Abstract: There is provided the reagent layer composition that can substantially reduce the measurement bias arising from hematocrits. The addition of fatty acid (4-20 carbons) and quaternary ammonium salt to a commonly used reagent layer composition composed of an enzyme, an electron transfer mediator, and several water soluble polymers not only reduce the hematocrit level-dependent bias but also provide very stable performance for an extended period of time. Disclosed are also various types of sub microliter sample volume electrochemical biosensors that are suitable to use with the reagent layer composition of present invention.

Abstract: There is provided electrochemical biosensors with a sample introducing part, comprising a sample introducing passage, an air discharge passage, and a void. The sample introducing passage communicates with the air discharge passage, and the void is formed at the point of communication. Also, disclosed is the electrochemical biosensor with the said sample introducing part and a fluidity determining electrode.

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 membrane for a sensor, a method for the preparation thereof, a layered membrane structure and a sensor for analytical measurements which require controlled analyte permeability. The membrane, layered structure and sensor may be used for biological, physiological and chemical measurements, however, are especially applicable for electrochemical measurements of glucose, lactate, urea and creatinine. The membrane comprises at least one polymer material, at least one surfactant, and at least one hydrophilic compound in admixture to provide a membrane structure in which micelles of hydrophilic compound lined with thin layers of surfactant are randomly distributed in the bulk polymer of the membrane. Upon conditioning of the membrane a structure of a perculating network of pores lined with surfactant is formed which has excellent permeability properties. The membrane has the additional advantage of a proper adhesion to polymer encapsulant structures.

Abstract: A biocompatible multipolymer, having a backbone comprising about 10 to 45 wt % of at least one hard segment and about 55 to 90 wt % of soft segments. The soft segments are divided into three groups, 5 to 25 wt %, of total soft segment weight, of an oxygen permeable soft segment; 5 to 25 wt %, of total soft segment weight, of a hydrophilic soft segment; and 50 to 90 wt %, of total soft segment weight, of a biostable, relatively hydrophobic soft segment.

Abstract: An amperometric sensor suitable for determining the concentration of hydrogen peroxide in a sample, said sensor comprising a ferricyanide compound which, in reduced form, functions as a mediator specific to hydrogen peroxide.

Abstract: A conductive compound of formula (I) below, an electrode coated with the conductive compound, a sensor including the electrode, and a target molecule detection method using the sensor are provided: wherein Y is a carbonyl or —NH—; R is one of H, OH, a leaving group, and a probe group; l is an integer from 3 to 6; m is an integer from 1 to 4; and n is an integer from 0 to 3.

Abstract: Disclosed is an electrochemical sensor for the determination of analytes in body fluids, e.g. glucose in blood. The sensor involves a non-conductive base which provides a flow path for the body fluid with the base having a working and counter electrode on its surface which are in electrical communication with a detector of current. The base and a cover therefore provide a capillary space containing the electrodes into which the body fluid is drawn by capillary action. The counter electrode has a sub-element which contains an electroactive material and is configured in the system (sensor and meter) to provide an error signal when insufficient body fluid is drawn into the capillary.

Abstract: A novel biosensor was accomplished using a plasma-polymerized membrane. The biosensor of the present invention is a high-performance biosensor produced by a simpler method and applicable to a wide range of fields.

Abstract: An analyte-measuring device, particularly an electrochemical sensor, is provided for measuring current values at multiple bias potential settings to assess the quality of the analyte measurement, identify interference in the signal, and calculate substantially interference-free analyte concentration measurements. The device and method are suitable for calculating substantially interference-free analyte concentration measurements when glucose is the analyte and acetaminophen is an interfering species.

Abstract: The present invention relates generally to systems and methods for improved electrochemical measurement of analytes. The preferred embodiments employ electrode systems including an analyte-measuring electrode for measuring the analyte or the product of an enzyme reaction with the analyte and an auxiliary electrode configured to generate oxygen and/or reduce electrochemical interferants. Oxygen generation by the auxiliary electrode advantageously improves oxygen availability to the enzyme and/or counter electrode; thereby enabling the electrochemical sensors of the preferred embodiments to function even during ischemic conditions. Interferant modification by the auxiliary electrode advantageously renders them substantially non-reactive at the analyte-measuring electrode, thereby reducing or eliminating inaccuracies in the analyte signal due to electrochemical interferants.

Abstract: Diagnostic dry reagent tests capable of reacting with a single drop of whole blood and reporting both glucose and beta-hydroxybutyrate levels are taught. Such dry reagent tests may employ electrochemical detection methodologies, optical detection methodologies, or both methodologies. These tests help facilitate the early detection of the onset of ketoacidosis in diabetes.

Abstract: A system for measuring a glucose level in a blood sample includes a test strip and a meter. The test strip includes a sample chamber or other testing zone, a working electrode, a counter electrode, fill-detect electrodes, and an auto-on conductor. A reagent layer is disposed in the testing zone. The auto-on conductor causes the meter to wake up and perform a test strip sequence when the test strip is inserted in the meter. The meter uses the working and counter electrodes to initially detect the blood sample in the sample chamber and uses the fill-detect electrodes to check that the blood sample has mixed with the reagent layer. The meter applies an assay voltage between the working and counter electrodes and measures the resulting current. The meter calculates the glucose level based on the measured current and calibration data saved in memory from a removable data storage device associated with the test strip.

Abstract: A system for measuring a glucose level in a blood sample includes a test strip and a meter. The test strip includes a sample chamber, a working electrode, a counter electrode, fill-detect electrodes, and an auto-on conductor. A reagent layer is disposed in the sample chamber. The auto-on conductor causes the meter to wake up and perform a test strip sequence when the test strip is inserted in the meter. The meter uses the working and counter electrodes to initially detect the blood sample in the sample chamber and uses the fill-detect electrodes to check that the blood sample has mixed with the reagent layer. The meter applies an assay voltage between the working and counter electrodes and measures the resulting current. The meter calculates the glucose level based on the measured current and calibration data saved in memory from a removable data storage device associated with the test strip.

Abstract: A method of forming an electrical connection between an electrochemical cell and a meter is provided. According to the method, an electrical connection is made between a meter, by means of a wedge-shaped connector with upper and lower conductive surfaces, and an electrochemical cell comprising a first substrate with a first electrically conductive coating and a second substrate with a second electrically conductive coating, the electrically conductive coatings being disposed to face each other in a spaced apart relationship by an insulating spacer. The meter further includes a pivot point for rotating the wedge connector on the pivot point.

Abstract: A disposable electrode strip for testing a fluid sample including a laminated strip with a first and second end, a vent, an open path for receiving a fluid sample of less than one microliter beginning from the first end and connecting to the vent, a working electrode, a reference electrode and a pseudo-working electrode embedded in the laminated strip within the open path and proximate to the first end, a reagent matrix coextensive within the open path and covering the three electrodes, and conductive contacts located at the second end of the laminated strip.

Abstract: A dual sensor for the simultaneous amperometric monitoring of glucose and insulin, wherein the glucose probe is based on the biocatalytic action of glucose oxidase, and the insulin probe is based on the electrocatalytic activity of metal oxide. Further provided is an oxidase enzyme composite electrode with an internal oxygen-rich binder. The present invention also optionally includes metallizing components within the carbon paste to eliminate signals from interfering compounds. The present invention includes embodiments for both in vitro and in vivo uses.

Abstract: A highly sensitive biosensor that uses a smaller amount of sample for measurement is described. The biosensor includes a first insulating base plate having a working electrode, a second insulating base plate having a counter electrode opposed to the working electrode, and a reagent layer containing at least an oxidoreductase. The biosensor further includes a sample supply pathway formed between the first and second insulating base plates, where the working electrode, counter electrode and reagent layer are exposed to an inside of the sample supply pathway, and the distance between the working electrode and the counter electrode is 150 ?m or less.

Abstract: Devices and methods for determining the concentration of an analyte in a physiological sample are provided. The subject devices are meters characterized by having an internal structure that includes a test strip selecting element having a continuously reduced cross-sectional area configured to select a single test strip at a time and means for determining the concentration of an analyte in a physiological sample applied to the selected test strip. In the subject methods for containing at least one test strip and dispensing a single test strip at a time, a meter having at least one test strip contained therein is provided. The meter is positioned with respect to the ground to cause the single test strip to move from a contained position to a dispensed position. The subject invention also includes kits for use in practicing the subject methods.

Abstract: A biosensor in the form of a strip. In one embodiment, the biosensor strip comprises an electrode support, a first electrode, i.e., a working electrode, a second electrode, i.e., a counter electrode, and a third electrode, i.e., a reference electrode. Each of the electrodes is disposed on and supported by the electrode support. Each of the electrodes is spaced apart from the other two electrodes. The biosensor strip can include a covering layer, which defines an enclosed space over the electrodes. This enclosed space includes a zone where an analyte in the sample reacts with reagent(s) deposited at the working electrode. This zone is referred to as the reaction zone. The covering layer has an aperture for receiving a sample for introduction into the reaction zone. The biosensor strip can also include at least one layer of mesh interposed in the enclosed space between the covering layer and the electrodes in the reaction zone.

Abstract: A device for sampling a biological fluid and measuring a target analyte within the biological fluid is provided. The device has at least one micro-piercing member used to penetrate the skin to a selected depth and access biological fluid, a sampling means and a measuring means. The sampling means comprises a fluid transfer medium, such as a hydrophilic porous material, by which sampled biological fluid is transferred from the micro-piercing member to the measuring means. The measuring means includes an electrochemical cell having at least one porous electrode and, typically, a reagent material, where the electrochemical cell is configured so as to make an electrochemical measurement of a target analyte in accessed biological fluid present therein. Methods of sampling biological fluids within the skin and measuring the sampled fluids are also provided, as well as kits comprising one or more of the inventive devices.

Abstract: A device for sampling a biological fluid and measuring a target analyte within the biological fluid is provided. The device has at least one micro-piercing member used to penetrate the skin to a selected depth and access biological fluid, a sampling means and a measuring means. The sampling means comprises a fluid transfer medium, such as a hydrophilic porous material, by which sampled biological fluid is transferred from the micro-piercing member to the measuring means. The measuring means includes an electrochemical cell having at least one porous electrode and, typically, a reagent material, where the electrochemical cell is configured so as to make an electrochemical measurement of a target analyte in accessed biological fluid present therein. Methods of sampling biological fluids within the skin and measuring the sampled fluids are also provided, as well as kits comprising one or more of the inventive devices.

Abstract: A system for measuring a glucose level in a blood sample includes a test strip and a meter. The test strip includes a sample chamber or other testing zone, a working electrode, a counter electrode, fill-detect electrodes, and an auto-on conductor. A reagent layer is disposed in the testing zone. The auto-on conductor causes the meter to wake up and perform a test strip sequence when the test strip is inserted in the meter. The meter uses the working and counter electrodes to initially detect the blood sample in the sample chamber and uses the fill-detect electrodes to check that the blood sample has mixed with the reagent layer. The meter applies an assay voltage between the working and counter electrodes and measures the resulting current. The meter calculates the glucose level based on the measured current and calibration data saved in memory from a removable data storage device associated with the test strip.

Abstract: An apparatus for determining the concentration of a substrate in a sample solution using an electrode system comprising a working electrode, a counter electrode, and a reaction layer which contains at least an oxidoreductase and an electron mediator and is formed on the electrode system to electrochemically measure a reduced amount of the electron mediator resulting from enzyme reaction in the reaction layer, wherein a third electrode is formed as an interfering substance detecting electrode. A current flowing between the counter electrode and the third electrode is measured which is taken as a positive error. Subsequently, voltage application between the counter electrode and the third electrode is released and a voltage for oxidizing the reduced form electron mediator is applied between the working electrode and the counter electrode to measure a current flowing between the two electrodes.

Abstract: A micron-scale self-referencing microsensor is disclosed which uses an enzyme-based electrode to measure the flux of an electrochemically inactive analyte such as glucose. The electrode oscillates between at least two positions. In the presence of the analyte, the enzyme generates a species detectable by the electrode.

Abstract: An implantable chip biosensor for detecting an analyte in vivo in body fluids comprises an analyte-sensitive hydrogel slab chemically configured to vary its displacement volume according to changes in concentration of an analyte, such as glucose, in a patient's body fluid, the slab being disposed in a groove in a support block. The biosensor chip is ‘read’ by an external scanner configured to quantifiably detect changes in the displacement volume of the hydrogel slab. The support block is made of rigid or semi-rigid support material to restrain expansion of the hydrogel in all but one dimension, and the groove has one or more openings covered with a semipermeable membrane to allow contact between the patient's body fluid and the hydrogel. The scanning means may be any type of imaging devices such as an ultrasound scanner, a magnetic resonance imager (MRI), or a computerized tomographic scanner (CT) capable of resolving changes in the slab's dimensions.

Abstract: A device and method for glucose quantification in a liquid medium using a reference electrode; a counter electrode and a working electrode with a semipermeable membrane is provided.

Abstract: A system for measuring a glucose level in a blood sample includes a test strip and a meter. The test strip includes a sample chamber, a working electrode, a counter electrode, fill-detect electrodes, and an auto-on conductor. A reagent layer is disposed in the sample chamber. The auto-on conductor causes the meter to wake up and perform a test strip sequence when the test strip is inserted in the meter. The meter uses the working and counter electrodes to initially detect the blood sample in the sample chamber and uses the fill-detect electrodes to check that the blood sample has mixed with the reagent layer. The meter applies an assay voltage between the working and counter electrodes and measures the resulting current. The meter calculates the glucose level based on the measured current and calibration data saved in memory from a removable data storage device associated with the test strip.

Abstract: An electrochemical cell having an auxiliary area that contains a redox species on a working electrode. The auxiliary area provides a low resistance current path between the working electrode and a pseudo reference/counter electrode. The auxiliary area is an integral part of the working electrode and allows an enhanced current to flow. The enhanced current adds to the measurement signal. This reduces non-monotonic current decay, which can lead to erroneous analyte measurements.

Abstract: A sensor and method for detecting biological and chemical agents comprising metal interdigitized electrodes coated with hybrid polymer-based conducting film and an instrument for applying electrical voltage to the electrodes and registering the change in voltage. The hybrid film also comprises indicator biomolecules encapsulated within the film or attached to it. When these indicator biomolecules come in a contact with a biological and chemical agent, morphological changes occur in the film and electrical current flowing through the electrodes is modulated. The change in current indicates the presence of a biological and chemical agent and is registered.

Abstract: Disclosed is a porous membrane built-in biosensor comprising (a) at least one substrate; (b) an electrode layer patterned on the substrate, consisting of an electrode system and a circuit connector; (c) an insulator, formed on parts of the electrode layer, for electrically separating the electrode system from a circuit connector; and (d) a porous membrane via the insulator on the electrode system, wherein, when a whole blood sample is introduced to the biosensor, the whole blood sample is separated into its components during the chromatographic motion through the porous membrane so that only blood plasma can be contacted with the electrode system. The porous membrane built-in biosensor is provided with a sample inlet, which allows samples to be introduced in a constant quantity to the biosensors porous membranes without pretreatment.

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 biosensor enabling accurate measurement of the concentration of a substrate contained in a trace amount of a sample solution is disclosed. The electrochemical analysis element in accordance with the present invention which should be included in the biosensor comprises a sensor body having a hollow space which space is open at its both ends, an electrode system having a working electrode and a counter electrode, a reagent segment containing an enzyme, wherein the electrode system and the reagent segment are disposed on an inner wall of the hollow space.

Abstract: The invention relates to a sensor for detecting substance concentration or activity or for determining the presence of substances based on electrochemical reactions. The electrochemical sensor comprises an electrode with surfaces inside the electrode, wherein electrochemical detection reactions occur. Said sensor guarantees high flow densities and is suitable for miniaturization. A substance-recognizing agent is advantageously placed in the electrode in contact with the inner surfaces. This enables not only short response times and long service life but also measurements with excellent linearity.

Abstract: Disclosed is an electrochemical sensor for the determination of analytes in body fluids, e.g. glucose in blood. The sensor involves a non-conductive base which provides a flow path for the body fluid with the base having a working and counter electrode on its surface which are in electrical communication with a detector of current. The base and a cover therefore provide a capillary space containing the electrodes into which the body fluid is drawn by capillary action. The counter electrode has a sub-element which contains an electroactive material and is configured in the system (sensor and meter) to provide an error signal when insufficient body fluid is drawn into the capillary.

Abstract: An electrochemical sensor system and membrane and method thereof for increased accuracy and effective life of electrochemical and enzyme sensors.

Abstract: A biosensor device for adding the amperage of the conductive film, the biosensor comprises a base comprising a first base and a second base and both those be clapped to each other and said second base be located a test hole; a electrode film comprising a first electrode film and a second electrode film, said first electrode be located on said first base and including a anode electrode film and a cathode electrode film and said second electrode film be located on the second base and located the side of side test hole; a conductive film be located on said first base, including a anode and cathode conductive film of phase separation; a bioactive layer be located on the said first electrode film to form a active area that at least covering a portion of said anode and cathode electrode film; and a adhesive layer connected between said first base and said second base to adhere said first base and said second base that said test hole of it corresponded to said active area of said first base.

Abstract: A sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 &mgr;L. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable.

Abstract: An insertable analyte needle sensor, comprising a set of fine wires positioned together and a dielectric material covering a substantial portion of the fine wires but defining an opening filled with at least one partially permeable membrane. The wires may be treated with a gas plasma to facilitate membrane adherence. One membrane layer may comprise sulphonated polyethersulphone coated with silane.

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 sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 &mgr;L. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable. The amount of analyte can be determined by coulometry. One particular coulometric technique includes the measurement of the current between the working electrode and a counter or reference electrode at two or more times. The charge passed by this current to or from the analyte is correlated with the amount of analyte in the sample.

Abstract: An electrochemical test device is provided for determining the presence or concentration of an analyte in an aqueous fluid sample. The electrochemical test device includes a working electrode and a counter electrode made of an amorphous semiconductor material. The working electrode is overlaid with a reagent capable of reacting with an analyte to produce a measurable change in potential which can be correlated to the concentration of the analyte in the fluid sample. The test device optionally contains a reference electrode made of an amorphous semiconductor material having a reference material on the reference electrode.

Abstract: A sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 &mgr;L. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable. The amount of analyte can be determined by coulometry. One particular coulometric technique includes the measurement of the current between the working electrode and a counter or reference electrode at two or more times. The charge passed by this current to or from the analyte is correlated with the amount of analyte in the sample.

Abstract: A predetermined voltage is applied to a biosensor twice to promote an electrochemical reaction, and the following parameters (P1 and P2) are calculated from the values of detected current. A statistical technique is used with these parameters to compensate for errors so that the concentration of an object can be determined. P1: the ratio (If/Ib) of the maximum current (If) or a current occurring the maximum in the first excitation to a current (Ib) read at any point in the second excitation. P2: a current (Ib) read at any point in the second excitation.

Abstract: A bilateral biosensor based upon a microporous architecture is provided which seeks to reduce the effect of co-reactant concentration limitations by utilizing a new sensor microgeometry. If implemented on the appropriate scale, the new sensor design augments substantially the concentration of oxygen, or other co-reactants or reagents, in the reaction zone of the sensor. Performance enhancements over traditional microscale devices employing unilateral orientation are accomplished, in one embodiment, by allowing analyte to enter the sensor from one side of the sensor, while allowing a co-substrate to enter from both sides of the sensor.

Abstract: The present invention provides a diffusion limiting membrane system for filtering an analyte from a fluid, comprising: a) a first layer comprising an analyte responsive enzyme; and b) a second layer comprising a water-soluble monomer composition, wherein the first layer is in direct contact with one or more sensor electrodes and the second layer is in direct contact with the first layer.

Abstract: Disclosed is an electrochemical sensor for detecting the concentration of an analyte such as glucose in a fluid test sample. The sensor involves a base as flow path for the fluid test sample having a working and counter electrode on its surface. The base is mated with a cover to form a capillary space to capture the fluid and the counter electrode has a sub-element located upstream in the flow path. When there is detected electrical communication only between the sub-element and the working electrode the meter, with which the sensor is in electrical communication senses that the capillary space has not completely filled with test fluid.

Abstract: The present invention relates to a test strip and a biosensor having an increased conductivity and a slurry comprising a fiber, meal particles having a size in nanometer and a bioactive substance. The invention is characterized by incorporating metal particles having size in nanometer into the reaction layer of test strip and biosensor to increase the conductivity between the reaction layer and the electrodes so that the redox reaction can be readily completed and the measurement time can thus be shortened.

Abstract: An electrode assembly for sensing an electrochemical signal diffused from a source to a working electrode which is comprised of a plurality of substantially separated working electrode surfaces is disclosed. The electrode of the invention is comprised of 1) a working electrode made up of a plurality of working electrode surfaces or components and 2) a electrically insulating gap defined by adjacent edges of 1) insulating the working electrode surfaces or components from each other. The working electrode components are configured to receive electrochemical signal from two or preferably three dimensions simultaneously. The working electrode components configured over the same surface as a single electrode provide (1) an improved signal to noise ratio as compared to a single electrode by reducing noise, and (2) provide an overall enhanced signal after sensing for a given period of time.