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. The test device electrodes can be constructed on a flexible film substrate, such as a polymeric film or a metal foil coated with a non-conductive coating.

Abstract: A redox polymer for use in an electrochemical-based sensor includes a hydrophobic polymer backbone (e.g., a hydrophobic poly(methyl methacrylate) polymer backbone) and at least one hydrophilic polymer arm (such as a hydrophilic oligo(N-vinylpyrrolidinone) polymer arm) attached to the hydrophobic polymer backbone. The redox polymer also includes a plurality of redox mediators (e.g., ferrocene-based redox mediators) attached to the at least one hydrophilic polymer arm.

Abstract: A process for the examination of biocompartments (1), having a micro-flow chamber (2) which contains a biocompartment (1) which is continually or intermittently subjected to the through-flow of a culture medium. In a culture medium zone proximal to the biocompartments (1), an electrical potential is applied in such a manner, that from a substance in the culture medium which is released or consumed by the biocompartments (1), OH? and/or H+ ions are formed. During the application of the potential, a first measurement (pH?1, pH?3) for the pH value of the culture medium is measured. The potential is then switched off or changed in such a manner that the formation of OH? and/or H+ ions from the said substance is stopped. Before or after the measuring of the first measured value, (pH?1, pH?3) with switched off electrical potential, a second measured value (pH?2, pH?4) is measured for the pH value of the culture medium.

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. The test device electrodes can be constructed on a flexible film substrate, such as a polymeric film or a metal foil coated with a non-conductive coating.

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

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: A polymer composition is provided, which contains a polymer or copolymer having a mercapto group at one end and functional group or ligand at the other end and also having a polyethylene glycol segment. Such a composition can form a biosensor surface of reduced non-specific adsorbability for proteins and the like.

Abstract: The present invention relates to a biosensor for the detection and/or the determination of freshness biomarkers, such as biogenic amines (preferably histamine) in food and beverage, comprising an electrode and a mono-enzyme system, such as an amine oxidase, or a bi-enzyme system of an amine oxidase and a peroxidase. The enzymes are optionally crosslinked into an osmium based redox polymer.

Abstract: A sensor for the detection of tetrameric multivalent neuraminidase within a sample is disclosed, where a positive detection indicates the presence of a target virus within the sample. Also disclosed is a trifunctional composition of matter including a trifunctional linker moiety with groups bonded thereto including (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, the recognition moiety capable of binding with tetrameric multivalent neuraminidase.

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 three or four-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 is 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 (third layer). An outer (fourth) layer is biocompatible.

Abstract: The present invention generally relates to a method for producing biosensors and a biosensor for determination of creatinine. The biosensor comprises at least two enzymes, for the amperometric determination of enzymatically degradable substances in biological liquids, the enzymes being immobilized on a working electrode.

Abstract: Hydrogels containing catalase co-immobilized with an analyte-sensitive enzyme such as glucose oxidase are disclosed. The hydrogels may be pH-sensitive, and preferably are thin and lightly crosslinked. The catalase is present in concentrations ranging generally from 100 units/ml to about 1000 units/ml. These hydrogels have much faster swelling response times as compared to hydrogels without catalase, and are useful in biosensors and analyte-responsive drug delivery devices. The hydrogels also have an increased useful life, due to protection of the immobilize analyte-sensitive enzyme from degradation by hydrogen peroxide.

Abstract: The invention is directed to compositions of mutated binding proteins containing reporter groups, analyte biosensor devices derived there from, and their use as analyte biosensor both in vitro and in vivo.

Abstract: A system for detecting physical or chemical changes in an environment is disclosed. The system comprises means for conducting a chemical reaction; an active biological molecule whose physiological function is noncatalytic which is capable of catalyzing a chemical reaction wherein at least one reactant is converted to one product; and means for sensing and processing information relating to changes in said environment. A method for detecting physical or chemical changes in an environment is also disclosed.

Abstract: The use of impedance measurements to detect the presence of pathogens attached to antibody-coated beads. In a fluidic device antibodies are immobilized on a surface of a patterned interdigitated electrode. Pathogens in a sample fluid streaming past the electrode attach to the immobilized antibodies, which produces a change in impedance between two adjacent electrodes, which impedance change is measured and used to detect the presence of a pathogen. To amplify the signal, beads coated with antibodies are introduced and the beads would stick to the pathogen causing a greater change in impedance between the two adjacent electrodes.

Abstract: A conductive microplate device for the detection of target biomolecules in a sample is described. The microplate comprises an assembly of a porous substrate and a conductive layer, wherein the assembly is sealed into bottom of at least some wells of the microplate. The porous substrate has a top surface and a bottom surface. The top surface comprises a plurality of covalently attached probe biomolecules. The covalently attached probe biomolecules are reactive with the target biomolecules contained in the sample. The conductive layer, which is attached to the bottom surface of the porous substrate, is adapted to receive voltage. Microplates of the present invention can be easily adapted for use with robotic workstations. Accordingly, in one embodiment, the power supply is incorporated into a robotic arm tool for fast microplate processing.

Abstract: The use of impedance measurements to detect the presence of pathogens attached to antibody-coated beads. In a fluidic device antibodies are immobilized on a surface of a patterned interdigitated electrode. Pathogens in a sample fluid streaming past the electrode attach to the immobilized antibodies, which produces a change in impedance between two adjacent electrodes, which impedance change is measured and used to detect the presence of a pathogen. To amplify the signal, beads coated with antibodies are introduced and the beads would stick to the pathogen causing a greater change in impedance between the two adjacent electrodes.

Abstract: Improved biosensors are provided having excellent selectivity and stability properties, together with methods of preparing the biosensors. A preferred biosensor includes an electrode (12) having enzyme (16) deposited thereon together with a layer of electropolymerized polymer (18) intermingled with the enzyme (16); a crosslinked silane film (20) is applied over the polymer layer (18), and a final coating (22) of polyurethane is formed over the film (20). In preparative procedures, the enzyme (16) is electrodeposited using an aqueous enzyme solution containing a nonionic surfactant at a concentration level preferably in excess of the critical micelle concentration of the surfactant. In the case of a glucose sensor, the polymer layer (18) is preferably polyphenol, while the silane film is crosslinked (3-aminopropyl) trimethoxysilane. The preferred biosensors have greatly enhanced selectivity stabilities.

Abstract: The present invention relates to a biosensor which comprises a covalently attached monomolecular biological conjugate layer and a transducing system, wherein the biological conjugate layer has the following structural formula I: —R—X—P  I wherein, R is O or S covalently attached via a first covalent bond to the transducing device surface; X is a linker covalently attached to R via a second covalent bond and selected from a bond, linear or branched chains of 1 to 30 covalently attached atoms of at least C, N, O, Si or S, rings of at least one of C, N, O, Si or S, and a combination thereof; and P is a biological molecule stably attached to X via a third covalent bond.

Abstract: The present disclosure relates to a method for determining cholesterol in low density lipoprotein comprising the steps of (a) measuring total cholesterol level in a sample containing at least high density lipoprotein, low density lipoprotein, very low density lipoprotein and chylomicron, and (b) measuring cholesterol levels in the high density lipoprotein, very low density lipoprotein and chylomicron in the sample, wherein the cholesterol level in the low density lipoprotein is determined by subtracting a value obtained in the step (b) from a value obtained in the step (a). The present invention enables concurrent determination of cholesterol level in low density lipoprotein and total cholesterol level, facilitating acquisition of two types of biological information at a time.

Abstract: A device and method are provided using a sensor containing an electrode with an enzyme layer to determine a component in a liquid sample. Inlet and outlet channels feed liquid sample to and from the sensor surface. The inlet channel is placed an angle of preferably 1 to 80 degrees to the sensor surface, and an inlet channel end opening is at a distance from the sensor surface of preferably two fold or less of an inlet channel inner diameter. The angle and distance provide good measurement accuracy, stable measurement sensitivity and rapid response. The sensor may be vertically sandwiched between upper and lower parts, and be removable from the upper part. Liquid sample is continuously moved from the inlet channel over the sensor surface and discharged through the outlet channel. Liquid sample speed over the sensor surface is adjusted to provide sensor output in proportion to concentration of the liquid.

Abstract: Apparatus comprising G-protein coupled receptor (GPCR) for detecting ligands or substances in liquid or vapor media. The GPCR is based on in a cell or in a synthetic membrane or polymer system, and combined with means for obtaining a sample of a liquid or vapor medium, and with automatic optical detection system and monitoring system for detecting a ligand of interest. Methods are disclosed for detecting a ligand of interest using the GPCR apparatus.

Abstract: The invention relates generally to methods, systems, and devices for measuring the concentration of target analytes present in a biological system using a series of measurements obtained from a monitoring system and a Mixtures of Experts (MOE) algorithm. In one embodiment, the present invention describes a method for measuring blood glucose in a subject.

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: Rapid electrochemical verification of the amplification of DNA by a polymerase chain reaction in a small sample of the PCR product.

Abstract: A sensor for the detection of tetrameric multivalent neuraminidase within a sample is disclosed, where a positive detection indicates the presence of a target virus within the sample. Also disclosed is a trifunctional composition of matter including a trifunctional linker moiety with groups bonded thereto including (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, the recognition moiety capable of binding with tetrameric multivalent neuraminidase.

Abstract: The present invention provides a novel biosensor for the detection of chemicals of interest. The novel biosensor of the present invention comprises an electrode having a catalytically active cyclodextrin attached thereto. The present invention will be useful for the detection of materials in a wide variety of samples. In particular, the present invention will permit the detection of nitrophenyl esters.

Abstract: The present invention provides an inexpensive and sensitive device and method for detecting and quantifying analytes present in a medium. The device comprises a metalized film upon which is printed a specific, predetermined pattern of an antibody-binding proteins. Upon attachment of a target analyte to select areas of the plastic film upon which the protein is printed, diffraction of transmitted and/or reflected light occurs via the physical dimensions and defined, precise placement of the analyte. A diffraction image is produced which can be easily seen with the eye or, optionally, with a sensing device.

Abstract: One embodiment of the invention is a method for obtaining an estimate of an analyte concentration in a first fluid. First, measurements of an analyte concentration in a second fluid are obtained using a sensing device. An analyte concentration estimate in the first fluid is determined from these measurements by minimizing the relation: f[b]=x2[b]+&lgr;&PSgr;[b], where b is a vector representing analyte concentration in the first body fluid, X2[b] is a function representing a fit between the estimates and the measurements, &lgr; is a weighting function, and &PSgr;[b] is a function indicating smoothness of the analyte concentration estimates in the first fluid. Another embodiment includes a sensing device for obtaining the measurements of an analyte concentration in the first fluid and a processor configured and arranged to determine the analyte concentration in the first body fluid according to this method.

Abstract: The present invention relates to a filtration-detection device for detecting or quantifying an analyte in a test sample including a filtration device having a first binding material immobilized thereto, wherein the first binding material is capable of binding to a portion of the analyte, and a detection assembly positioned relative to the filtration device to detect or quantify analyte bound to the first binding material. The present invention also relates to methods of using the filtration-detection device.

Abstract: The present invention relates to a membrane for use in detecting the presence of an analyte. The membrane comprises an array of closely packed self-assembling amphiphilic molecules and a plurality of first and second receptor molecules, the first receptor molecules being reactive with one site on the analyte and second receptor molecules being reactive with another site on the analyte. The first receptor molecules are prevented from lateral diffusion within the membrane whilst the second receptor molecules are free to diffuse laterally within the membrane. The membrane is characterized in that the ratio of first receptor molecules to second receptor molecules is 10:1 or greater.

Abstract: The micelle contains multiple units, each of which contains a hydrophobic part and a hydrophilic part. A preferred unit is dodecyl benzene sulfonic acid. Borate-containing electrolytes include trifluoroborate, trimethylborate and hydrobis(pyridine)boron. Enzymes include peroxidases such as horseradish peroxidase or lignin peroxidase, and laccase. Monomers include unsubstituted and substituted anilines and unsubstituted and substituted phenols. A method is provided for enzymatic polymerization which includes (1) obtaining a reaction mixture including a monomer, a template, and an enzyme; and (2) incubating the reaction mixture for a time and under conditions sufficient for the monomer to align along the template and polymerize to form a polymer-template complex. The template can be a micelle, a borate-containing electrolyte, or lignin sulfonate.

Abstract: An electronic controller, such as a programmed microcontroller (33), controls a series of pumps (P1-P6) to automatically sequence the pumping of the individual fluids required by the ELISA procedure into a cell (or cells) necessary to produce a reporter, control the positioning of the carrier of the reporter (32, 35) adjacent the reporter sensor (28), analyze the data obtained from the reporter sensor and display (36) the concentration of the bioagent determined from the analysis of the foregoing data. The foregoing elements automate the ELISA procedure. Once started, the apparatus, governed by the program, conducts the test automatically without the necessity for human intervention. In accordance with a specific aspect, the foregoing components may be housed in a single package for easy portability; may be battery powered or line powered.

Abstract: A reagent and method for determining the levels of 3-hydroxybutyric acid in a sample are provided. The reagent comprises a ferricyanide salt, a catalytic amount of a first enzyme operative to catalyze the oxidation of 3-hydroxybutyric acid in the sample, a cofactor corresponding to said first enzyme, and a catalytic amount of a second enzyme operative to catalyze the oxidization of the cofactor and the reduction of the ferricyanide. The reagent is incorporated into a test strip that generates an electrical output signal indicative of the level of 3-hydroxybutyric acid when the reagent is contacted with a sample.

Abstract: The present invention relates to a glucose biosensor comprising a genetically engineered Glucose Binding Protein (GBP). In a specific embodiment, the invention relates to a GBP engineered to include mutations that allow site specific introduction of environmentally sensitive reporter groups. The signal of these prosthetic groups changes linearly with the degree of glucose binding. Thus, the glucose sensor of the invention can be used, for example, for detection of glucose in blood or industrial fermentation processes.

Abstract: The present invention relates to a biosensor. The biosensor includes a support substrate having first and second ends, electrodes positioned on the support substrate, the electrodes cooperating with one another to define electrode arrays situated adjacent to the first end, a spacer substrate positioned on the support substrate, and a cover positioned on the spacer substrate. The cover cooperates with the support substrate to define a channel. The channel includes an inlet adjacent to the first end and opposite ends. Each electrode array is positioned in the channel adjacent to one of the ends.

Abstract: The present invention concerns class II cytochrome P450s, electrochemical systems for assaying cytochrome P450 catalytic activity, apparatus and methods for same.

Abstract: The present invention relates to a biosensor (affinity sensor) in which a hydrogel, a surfactant layer or biotin are bonded to the biosensor's precious metal surface by means of a short-chained linker, as well as to the process for the preparation thereof. A complete covering of the biosensor surface with the hydrogel, the surfactant layer or the biotin is achieved by hydrogen bonds, aromatic-aromatic interactions or by covalent bonds.

Abstract: A microbial membrane reactor for use in flow systems comprises a first element to receive the microorganisms and a second element to receive the flow channels. The two elements have planar interior surfaces which are pressed together separated by a membrane impervious to the microorganisms. The flow channels arranged in or on the surface of the second element serve to transport the liquid along the membrane so that the liquid can interact with the microorganisms arranged on the other side of the membrane. The geometry of the flow pathway and thus the geometry of the flow channels can be easily altered, in respect of the length, width and height of the channel, and adapted to practical requirements.

Abstract: An immunoassay method including reacting a sample from a patient with a bispecific antibody, wherein the bispecific antibody includes one antibody specific for a compound to be detected and a second antibody specific for a compound foreign to said patient sample, and subsequently reacting the patient sample with a polymer probe, wherein the polymer probe includes a compound recognized by the second antibody in the bispecific antibody complex and further includes at least two detectable signals; the bispecific antibody; and the polymer probe of the immunoassay method are disclosed.

Abstract: A linker lipid for use in attaching a membrane including a plurality of ionophores to an electrode and providing a space between the membrane and the electrode in which the membrane is either in part or totally made up of the linker lipid. The linker lipid has within the same molecule a hydrophobic region capable of spanning the membrane, an attachment group used to attach the molecule to an electrode surface, a hydrophilic region intermediate the hydrophobic region and the attachment group, and a polar head group region attached to the hydrophobic region at a site remote from the hydrophilic region. The attachment group has a cross sectional area greater than the cross sectional area of the hydrophilic region, and has the structure recited in the specification.

Abstract: Microfluidic devices for analyzing a plurality of compounds are manufactured for performing high throughput screening assays. The methods are used to manufacture devices that screen large numbers of different compounds for their effects on a variety of chemical and biochemical systems.

Abstract: The present disclosure relates to a method for determining cholesterol in low density lipoprotein comprising the steps of (a) measuring total cholesterol level in a sample containing at least high density lipoprotein, low density lipoprotein, very low density lipoprotein and chylomicron, and (b) measuring cholesterol levels in the high density lipoprotein, very low density lipoprotein and chylomicron in the sample, wherein the cholesterol level in the low density lipoprotein is determined by subtracting a value obtained in step (b) from a value obtained in step (a). The present invention enables concurrent determination of cholesterol level in low density lipoprotein and total cholesterol level, facilitating acquisition of two types of biological information at a time.

Abstract: A microbial membrane reactor for use in flow systems comprises a first element to receive the microorganisms and a second element to receive the flow channels. The two elements have planar interior surfaces which are pressed together separated by a membrane impervious to the microorganisms. The flow channels arranged in or on the surface of the second element serve to transport the liquid along the membrane so that the liquid can interact with the microorganisms arranged on the other side of the membrane. The geometry of the flow pathway and thus the geometry of the flow channels can be easily altered, in respect of the length, width and height of the channel, and adapted to practical requirements.

Abstract: High-throughput screening method and apparatus are described. The method includes placing cells on a substrate defining a plurality of discrete microwells, at a well density of greater than about 100/cm2, with the number of cells in each well being less than about 1000, and where the cells in each well have been exposed to a selected agent. The change in conductance in each well is determined by applying a low-voltage, AC signal across a pair of electrodes paced in that well, and synchronously measuring the conductance across the electrodes, to monitor the level of growth or metabolic activity of cells contained in each well. Also disclosed is an apparatus for carrying out the screening method.

Abstract: The present invention provides a biosensor for use in detecting the presence of an enzyme or enzymes in a sample. The biosensor comprises a membrane and means for determining the impedance of the membrane. The membrane includes ionophores therein to which are attached linkers. The linkers are cleavable by the enzyme or enzymes to be detected, with the cleavage of the linker causing a change in the ability of ions to pass through the membrane via the ionophores.

Abstract: The present invention relates to an apparatus to perform reagent-free assays, which apparatus utilizes an all solid probe having an enzyme label that acts on a substrate by obtaining electrons directly from the electrode by bioelectrocatalysis.

Abstract: Electrode membrane combinations for use in biosensors to detect analytes in a sample and methods for making and storing same are disclosed. In one aspect, a method is provided for producing a first layer electrode membrane comprising: (1) Forming a solution containing Linker Lipid A, the disulfide of mercaptoacetic acid (MAAD) or similar molecule, linker Gramicidin B, membrane spanning lipid C (MSL-C) and membrane spanning lipid D (MSL-D) or other suitable linker molecules and other ion channel combinations; (2) Contacting an electrode containing a clean gold surface with the solution, the disulfide containing components in the solution thus adsorbing onto the gold surface of the electrode; (3) Rinsing the electrode with a suitable organic solvent; and (4) Removing the excess organic solvent used for rinsing.

Abstract: The present invention provides a sensor that electrochemically determines cholesterol in low density lipoprotein by only one feed of a sample. The sensor has: an electrode system that is mounted on an electrically insulating base plate and includes at least a working electrode and a counter electrode; an enzyme layer formed on the base plate with the electrode system; and a reagent layer that is arranged before the enzyme layer in a sample solution supply path to the electrode system. The enzyme layer includes at least an oxidoreductase and an electron mediator. The reagent layer includes a reagent that depresses reactivity of cholesterol in lipoproteins other than the low density lipoprotein with the oxidoreductase, for example, a reagent that attaches to lipoproteins other than the low density lipoprotein to form a water-soluble complex.

Abstract: A sensor for detecting analytes is described. Analyte presence or concentration is determined through measurement of changes in induced electromotive force, current or other electrical property in a base member during analyte exposure to the sensor. According to one class of embodiments, the present device immobilizes natural or synthetic macromolecules sufficiently close to an electrically-conductive base member to insure that any alteration in the motion and/or electrostatic fields of the macromolecules during interaction with a predetermined analyte will induce an increased electromotive force in the base member.