NADP+ mediator compounds that do not bind irreversibly to thiol groups in the active sites of intracellular dehydrogenase enzymes. Such mediator compounds avoid a common mode of enzyme inhibition. The mediators can therefore increase the stability and reliability of the electrical response in amperometric electrodes constructed from NAD- or NADP-dependent enzymes.

Abstract: The invention relates generally to methods and apparatus for conducting analyses, particularly microfluidic devices for the detection of target analytes.

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 improved biosensor having at least a first working electrode and a first electrode material disposed on the first working electrode. The first electrode material is a mixture made by combining at least one enzyme where the at least one enzyme is a capable of reacting with the analyte to be measured, a redox mediator capable of reacting with a product of an enzymatic reaction or a series of enzymatic reactions involving the at least one enzyme, a peroxidase capable of catalyzing a reaction involving the redox mediator where the redox mediator is oxidized, a binder and a surfactant.

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: A substantially planar electrochemical test strip for determination of the presence and/or quantity of an analyte in a sample is provided that has a first electrode, a first connector including two contact pads, and a first conductive lead extending between the first electrode and the first connector to establish a path for conduction of an electrical signal between the first electrode and the first connector; a second electrode, a second connector including one or more contact pads, and a second conductive lead extending between the second electrode and the second connector to establish a path for conduction of an electrical signal between the second electrode and the second connector, and a sample chamber for receiving a sample. The first and second electrode are disposed to contact a sample within the sample chamber such that an electrochemical signal is generated. The contact pad or pads of the second connector are between the contact pads of the first connector when viewed in the plane of the test strip.

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.

Abstract: There is provided a biosensor (which is integrated with a needle) with a high precision where an assembling is easy and reproducibility of the prepared biosensor (integrated with a needle) is good. There is provided with a biosensor comprising: two sheets of electrically insulating substrates connected by a connecting part, and an electrode and a spacer formed on one of or both of the two sheets of electrically insulating substrates, wherein the two sheets of the electrically insulating substrates are folded along the connecting part, and the electrode and the spacer are positioned between the electrically insulating substrates.

Abstract: A sensor strip comprises an electrode substrate, an electrode set, on the electrode substrate, and a heat conducting layer, on the electrode substrate opposite the electrode set. A sensor instrument for use with this sensor strip comprises a temperature sensor, at a side of a gap for accepting the sensor strip, opposite electrical contacts. The invention provides an accurate determination of the temperature of a sample.

Abstract: The present invention relates to a disposable electrochemical sensor which can measure redox species in a liquid sample

Abstract: The present invention is based on the discovery of NAD+ and NADP+ mediator compounds that do not bind irreversibly to thiol groups in the active sites of intracellular dehydrogenase enzymes. Such mediator compounds avoid a common mode of enzyme inhibition. The mediators can therefore increase the stability and reliability of the electrical response in amperometric electrodes constructed from NAD- or NADP-dependent enzymes.

Abstract: A biosensor that utilizes a mediator, i.e., an isomer of phenanthroline quinone, 1,10-phenanthroline-5,6-dione, and a metal ion, such as manganese, with an enzyme dependent upon NAD(P)+, such as, for example, glucose dehydrogenase, for improving the hematocrit bias and oxygen bias of biosensors. The electrodes of the biosensors employing this mediator and a metal ion provide an accurate clinical response over a hematocrit range that ranges from about 20% to about 70% and over an oxygen tension range that ranges from about 1 kPa to about 20 kPa.

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. The transition metal complexes include substituted or unsubstituted (pyridyl)imidazole ligands. Transition metal complexes attached to polymeric backbones are also described.

Abstract: The assay devices, assay systems and device components of this invention comprise at least two opposing surfaces disposed a capillary distance apart, at least one of which is capable of immobilizing at least one target ligand or a conjugate in an amount related to the presence or amount of target ligand in the sample from a fluid sample in a zone for controlled fluid movement to, through or away the zone. The inventive device components may be incorporated into conventional assay devices with membranes or may be used in the inventive membrane-less devices herein described and claimed. These components include flow control elements, measurement elements, time gates, elements for the elimination of pipetting steps, and generally, elements for the controlled flow, timing, delivery, incubation, separation, washing and other steps of the assay process.

Abstract: A biosensor for use in determining a concentration of a component in an aqueous liquid sample is provided including: an electrochemical cell having a first electrically resistive substrate having a thin layer of electrically conductive material, a second electrically resistive substrate having a thin layer of electrically conductive material, the substrates being disposed with the electrically conductive materials facing each other and being separated by a sheet including an aperture, the wall of which aperture defines a cell wall and a sample introduction aperture whereby the aqueous liquid sample may be introduced into the cell; and a measuring circuit.

Abstract: The present invention concerns a polymer layer for a sensor, wherein the polymer layer has nanoparticles embedded therein which impart to the polymer layer recognizing properties as well as transducer properties, a sensor comprising such layer and the use of the sensor for detecting and/or quantifying a target analyte.

Abstract: Provided is an electrochemical sensor strip having circuits comprising electrodes in an electrode region connected to contact pads in a contact region by conductive traces wherein the electrode region is off-set from the contact region in both an x direction parallel to the length of the sensor strip and a y direction parallel to the width of the sensor strip. Also provided is a an electrochemical sensor strip having a backing material, an active portion laminated to a portion of the backing material, the active portion comprising a substrate, a circuit comprising electrodes in an electrode region connected to contact pads in a contact region by conductive traces wherein the electrode region is off-set from the contact region in both an x direction parallel to the length of the sensor strip and a y direction parallel to the width of the sensor strip, a polymeric layer comprising a channel-forming material over the electrodes, and a hydrophilic layer over the channel-forming material.

Abstract: A bio-battery includes a biomolecular energy source, a first electrode and a second electrode. In some configurations, a bio-battery may also include a first cell containing the first electrode and the biomolecular energy source, and a second cell having a reducible substrate and the second electrode. The first cell can be in ionic communication with the second cell, for example by a proton exchange membrane. Various biomolecular energy sources can be used, including proton donor molecules or electrolytically oxidizable molecules. For example, the biomolecular energy source can be selected from the group consisting of Nicotinamide Adenine Dinucleotide (NADH), Nicotinamide Adenine Dinucleotide Phosphate (NADPH) and 5,10-Methylenetetrahydrofolate Reductase (FADH).

Abstract: Disclosed are methods and materials for utilizing enzymes to act on metal ions in solution so that the ions are reduced to metal and deposited. These methods enable a wide range of applications including the detection of one or more constituents in a test sample.

Abstract: We provide a lactate biosensing strip comprising a working electrode and a reference electrode, the two electrodes being deposited on an electrically insulated base support, the working electrode being formed by immobilizing lactate oxidase and an electron mediator on an inorganic graphite matrix and the graphite layer being deposited on a silver layer of the working electrode and the reference electrode being formed by depositing silver chloride on a silver layer of the reference electrode.

Abstract: A biosensor measuring an analyte contained in a sample is provided, including: an insulative lower substrate that has at least one electrode on which an enzyme reaction layer reacting with the analyte is formed; an upper substrate that faces the lower substrate and is made of a conductive material; and an adhesive layer that has a sample feed with a predetermined height on the enzyme reaction layer and attaches the upper and lower substrates to each other, where an end of the upper substrate acts as an electrode in which an electron-transfer mediator contained in the enzyme reaction layer is oxidized or reduced, and the other end acts as an electrical contact part that electrically contacts a measurement unit.

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. In another embodiment, the assembly of conducting layers and insulating layers can be formed on both major surfaces of the insulating substrate. The assembly can comprise at least one working electrode and at least one other electrode, e.g., a dual-purpose reference/counter electrode.

Abstract: An integrated lancing and measurement device is provided comprising a sensor designed to determine the amount and/or concentration of analyte in a biological fluid having a volume of less than about 1 ?L. A piercing member is adapted to pierce and retract from a site on the patient to cause the fluid to flow therefrom, and the sensor is positioned adjacent to the site on the patient so as to receive the fluid flowing from the site to generate an electrical signal indicative of the concentration of the analyte in the fluid. The sensor is comprised of a working electrode comprising an analyte-responsive enzyme and a redox mediator, and a counter electrode. An analyte monitor is operatively connected to the sensor and adapted to measure the signal generated by the sensor. Also provided are analyte measuring methods that optionally employ the integrated lancing and measurement device.

Abstract: A biosensor capable of measuring the concentration of one or more specific substances in one or more sample solutions almost simultaneously is provided. The biosensor comprises a plurality of sensor units, and each of the sensor units comprises an electrode system including a working electrode and a counter electrode on an insulating base plate and a reagent system including an oxidoreductase and an electron mediator. The biosensor is so configured that sample solutions supplied to the respective sensor units reach the respective reagent systems at different times. Specifically, each of the sensor units has a controlling system between a sample supply inlet and the reagent system, and the controlling system controls the time it takes for the sample solution to reach the reagent system from the sample supply inlet.

Abstract: We provide a lactate biosensing strip comprising a working electrode and a reference electrode, the two electrodes being deposited on an electrically insulated base support, the working electrode being formed by immobilizing lactate oxidase and an electron mediator on an inorganic graphite matrix and the graphite layer being deposited on a silver layer of the working electrode and the reference electrode being formed by depositing silver chloride on a silver layer of the reference electrode.

Abstract: Analytes in a liquid sample are determined by methods utilizing sample volumes of less than about 1.5 ?l and test times within ten seconds. The methods are preferably performed using small test strips including a sample receiving chamber filled with the sample by capillary action.

Abstract: Described are micro-arrays of electrodes disposed proximal to a flexible substrate, electronic components and sensors comprising such arrays, and methods of use for such arrays.

Abstract: A biosensor comprising: an electrically insulating base plate; an electrode system comprising a working electrode and a counter electrode formed on the base plate; a cover member which is joined to the base plate to form a sample solution supply pathway for supplying a sample solution to the electrode system between the cover member and the base plate; and a reagent system comprising at least an oxidoreductase and an electron mediator disposed in the sample solution supply pathway, wherein the electron mediator is provided on the base plate and the oxidoreductase is provided on the cover member such that the electron mediator and the oxidoreductase are not in contact with each other.

Abstract: Electrodes and configurations for electrochemical bioreactor systems that can use electrical energy as a source of reducing power in fermentation or enzymatic reactions and that can use electron mediators and a biocatalyst, such as cells or enzymes, to produce electricity are disclosed. Example electrodes in the system may comprise: (1) neutral red covalently bound to graphite felt (FIG. 1); (2) a carboxylated cellulose bound to the graphite fell, neutral red bound to the carboxylated cellulose, NAD+ to the graphite fell, and an oxidoreductase (e.g., fumarate reductase) bound to the graphite fell; or (3) a metal ion electron mediator bound to graphite. Various biocatalysts, such as an oxidoreductase, cells of Actinobacillus succinogenes, cells of Escherichia coli, and sewage sludge, are suitable for use in the electrochemical bioreactor system.

Abstract: A non-mediated enzyme electrode comprises a base substrate (2) on which is provided an electrically conductive base layer (8) comprising finely divided platinum group metal or oxide bonded together by a resin; a top layer on the base layer (8), the top layer comprising a buffer. A catalytically active quantity of an oxidoreductase enzyme is provided in at least one of the base layer and the top layer. The invention also provides a biosensor (20) which includes an enzyme electrode, and methods of manufacturing the enzyme electrode and biosensor.

Abstract: Disclosed is a water-soluble PQQGDH wherein two subunits are linked together via a disulfide bond. The water-soluble PQQGDH of the invention exhibits improved thermal stability.

Abstract: A polymer based enzyme electrode useful for estimation for cholesterol is disclosed. The electrode has an ion-doped layer to increase the conductivity of the poly pyrrole layer. The ion doping is achieved by incorporating dodecyl benzene sulphonate (DBS) in the poly pyrrole film deposited by electrochemical deposition The enhanced conductivity due to ion doping helps in faster estimation of cholesterol having a measured response time of 30 seconds. The shelf life of the electrode is at least eight weeks without a mediator at room temperature.

Abstract: An electrochemical biosensor formed by screen printing and method of fabricating such biosensor is disclosed in the present invention. The biosensor can quickly absorb a sample to be measured therein, effectively control volume of the sample fed and “fill-and-position” the sample therein. The biosensor includes an electrode layer (electrode area) comprising two or three electrodes, which are a working electrode, a reference electrode and an auxiliary electrode (tri-electrode) on an insulating substrate. An active reaction layer containing reactant, reaction catalyst, mediator, wetting agent and surfactant is spread on the surface of the electrode layer. A sample inflow area is formed above the electrode area by adding an upper cover on top of a middle insulating layer with a U-shaped opening formed therein. Sample solution with a minute amount about 0.

Abstract: An electrochemical test sensor adapted to assist in determining the concentration of analyte in a fluid sample is disclosed. The sensor comprises a base that assists in forming an opening for introducing the fluid sample, a working electrode being coupled to the base, and a counter electrode being coupled to the base, the counter electrode and the working electrode being adapted to be in electrical communication with a detector of electrical current, and a sub-element being coupled to the base. A major portion of the counter electrode is located downstream relative to the opening and at least a portion of the working electrode. The sub-element is located upstream relative to the working electrode such that when electrical communication occurs between only the sub-element and the working electrode there is insufficient flow of electrical current through the detector to determine the concentration of the analyte in the fluid sample.