Abstract: An enzyme electrode having excellent sensitivity, excellent stability, and a longer operating life, and an enzyme sensor using the enzyme electrode are provided. The enzyme electrode includes an electrode 2, a mesoporous silica material 3 formed on the electrode 2, and enzyme 4 immobilized in a small cavity of the mesoporous silica material 3. The size of the small cavity of the mesoporous silica material 3 is set to be 0.5 to 2.0 times the size of the enzyme 4.

Abstract: The present invention provides reagent compositions, and analyte measuring devices and methods that utilize the reagent compositions.

Abstract: The instant invention is about a microelectrode, in particular for measuring the concentration of a D-amino acid, said microelectrode comprising means for oxidation of said D-amino acid into at least a compound B, means for optimising the detection of said compound B, and means for reducing interferences, in particular interferences due to the oxidation of other species than compound B; a device comprising such a microelectrode; a method for making such a microelectrode, a method for detecting and/or measuring the concentration of a D-amino-acid in a medium.

Abstract: This invention relates to a sensor for detecting an analyte in the presence of at least one interferent in a fluid sample. The sensor comprises a substrate, a channel disposed on the substrate, at least one transducer disposed in the channel, and a filter for selectively absorbing the analyte in preference to the at least one interferent. The filter is arranged in the channel remotely from the at least one transducer and the channel defines a flow path for the fluid sample such that the fluid sample contacts a first transducer to generate a first signal, followed by the filter, followed by the first transducer or a second transducer to generate a second signal.

Abstract: Disclosed herein is an electrochemical sensor for measuring an analyte in a subject. More particularly, sensors comprising a polyelectrolyte layer at least partially covering the electroactive surface of an electrode are disclosed.

Abstract: The present invention relates to a new hydrogel functionalized with a polymerizable moiety, the polymerized hydrogels, films and gels comprising the same and their use for cells, proteins, DNA or other molecules encapsulation, including use as biosensors or bioreactors.

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

Abstract: A test strip having a small sample-receiving chamber on the order of less than 1 microliter. The inventive test strip includes a reagent layer that extends across the width of the test strip and also extends to the sample-receiving end, such that the edges of the reagent layer are aligned with the side and dose receiving edges of the test strip. The hydrophilic reagent extending to the dosing edge of the strip promotes wicking of the sample into the test strip. The end and side edges of the reagent layer are preferably formed as part of a cutting process that forms individual test strips from a larger web, which results in a smooth and thin reagent layer with a uniform thickness, substantially covering the entire floor of the sample-receiving chamber. The inventive mass production process helps improve the reproducibility of the quantity, location, thickness and other properties of the reagent layer, which in turn improves the accuracy of the test result.

Abstract: The present invention relates to a method for measuring the concentration of a particular component in a blood sample containing blood cells based on a variable correlated with the concentration of the particular component. In the present invention, a concentration (S) in blood plasma obtained by removing blood cell components from the blood sample, a concentration (DI) in the blood sample computed by a differential method and a concentration (EP) in the blood sample computed by an equilibrium point method are expressed by a relational expression which is unrelated to the proportion of the blood cell components in the blood sample, and the concentration of the particular component is computed by using the relational expression.

Abstract: Disclosed is a device for detecting bioelectric signals from spheroids comprising a measuring chamber having a measuring chamber wall which encloses a volume, which is open at least at one side, is composed of an electrically non-conducting material, and has, in at least one measuring region, an inner cross section, which corresponds as far as possible to the largest cross section of a spheroid, comprising at least a number of electrodes which are disposed in a common plane inside said measuring chamber wall and each electrode has a freely accessible electrode surface which is oriented towards the measuring region, and comprising an impedance measuring arrangement which is connected to the electrodes. The device and the method can be used to test substances in 3D biological in-vitro (three-dimensional) cell aggregates.

Abstract: A potentiometric sensor, especially a pH-sensor or redox-sensor, includes: an elementary sensor for registering a potentiometric parameter, especially a pH-value or a redox potential; and an interface for issuing a potentiometric-parameter-dependent signal to a superordinated unit, especially a transmitter; wherein the potentiometric sensor of the invention has a digital data memory, which is permanently connected with elementary sensor.

Abstract: A method of derivatising an analyte for subsequent detection through a nucleic acid based sensor and a sensor based thereon.

Abstract: A sensing apparatus comprising an ion sensitive field effect transistor arranged to generate an electrical output signal in response to localized 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 localized fluctuations of ionic charge indicating events occurring during a chemical reaction.

Abstract: Membranes useful for amperometric sensors are described. The membranes allow continuous and real time in vivo measurements of a variety of redox active chemical species present in a fluid sample. In some embodiments, the membrane comprises a redox mediator, a redox reactive species, and conductive nano structures, such as carbon nanotubes. The membrane can be provided on a working electrode of the sensor. Amperometric sensors incorporating the membranes and methods of treatment using the sensors are also described.

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 method and analyte-measurement device adapted to determine the concentration of an analyte in a fluid from a measurement site within a body, including an animal body, a mammalian body, or a human body. The invention further relates to the use of partially or fully implantable glucose-monitoring devices, including transcutaneous or subcutaneous glucose-monitoring devices. Devices, systems and kits making use of the aforementioned method are provided as well.

Abstract: The present invention relates generally to devices for measuring an analyte in a host. More particularly, the present invention relates to devices for measurement of glucose in a host that incorporate a cellulosic-based interference domain.

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 provides a test strip for measuring a concentration of an analyte of interest in a biological fluid, wherein the test strip may be encoded with information that can be read by a test meter into which the test strip is inserted.

Abstract: A connector for establishing electrical connection between a testing device and a test strip with a biological fluid thereon includes a contact pad on the test strip, and one or more contact wires in the testing device. When the strip is inserted into the testing device, the end of the strip engages with a bight in the contact wire, pushing the contact wire in a direction normal to the direction of insertion. The movement of the contact wire forces a second portion of the wire against a part of the housing, thereby deforming the wire and moving another portion of the wire toward the contact pad. Some embodiments of the invention include 4, 6, 8, 15, or more contacts, which may be situated so as to receive the end of the test strip substantially simultaneously, or may be staggered in 2, 3, or more rows to spread out the resistance to movement presented.

Abstract: A polymer matrix that may coated on an electrode is created by co-crosslinking (1) an adduct of a polyaniline formed by templated oxidative polymerization on a polymer acid; (2) a water-soluble crosslinker; and (3) a redox enzyme. The polymer matrix may be hydrated, and the absorbed water may make it permeable to, for example, glucose. The polyaniline may be polyaniline itself or a substituted polyaniline; the water-soluble crosslinker may be poly(ethylene glycol) diglycidyl ether, and the redox enzyme may be glucose oxidase. The polymer matrix may be produced by co-crosslinking (1) an adduct of an electrically conductive polymer and a polymer acid; (2) a water-soluble crosslinker; and (3) a redox enzyme in a single step at an about neutral pH, curing by drying. After hydration, the crosslinked polymer matrix may form a 3-dimensional glucose-permeable bioelectrocatalyst, catalyzing the electrooxidation of glucose.

Abstract: The present invention relates to a test instrument (X) including a capillary (5) for moving a sample liquid (B), a liquid pooling portion (4) communicating with the capillary (5) for retaining the sample liquid (B) to be introduced into the capillary (5), and a liquid introduction selector (12) for selecting whether or not the sample liquid (B) retained in the liquid pooling portion (4) is introduced into the capillary (5). The present invention also relates to an attachment provided with the test instrument (X), and a concentration measuring apparatus to which the attachment is mounted for use.

Abstract: Biosensor system and method for the electrochemical determination of an concentration of an analyte in a sample. An analyte reactant is at least partially hydrated by the sample to form a reaction layer in contact with electrodes for measurement of an analyte detection current. The analyte detection current is characteristic of the analyte concentration in the sample by virtue of a reaction sequence comprising an analyte-specific reaction taking place in the reaction layer and an electrode reaction including transfer of electrons through an electrode surface. A plurality of values of a curve of the analyte detection current versus time are measured and the analyte concentration is derived therefrom by means of an evaluation algorithm.

Abstract: A sensor including a sensing layer is disposed over an electrode or an optode and a layer-by-layer assembled mass transport limiting membrane disposed over the sensing layer. The membrane includes at least one layer of a polyanionic or polycationic material. The assembled layers of the membrane are typically disposed in an alternating manner. The sensor also optionally includes a biocompatible membrane.

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

Abstract: There is provided a biosensor in which a spacer 6 having a cutout portion is bonded between at least first support 1 and a second support 8 to form a specimen supply path 7 through which a supplied specimen is sucked into a space between the supports 1 and 8, a reagent that reacts with a component in the specimen is placed in the specimen supply path 7, and an air hole 9 for promoting suction of the specimen is formed in the second support; wherein the air hole 9 is shaped such that a diameter y of an opening 91b at one surface of the second support 8 which faces the specimen supply path 7 is larger than a diameter x of an opening 91a at the other surface of the second support, and projecting parts 92a and 92b are formed at the peripheries of the openings 91a and 91b, respectively. Thereby, a sufficient amount of specimen can be sucked regardless of the viscosity of the specimen supplied to the biosensor, and further, the specimen is prevented from flowing over the air hole 9.

Abstract: A sensor for sensing and measuring a concentration of urea in a sample has an ammonium ion selective membrane and urease enzymes immobilized on the ammonium ion selective membrane. The urease enzymes enzymatically convert urea into ammonium ions, which is sensed by said ammonium ion selective membrane and transformed into a signal. A detector system is used for processing signal from said ammonium ion selective membrane to generate a response potential that corresponds to the concentration of urea in the sample.

Abstract: The present invention provides a test strip for measuring a concentration of an analyte of interest in a biological fluid, wherein the test strip may be encoded with information that can be read by a test meter into which the test strip is inserted.

Abstract: An electrode comprising a conducting substrate for detecting species such as nitric oxide (NO), carbon monoxide (CO), oxygen (O2) and hydrogen (H2) and a polymer matrix formed from a first layer only or first and second layers with the second layer applied to the first. The matrix forms a permselective barrier. Each layer has a first pre-coat or first and second pre-coats. Each pre-coat may be formed by: depositing a liquid form of at least one halogenated polymer such as fluorinated or chlorinated polymers onto a substrate and allowing the material to dry. A liquid form of at least one halogenated polymer adheres the first and second layers to the substrate. The electrode allows for detection of the target species and allows real time in vivo measurements to be taken. Blood flow can also be monitored. An electrode bundle with electrodes for different target species is also provided.

Abstract: The subject invention provides new materials and methods for the efficient isolation and purification of stem cells. Specifically, conductive immunopolymers with stem cell specific antibodies can be used to remove stem cells from biological fluids.

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

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

Abstract: An electrochemical-based sensor includes an electrode with at least one electrode surface, a film disposed on the electrode surface, and a dialysis membrane disposed on the film. The film includes a redox enzyme and a hydrophilic redox polymer (i.e., a polymer with an attached redox mediator(s)). In addition, the dialysis membrane serves to entrap the redox polymer and redox enzyme in the vicinity of the electrode. Such entrapment is accomplished by employing a redox enzyme and a hydrophilic redox polymer of a sufficiently high molecular weight that they do not pass through the dialysis membrane.

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

Abstract: The invention is directed to enzyme immobilization compositions comprising: one or more enzymes, a humectant, an acrylic-based monomer, a water-soluble organic photo-initiator and a water-soluble acrylic-based cross-linker in a substantially homogeneous aqueous mixture. The invention is also directed to methods for forming sensors comprising such compositions and to apparati for forming arrays of immobilized layers on an array of sensors by dispensing such compositions onto a substrate.

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

Abstract: Electrochemical sensors for measuring an analyte in a subject are described. More particularly, devices for measurement of an analyte are disclosed incorporating a sensor comprising an enzyme layer in contact with an interference layer and a membrane comprising vinyl ester monomeric units covering at least a portion of the enzyme layer and at least a portion of the interference layer, the devices providing rapid and accurate analyte levels upon deployment.

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

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

Abstract: Disclosed herein is a device that functions as a glucose sensor. The device has a reference electrode; a counter electrode, a working electrode; an electrically conducting membrane; an enzyme layer; a semi-permeable membrane; a first layer of a first hydrogel in operative communication with the working electrode; the first layer of the first hydrogel being operative to store oxygen; wherein the amount of stored oxygen is proportional to the number of freeze-thaw cycles that the hydrogel is subjected to; and a second layer of the second hydrogel. Disclosed too is a method that comprises using periodically biased amperometry towards interrogation of implantable glucose sensors to improve both sensor's sensitivity and linearity while at the same time enable internal calibration against sensor drifts that originate from changes in either electrode activity or membrane permeability as a result of fouling, calcification and/or fibrosis.

Abstract: An immobilization carrier containing an electron acceptor compound is used in addition to glutaraldehyde and poly-L-lysine to immobilize an enzyme and an electron acceptor compound simultaneously to an electrode. For example, here are used diaphorase as the enzyme and 2-amino-3-carboxy-1,4-naphthoquinone (ACNQ) as the electron acceptor compound.

Abstract: The disclosure concerns a high efficiency electrochemical sensor with high signal yield for determining an analyte in a fluid medium comprising, at least one reference electrode, at least one working electrode having particles of an electrocatalyst in an electrode matrix, and an enzyme that is suitable for determining an analyte is selectively covalently bound to the particles of the electrocatalyst. The disclosure also describes a process for producing the electrochemical sensor and a method for determining an analyte in a fluid medium using the electrochemical sensor. have a high efficiency and thus achieve a high signal yield.

Abstract: An electrochemical test sensor for detecting the analyte concentration of a fluid test sample includes a base, a dielectric layer, a reagent layer and a lid. The base provides a flow path for the test sample having on its surface a counter electrode and a working electrode adapted to electrically communicate with a detector of electrical current. The dielectric layer forms a dielectric window therethrough. The reagent layer includes an enzyme that is adapted to react with the analyte. The lid is adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of the test sample thereto. At least a portion of the width of the counter electrode is greater than the width of the working electrode.

Abstract: A new structure having mesopores is provided. The present invention provides a structure that has a plurality of mesopores wherein the structure has a dendritic framework and mesopores passing through the framework in the direction intersecting the longitudinal direction of the framework. The present invention also provides a porous material, a sensor and a method for detecting a specimen that take advantage of the new structure.

Abstract: An electrochemical sensor is provided that exhibits improved adhesion of the membrane to the nitride layer used as an insulating layer in silicon- or silicon-oxide-based electrochemical sensing devices. The sensing devices include a substrate, an oxide disposed on the substrate, a nitride disposed on the oxide, an electrically conductive structure disposed on the oxide layer, and an electrode disposed on the oxide layer and electrically coupled to the electrically conductive structure. At least one opening is formed in the nitride layer to form at least one adhesion trench that exposes a surface region of an oxide layer underlying the nitride layer. The membrane covers the electrode, and contacts the oxide surface regions exposed by the adhesion trenches. The contact between the membrane and the oxide surface region provides for improved adhesion of the membrane to the electrochemical sensing device.

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

Abstract: An apparatus for performing a binding assay for an analyte of interest present in a sample based upon measurement of electrochemiluminescence at an electrode surface comprising a cell defining a sample containing volume intersecting with inlet and outlet means, an electrode having a substantially horizontally positioned surface exposed to and positioned below a portion of the sample containing volume, means for impressing electrochemical energy upon said electrode sufficient to generate luminescence, means for magnetically collecting particles along said surface and means for measuring the luminescence generated at said electrode.

Abstract: A ruthenium oxide electrode. The ruthenium oxide electrode includes a substrate, a ruthenium oxide film formed thereon, and a conductive wire connecting to the ruthenium oxide film. The invention also provides a method of fabricating the ruthenium oxide electrode.

Abstract: Plasmons on a waveguide may deliver energy to photocatalyze a reaction. The waveguide or other energy carrier may be configured to carry electromagnetic energy and generate plasmon energy at one or more locations proximate to the waveguide, where the plasmon energy may react chemically with a medium or interaction material.

Abstract: An analyte test sensor for use in measuring the concentration of a particular analyte in a test sample includes a non-conductive substrate, a reference electrode deposited on the substrate, a working electrode deposited on the substrate and a compensation electrode deposited on the substrate. The compensation electrode is provided with a resistive ladder and is designed to correct for test result inaccuracies which are the result of variances in the manufacturing of the test sensor. Specifically, in one embodiment, the compensation electrode corrects for test result inaccuracies in an analog manner by shunting a portion of the working current away from working electrode. In another embodiment, the compensation electrode corrects for test result inaccuracies in a digital manner by providing a calibration code which is proportional its resistance value. A batch of analyte test sensors are preferably manufactured in the following manner. An initial batch of the test sensors is constructed.

Abstract: This electrodeless high intensity discharge lamp including a light-transmissive arc tube having spaced wall portions of dielectric material and a first gaseous fill within the arc tube. An excitation coil about the arc tube is energizable with RF current effective to develop a toroidal arc discharge in the first gaseous fill upon a dielectric breakdown of the fill. A starting container is joined to the arc tube and has an end wall constituted by one of said arc-tube wall portions. A second gaseous fill within the starting container has a dielectric strength lower than that of the first gaseous fill. For initiating the rotoidal arc discharge, we provide an arrangement for producing a dielectric breakdown of the gaseous fill within the starting container that develops into an electric discharge that changes the potential at the end wall in such a manner as to cause a dielectric breakdown of the first gaseous fill.