Abstract: The present invention provides a highly sensitive biosensor capable of yielding good response even when the amount of a sample is extremely small. The biosensor of the present invention includes: a first insulating base plate which has a working electrode comprising a plurality of branches and a first counter electrode comprising a plurality of branches, the branches of the working electrode and the first counter electrode being arranged alternately; a second insulating base plate which has a second counter electrode and which is disposed at a position opposite to the first insulating base plate; a reagent system comprising an oxidoreductase; and a sample supply pathway formed between the first and second insulating base plates, wherein the branches of the working electrode and the first counter electrode that are arranged alternately, the second counter electrode, and the reagent system are exposed in the sample supply pathway.

Abstract: The present invention concerns an electrode carrying immobilized redox enzymes such that electric charge can flow between an electron mediator group to the enzyme cofactor by the use of boronic acid or a boronic acid derivative that acts as a linker moiety between the cofactor and the electron mediator group. The invention also concerns devices and systems that make use of the electrode of the invention, such as bio-sensors and fuel cells, the electrode being one of the components thereof.

Abstract: The present invention provides a high-performance glucose sensor having excellent storage stability and an improved response characteristic. This sensor comprises: an electrically insulating base plate; an electrode system including at least a working electrode and a counter electrode formed on the base plate; and a reaction layer containing at least pyrrolo-quinoline quinone dependent glucose dehydrogenase, formed in contact with or in the vicinity of the electrode system, and the reaction layer contains at least one kind of additive selected from the group consisting of gluconic acid and salts thereof.

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: In biosensor system 1, biosensor 2 is mounted in measuring apparatus 3 for quantifying or detecting existence of a targeted substrate in a sample solution. Mounting end portion 20 of biosensor 2 to be mounted in measuring apparatus 3 has an extension of one base plate in the length direction, and further extensions of the other base plate in the width direction. Sensor mounting portion 30 of measuring apparatus 3 has a shape matching up with the shape of mounting end portion 20. Thereby wrong insertion of biosensor 2 in measuring apparatus 3 can be prevented. Further, varying shapes of plural biosensors 5 and 6 to have a common part and a non-common part, such biosensors can be handily measured by one measuring apparatus 7.

Abstract: A test sensor having a pair of electrodes and a reagent for electrochemically measuring the concentration of the analyte in a liquid sample. The test sensor comprises a capillary channel for collecting the liquid sample and a conductor disposed outside the capillary channel. The conductor is in fluid communication with the capillary channel. The liquid test sample is collected and moved through the capillary channel. The liquid test sample contacts the conductor when the capillary channel is substantially full to signal a full condition.

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 device having a flow channel, wherein at least one flow-terminating interface is used to control the flow of liquid in the flow channel. The flow-terminating interface prevents the flow of the liquid beyond the interface. In one aspect, the invention provides a sensor, such as, for example, a biosensor, in the form of a strip, the sensor being suitable for electrochemical or optical measurement. The sensor comprises a base layer and a cover layer, and the base layer is separated from the cover layer by a spacer layer. The base layer, cover layer, and spacer layer define a flow channel into which a liquid sample is drawn therein and flows therethrough by means of capillary attraction. The flow of the sample is terminated by a flow-terminating interface positioned in the flow channel.

Abstract: An electronic controller, such as a programmed microcontroller, controls a series of pumps to automatically sequence the pumping of the individual fluids required by the ELISA procedure into a cell (or cells) necessary to produce a reporter, including the addition of o-nitrophenyl beta-D galactopyranoside substrate of the enzyme (“ONP-GP”), control the positioning of the carrier of the reporter adjacent the reporter sensor, analyze the data obtained from the reporter sensor and display the concentration of the bioagent determined from the analysis of the foregoing data. Once started, the apparatus, governed by the program, conducts the test automatically in the shortest time known to date, without the necessity for human intervention.

Abstract: In a first phase a first sensor signal, essentially comprising the current offset signal of the sensor, is applied to the input of an electronic circuit. The first sensor signal is fed to a first signal path and stored therein. In a second phase a second sensor signal, comprising the current offset signal and a time-dependent measured signal, is applied to the input and the stored first sensor signal is fed to the input by means of the first signal path, such that essentially the time dependent measured signal is fed by means of a second signal path coupled to the input.

Abstract: A biosensor is constituted by disposing an electrode system including a working electrode and a counter electrode on a substrate, forming an inorganic particulate-containing layer containing inorganic particulates thereon, and forming a reagent layer containing a reagent thereon. The inorganic particulates make it possible to prevent impurities in a sample from being in contact with the electrode system and being adsorbed therein, so that measurement is performed with high precision. The inorganic particulate-containing layer can be formed by applying a dispersion system of inorganic particulates and drying them, and it is preferable that the inorganic particulates are contained in the form of aggregates.

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: An integrated current-to-voltage conversion circuit converts a first current to an output voltage representative of the first current. The circuit includes a first contact pad and second and third contact pads capable of being coupled across a first resistor. A first operational amplifier has a first input coupled to the first contact pad for producing a first voltage thereat, a second input for receiving a reference voltage, and a first output coupled to the third contact pad. A second voltage appears at the third contact pad. A second operational amplifier has a second output at which a third voltage appears, a first input coupled to the second output, and a second input coupled to the second contact pad. The output voltage is substantially equal to the difference between the second and third voltages.

Abstract: The present invention relates to a microelectrode, a microelectrode array, and a method of manufacturing the microelectrode of which temperature can be controlled. The microelectrode comprises a sealed cavity formed in a silicon substrate for thermal isolation, a microheater formed on the sealed cavity, and an electrode heated indirectly by the microheater. According to the present invention, it is possible to manufacture with CMOS process the microelectrode and the microelectrode array which have excellent electric insulation and thermal isolation between a microheater and a silicon substrate, which has a small power consumption, which has high heating and cooling speed and which has no corrosion.

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: A reaction layer 12 which reacts with a substance to be measured in a sample solution is provided on a working electrode 1, a counter electrode 2, and a third electrode 3 which are provided on an insulating substrate 7 so as to bridge the respective electrodes, the content of the substance to be measured is measured from a current value which reaction is obtained between the working electrode 1 and the counter electrode 2, and the types of sample solution is judged by a difference between oxidation current values or between oxidation current waveforms, which are obtained between the third electrode 3 and the counter electrode 2 or between the third electrode 3 and the working electrode 1, thereby automatically judging the types of sample solution.

Abstract: The invention provides a method for determining the concentration of an analyte in a sample comprising the steps of heating the sample and measuring the concentration of the analyte or the concentration of a species representative thereof in the sample at a predetermined point on a reaction profile by means that are substantially independent of temperature. Also provided is an electrochemical cell comprising a spacer pierced by an aperture which defines a cell wall, a first metal electrode on one side of the spacer extending over one side of the aperture, a second metal electrode on the other side of the spacer extending over the side of the aperture opposite the first electrode, means for admitting a sample to the cell volume defined between the electrodes and the cell wall, and means for heating a sample contained within the cell.

Abstract: The present invention provides an analytical element which is free from evaporation of a sample during measurement and therefore capable of quantifying a substrate using a very small amount of sample with high accuracy and which is free from scattering of the sample during and after the measurement and therefore hygienically excellent; and a measuring device and a substrate quantification method using the same. The analytical element comprises a cavity for accommodating a sample, a working electrode and a counter electrode exposed to an inside of the cavity, a reagent layer which comprises at least an oxidoreductase and is formed inside or in the vicinity of the cavity, an opening communicating with the cavity and a member covering the opening.

Abstract: The invention provides a biosensor comprising a support; a conductive layer composed of a electrical conductive material such as a noble metal, for example gold or palladium, and carbon; slits parallel to and perpendicular to the side of the support; working, counter, and detecting electrodes; a spacer which covers the working, counter, and detecting electrodes on the support; a rectangular cutout in the spacer forming a specimen supply path; an inlet to the specimen supply path; a reagent layer formed by applying a reagent containing an enzyme to the working, counter, and detecting electrodes, which are exposed through the cutout in the spacer; and a cover over the spacer. The biosensor can be formed by a simple method, and provides a uniform reagent layer on the electrodes regardless of the reagent composition.

Abstract: The present invention provides methods and systems for passively and automatically detecting the presence of a sample (the “sample detection phase”) upon application of the sample to a biosensor, identifying the sample detection time and then initiating the measurement of a targeted characteristic, e.g., the concentration of one or more analytes, of the sample (the “measurement phase”), immediately upon sample detection. The subject methods and systems do not employ or involve the application of an electrical signal from an external source to the electrochemical cell for purposes of performing the sample detection phase and are, thus, less complicated and involve fewer steps and components.

Abstract: Systems and methods are provided for determining whether a volume of biological sample is adequate to produce an accurate analyte concentration measurement. Certain such systems and methods provide the additional function of compensating for a sample volume determined to be less than adequate in order to proceed with an accurate analyte concentration measurement. The present invention is employed with a biosensor, such as an electrochemical test strip to which the sample volume of biological solution is deposited, and a meter configured to receive such test strip and to measure the concentration of selected analytes within the biological sample.

Abstract: A biosensor is provided in accordance with the present invention. The biosensor includes an electrode support substrate, electrodes positioned on the electrode support, each electrode including a meter-contact portion and a measurement portion, and a sensor support substrate. The sensor support substrate cooperates with the electrode support substrate to define channel in alignment with the measurement portion of the electrodes. Additionally, the sensor support substrate includes opposite ends and at least one window. The at least one window is spaced-apart from the ends and in alignment with the meter-contact portion of at least one of the electrodes.

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 biosensor includes a pair of conductive lead parts formed on an insulating substrate, a working electrode and a counter electrode formed at the ends of the conductive lead parts, respectively, and a reaction layer formed so as to bridge the electrodes and react with a measurement target substance in a specimen liquid. The biosensor measures the content of the measurement target substance from an electric current value based on the reaction between the measurement target substance and the reaction layer, which current value is obtained through the pair of conductive lead parts. The reaction layer is not provided above at least one of the conductive lead parts so that the reaction layer and the conductive lead parts do not contact directly even when pin holes or cracks are generated in the electrodes.

Abstract: Electrochemical test strips and methods for their use in the detection of an analyte in a physiological sample are provided. The subject test strips have a plurality of reaction zones defined by opposing metal electrodes separated by a thin spacer layer. The reagent compositions present in each reaction zone may be the same or different. In addition, each reaction zone may have a separate fluid ingress channel, or two or more of the reaction zones may have fluid ingress channels that merge into a single channel. The subject electrochemical test strips find application in the detection of a wide variety of analytes, and are particularly suited for use the detection of glucose.

Abstract: This invention relates to a method for analyzing the concentration of an analyte in a sample and to automatic analyzing apparatus. The invention will be described herein with particular reference to a method and apparatus for measuring the concentration of glucose or other analytes in blood but is not limited to that use.

Abstract: A sensor is provided for the determination of various concentrations of one or more components within a fluid sample. The sensor includes an injection molded body, at least two electrodes, an enzyme, and if desired, an electron transfer mediator. The body includes a reaction zone for receiving a fluid sample. The electrodes are at least partially embedded within the plastic body and extend into the reaction zone. Also contained within the reaction zone is an enzyme capable of catalyzing a reaction involving a compound within the fluid sample. Additionally, the sensor incorporates fill detection which activates a meter, attached to the sensor, for measuring the electrochemical changes occurring in the reaction zone.

Abstract: An improved electrochemical sensor having a base bearing a working and counter electrode which provides a flow path for a fluid test sample. The working and counter electrodes are configured so that a major portion of the counter electrode is located downstream on the flow path from the working electrode with the exception of a small sub-element of the counter electrode which is in electrical communication with the primary portion of the counter electrode and located upstream of the working electrode. This configuration enables the sensor when the capillary space is incompletely filled with test fluid.

Abstract: A disposable biosensor for testing a fluid sample including a laminated strip with a first and second end, a reference electrode embedded in the laminated strip proximate to the first end, at least one working electrode embedded in the laminated strip proximate to the first end and the reference electrode, an open path for receiving a fluid sample beginning from the first end and connecting to a vent spaced from the first end, the open path being sufficiently long to expose the reference electrode and the working electrode to the fluid sample, and conductive contacts located at the second end of the laminated strip. The laminated strip has a base layer with a conductive coating, a reagent holding layer, a channel forming layer and a cover having an inlet notch at the first end. The working electrode contains a reagent having an enzyme.

Abstract: A biosensor having an electrode layer, which includes a working electrode and a counter electrode, and a reagent layer 10 are formed on an insulating support. Further, a spacer having a long and narrow cut-out portion on the reagent layer is bonded to a cover having an air hole to form a cavity that sucks blood as a liquid sample by capillary phenomenon, and a portion of side walls of the spacer and the cover, which side walls face the cavity, is subjected to a treatment for making the portion itself have hydrophilicity. Accordingly, when blood is sucked into the cavity by capillary phenomenon, the suction is promoted, and the performance of a sensor of the biosensor is improved. Further, the process of manufacturing the sensor is simplified, thereby resulting in increased productivity.

Abstract: The present invention relates to technology for constructing a reaction system including a test target, an oxidation-reduction enzyme, and an electron mediator, and measuring the concentration of the test target by an electrochemical process. A Ru compound is used as the electron mediator. The present invention provides a concentration test instrument including a substrate, first and second electrodes formed on the substrate, and a reagent layer formed as a solid. The reagent layer contains an oxidation-reduction enzyme and a Ru compound, and is constituted so as to dissolve and construct a liquid phase reaction system when a sample liquid is supplied.

Abstract: Disclosed is a highly responsive biosensor comprising a cholesterol-oxidizing enzyme and cholesterol esterase. The biosensor comprises: an electrically insulating base plate; an electrode system including a working electrode and a counter electrode formed on the base plate; a cover member joined with the base plate to define a sample supply pathway through which a sample solution is introduced from a sample supply port to the electrode system, the sample supply pathway being formed between the cover member and the base plate; and a reagent layer formed in the sample supply pathway, wherein the reagent layer contains a cholesterol-oxidizing enzyme, cholesterol esterase, an electron mediator, and a buffer having a buffering capacity in an acidic pH range.

Abstract: A biosensor is provided that comprises a substrate, a reagent positioned on the substrate, and a cover including a top side and a generally flat bottom side. The bottom side is coupled to the substrate to define a sealed portion and an unsealed portion. The unsealed portion cooperates with the substrate to define a channel extending across the reagent.

Abstract: An electronic circuit for sensing an output of a sensor having at least one electrode pair and circuitry for obtaining and processing the sensor output. The electrode pair may be laid out such that one electrode is wrapped around the other electrode in a U-shaped fashion. The electronic circuitry may include, among other things, a line interface for interfacing with input/output lines, a rectifier in parallel with the line interface, a counter connected to the line interface and a data converter connected to the counter and the electrode pair. The data converter may be a current-to-frequency converter. In addition, the rectifier may derive power for the electronic circuit from communication pulses received on the input/output lines.

Abstract: Electrochemical biosensor test strip, fabrication method thereof and electrochemical biosensor are disclosed. The electrochemical biosensor test strip is fabricated by cutting a groove in a first insulation base in the breadth direction, forming two electrodes parallel to length direction on the first insulation base by sputtering using shadow mask, fixing a reaction material comprising an enzyme which reacts an analyte and generates current corresponding to the concentration of analyte across the two electrodes on the groove of the insulation base, and affixing a cover to the first insulation base. The groove of the first insulation base and the cover make a capillary at the position where the reaction material is fixed. The fabrication method can lower the cost for fabricating the test strip by forming thin electrodes.

Abstract: A method of making a biosensor is provided. The biosensor includes an electrically conductive material on a base and electrode patterns formed on the base, the patterns having different feature sizes. The conductive material is partially removed from the base using broad field laser ablation so that less than 90% of the conductive material remains on the base and that the electrode pattern has an edge extending between two points.

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: The present invention relates to biosensors having improved sample application and measuring properties and their uses for detection, preferably, quantitative measurement, of analyte in a liquid sample. In particular, the invention provides for a biosensor having a sample application and reaction chamber facilitating the speed and uniformity of sample application, especially small volume sample application, via capillary flow. The invention also provides for a biosensor having multiple circuits that lead to improved assay consistency and accuracy. Methods for assaying analytes or enzymes using the biosensors are further provided.

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 spacer forming method for a biosensor that has a biosensor possessing a capillary sampling channel and electrical connecting tracks for the use of a specific portable meter. A pair of electrodes is printed on an insulating base plate to be the transducer of the electrochemical biosensor by means of the screen-printing technology. The advanced thick-film printing technology is employed to construct the spacer component of the sampling channel that precisely controls the volume of a sample solution. Therefore, the spacer forming method reduces the usage of adhesive that otherwise causes a serious problem during a continuous punching procedure. Furthermore, the embedded switch pad on the biosensor is introduced to be instead of a micro switch in a connector of the portable meter.

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 provides a high performance glucose sensor which can demonstrate high stability against preservation and produces only a low blank value. The glucose sensor comprises an electrically insulating base plate, an electrode system formed on the base plate, and a reaction layer which is formed in contact with or in the vicinity of the electrode system and contains at least a glucose dehydrogenase whose coenzyme is pyrrolo-quinoline quinone, the reaction layer further containing an additive such as phthalic acid.

Abstract: The present invention relates to an enzyme electrode useful for estimation of cholesterol in aqueous medium, said electrode comprising:

Abstract: A biosensor is provided in accordance with the present invention. The biosensor includes an electrode support substrate, electrodes positioned on the electrode support substrate, a sensor support substrate coupled to the electrode support substrate, and electrically conductive tracks positioned on the sensor support substrate. Each track is in electrical communication with one of the electrodes.

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: Disclosed is an improved electrode for use in an electrochemical sensor for measuring an analyte in a sample. The electrode includes a thin working layer whose thickness is from 2 to 10 microns. Also disclosed is an electrode strip that includes an electrode with a thin working layer. Typically, the thin working layer includes an enzyme and a redox mediator. In an electrode for measuring glucose, the enzyme can be glucose oxidase and the redox mediator can be ferrocene.

Abstract: A sensing apparatus comprising an ion sensitive field effect transistor arranged to generate an electrical output signal in response to localised fluctuations of ionic charge at or adjacent the surface of the transistor, and means for detecting the electrical output signal from the ion sensitive field effect transistor, the localised fluctuations of ionic charge indicating events occurring during a chemical reaction.

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.

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.