Abstract: A monitor is disclosed for monitoring an atmosphere for the presence of a target gas. The monitor includes an electrical gas sensor having a working (sensing) electrode and a counter electrode, an operational amplifier connected between the sensor electrodes, a detector, and a circuit. The sensor provides a current between the electrodes that is indicative of the amount of a target gas in the atmosphere. The operational amplifier generates an output signal according to the current flowing between the terminals where the output signal is indicative of the amount of target gas in the atmosphere. The detector detects when the current flowing between the sensor electrodes exceeds a predetermined threshold. The circuit restricts the potential difference between the sensor electrodes when the current between the terminals exceeds the predetermined threshold by supplying additional current or removing current from the working sensor electrode.

Abstract: Measurements of current from a working electrode and current from a blank electrode are received and a ratio corresponding to the ratio of surface areas of the working electrode and the blank electrode is determined. This ratio is used to correct any differential current offset between an analyte (working) electrode and a control (blank) electrode to yield a more accurate net current output. Systems, methods and computer program products are further described for measuring an analyte concentration disclosed are for calculating the amount of an analyte in a fluid using a biosensor.

Abstract: A method of extracting hormones from a biological sample using digital microfluidic arrays is provided. Biological samples containing hormones are dried on a digital microfluidic array, lysed by a lysing solvent, dried, subsequently dissolved in a polar solvent, and further purified in an extraction step in which droplets are transported through a volume of non-polar solvent. The method disclosed herein provides the distinct advantage of an automated sample preparation method that is capable of extracting hormones from low sample volumes with excellent precision and recovery.

Abstract: A systems and apparatus for measuring non-electroactive materials in liquids using electrochemical detection. A first electrical activity of a electroactive material is detected in absence of a target non-electroactive material (Step 120). A second electrical activity of the electroactive material is detected in presence of the target non-electroactive material (Step 130). A difference between the first and second electrical activities is obtained, and based on the obtained difference, a concentration of the target non-electroactive material is identified (Step 140).

Abstract: In a procedure to recognize the gas composition of a gas mixture, which consists of at least two gases of preferably different diffusion properties, delivered to a wideband lambda sensor, especially a gas mixture of an exhaust gas of an internal combustion engine of a motor vehicle, whereby the lambda sensor has a pumping cell with at least one gas measurement chamber, provision is made for the recognition of the gas composition of the gas mixture to result by means of modulation of the gas in the gas measurement chamber. Preferably the air number in the gas measurement chamber of the pumping cell is periodically altered, whereby the sensitivity of the lambda sensor to the gases, of which there are at least two, likewise periodically changes.

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: There is provided a control apparatus for a gas sensor, which has a sensor element equipped with first and second oxygen pumping cells. The sensor control apparatus is configured to drive the first oxygen pumping cell to adjust the oxygen concentration of gas under measurement, drive the second oxygen pumping cell to produce a flow of electric current according to the amount of oxygen pumped out of the oxygen concentration adjusted gas by the second oxygen pumping cell, perform specific drive control to control the amount of oxygen pumped by the second oxygen pumping cell to a predetermined level after startup of the sensor element and before the application of the drive voltage between the electrodes of the second oxygen pumping cell.

Abstract: A diagnostic kit disclosed herein comprises a nanoparticle-biomaterial complex, an extraction solution, a collection electrode, and a current peak measurement unit. The nanoparticle-biomaterial complex comprises: one or more nanoparticles selected from a metal group consisting of zinc, cadmium, lead, copper, gallium, arsenic, thallium, nickel, manganese and bismuth; one or more biomaterial-binding materials binding to the nanoparticles through a binding-stabilizing agent and binding specifically to the biomaterials to be detected; and a binding-stabilizing agent forming bonds between the nanoparticles and the biomaterial-binding materials. The extraction solution serves to isolate and extract the nanoparticles from the nanoparticle-biomaterial complex. The collection electrode serves to collect the nanoparticles from the extraction solution. The current peak measurement unit serves to measure current peaks corresponding to the nanoparticles collected from the collection electrode.

Abstract: Various methods, compounds and apparatus for the detection of analytes are provided. In one aspect, the direct oxidation of an alcohol is detected electrochemically. In another aspect, a reaction of an analyte is detected, wherein the reaction is catalysed by an enzyme and a cofactor, and wherein the cofactor comprises a moiety which is capable of acting as an electron mediator. In a further aspect, a chiral analyte is detected by resolving a enantiomeric mixture of the analyte and subsequently detecting at least one of the resolved enantiomers electrochemically. The invention is particularly relevant to the detection of alcohols, especially chiral alcohols.

Abstract: An electrochemical gas sensor is provided with a carbon-based measuring electrode (3) that it can be used for a large number of electrochemical detection reactions and can be manufactured at a low cost. The measuring electrode (3) contains carbon nanotubes.

Abstract: A method for monitoring a select analyte in a sample in an electrochemical system. The method includes applying to the electrochemical system a time-varying potential superimposed on a DC potential to generate a signal; and discerning from the signal a contribution from the select analyte by resolving an estimation equation based on a Faradaic signal component and a nonfaradaic signal component.

Abstract: A method for measuring the transmission rate of an analyte through a film. The method includes the steps of (i) separating a chamber into a first cell and a second cell with a known area of a film, (ii) flushing the first cell with an inert gas to remove any target analyte from the first cell, (iii) introducing a gas containing a known concentration of an analyte into the second cell, (iv) sealing the first cell to gas flow through the first cell, and (v) sensing any analyte in the first cell with a sensor that consumes the analyte at a rate greater than the rate at which the analyte is passing through the film, until a steady state rate of analyte consumption is measured by the sensor.

Abstract: The present invention is directed to a method of reducing the effects of interfering compounds in the measurement of analytes and more particularly to a method of reducing the effects of interfering compounds in a system wherein the test strip utilizes two or more working electrodes. In one embodiment of the present invention, a first potential is applied to a first working electrode and a second potential, having the same polarity but a greater magnitude than the first potential, is applied to a second working electrode.

Abstract: A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and/or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

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

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

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

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

Abstract: An oxygen sensor has a laminated body with a fluid sample inlet end and an electrical contact end, a fluid sample inlet, a substantially flat test chamber communicating with the fluid sample inlet where the test chamber is adapted to collect a fluid sample through the sample fluid inlet, a working electrode and a reference electrode within the test chamber, and a reagent matrix disposed on the working electrode where the reagent matrix contains an oxidase, a reduced form of a redox mediator and a peroxidase.

Abstract: A sensor comprises a substrate having nanoparticles of a conducting polymer such as polyanaline printed thereon. Also described is a printing composition for printing onto a substrate, the composition comprising nanoparticles of a conducting polymer such as polyanaline.

Abstract: Among other things, methods and systems are described for detecting chemicals including explosive materials. For example, a system for detecting materials includes a sample gathering unit designed to obtain a portion of a target material to be tested. In addition, the system includes a sample holding unit that has a first end designed to attach to the sample gathering unit and form a housing that retains at least the obtained portion of the target material. Further, a reagent holding unit is included and designed to attach to a second end of the sample holding unit. The reagent holding unit is designed to introduce the reagent into the formed housing to mix with the obtained target material and start a chemical reaction.

Abstract: Methods for calculating an analyte concentration of a sample are provided. In one exemplary embodiment the method includes steps that are directed toward accounting for inaccuracies that occur as a result of temperature variations in a sample, a meter, or the surrounding environment. In another exemplary embodiment the method includes steps that are directed toward determining whether an adequate sample is provided in a meter because insufficient samples can result in inaccuracies. The methods that are provided can be incorporated into a variety of mechanisms, but they are primarily directed toward glucose meters for blood samples and toward meters for controls solutions.

Abstract: According to the present invention, phenols may be detected using an electrochemical sensor comprising a final compound, a working electrode and an electrolyte in contact with the working electrode, wherein the first compound operatively undergoes a redox reaction at the working electrodes to form a second compound which operatively reacts in situ with the phenol, wherein said redox reaction has a detectable redox couple and wherein the sensor is adapted to determine the electrochemical response of the working electrode to the consumption of said second compound on reaction with the phenol. The phenol may be, for example, cannabinoid or a catechin compound.

Abstract: The present invention is an electrochemical cell system gas sensor that detects a subject substance to be detected using an electrochemical reaction system and comprises an ion conduction phase and at least two kinds of electrode facing each other and contacting the ion conduction phase, an electrode structure thereof comprising a chemical detection electrode layer having a selective adsorption characteristic relative to the subject substance to be detected and at least one reference electrode layer serving as a counter electrode to the chemical detection electrode layer, a manufacturing method thereof, and a method of detecting the subject substance to be detected, the present invention provides a chemical detection system having an extremely high response speed and great detection ability irrespective of high or low temperatures and even in the presence of excessive oxygen that impairs the chemical reaction of the subject substance to be detected.

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

Abstract: A biosensor comprising a conducting polymer and a facilitating agent that combine to form a polymeric matrix that interacts with electrophilic compounds, wherein an electrochemical property of the polymer is altered in the presence of an electrophilic compound.

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

Abstract: 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: An electrode plate for electrochemical measurements capable of measuring the concentration of a target substance included in a sample solution with favorable accuracy and high sensitivity is provided The electrode plate for electrochemical measurements 1 of the present invention includes a substrate 31, an upper layer 40 provided on the superior face of the substrate, a lower layer 11 provided on the inferior face of the substrate, a first electrode body 32 sandwiched between the superior face of the substrate and the upper layer, and a second electrode body 12 sandwiched between the inferior face of the substrate and the lower layer, wherein: the upper layer has a plurality of upper layer through-holes 41; the first electrode body has a plurality of first electrodes 32d including a portion exposed from the superior face of the upper layer via the upper layer through-hole in the first electrode body; the substrate has a plurality of substrate through-holes 33; and the second electrode body has a plurality of

Abstract: Methods of determining a corrected analyte concentration in view of some error source are provided herein. The methods can be utilized for the determination of various analytes and/or various sources of error. In one example, the method can be configured to determine a corrected glucose concentration in view of an extreme level of hematocrit found within the sample. In other embodiments, methods are provided for identifying various system errors and/or defects. For example, such errors can include partial-fill or double-fill situations, high track resistance, and/or sample leakage. Systems are also provided for determining a corrected analyte concentration and/or detecting some system error.

Abstract: A gas sensor is constructed as follows. A protector (4) covering around a gas sensing element (2) has an inner hollow-cylindrical portion (6) and an outer hollow-cylindrical portion (7) that is provided coaxially with the inner hollow-cylindrical portion (6) with an air space (8) in between. Outer-wall gas inlet openings (13) are formed in the outer hollow-cylindrical portion (7), and guiding bodies (10) extending inward are attached to the outer-wall gas inlet openings (13). Inner-wall gas inlet openings (11) are formed in the inner hollow-cylindrical portion (6) at positions nearer to the gas sensing element (2) than the outer-wall gas inlet openings (13). A side wall (9) face of the inner hollow-cylindrical portion (6) opposite the outer-wall gas inlet openings (13) is formed so as to be parallel to a side wall (12) of the outer-hollow cylindrical portion (7) or so as to have a slop-like shape with a diameter enlarging in the axial direction toward a bottom wall (17) of the protector (4).

Abstract: An electrochemical sensor system for sensing free radicals or materials which generate free radicals in solution includes a working electrode coated with a plurality of cerium oxide nanoparticles and a counter electrode. A solution to be analyzed provides electrolytes to electrically couple the working electrode to the counter electrode. Electronics are connected to at least one of the working and counter electrodes for measuring and amplifying an electrical current signal generated by reduction or oxidation occurring at the working electrode, wherein in a presence of free radicals an electrical current signal flows between the working electrode and the counter electrode. The system can be used to sense the presence of hydrogen peroxide.

Abstract: A method and biosensor device for detecting single strand target nucleic acid by cyclic voltammetry is described. A porous silicon chip is linked to bound DNA probe complementary to the target nucleic acid. The device is particularly useful for detecting microorganisms and viruses that may be pathogenic or cancer genes, however any target nucleic acid can be detected by using a specific DNA probe.

Abstract: The present invention relates to electrochemical cells including a first working electrode 32, a first counter electrode 34, a second working electrode 36, and a second counter electrode 38, wherein the electrodes are spaced such that reaction products from the first counter electrode 34 arrive at the first working electrode 32, and reaction products from the first and second counter electrodes 34, 38 do not reach the second working electrode 36. Also provided is a method of using such electrochemical cells for determining the concentration of a reduced or oxidized form of a redox species with greater accuracy than can be obtained using an electrochemical cell having a single working and counter electrode.

Abstract: The present invention relates to systems and methods using colorimetric indicators of oxidation in consumer products. In particular, betalains are used as oxidation indicators in food, pharmaceutical, and other products.

Abstract: The present invention relates to a method of altering the sensitivity and/or selectivity of a chemiresistor sensor, to a sensor and a sensor array produced by such method.

Abstract: Novel transition metal complexes of iron, cobalt, ruthenium, osmium, and vanadium are described. The transition metal complexes can be used as redox mediators in enzyme-based electrochemical sensors. The transition metal complexes include substituted or unsubstituted (pyridyl)imidazole ligands. Transition metal complexes attached to polymeric backbones are also described.

Abstract: A method of adjusting the output of an electrochemical sensor includes the steps of: simulating the presence of an analyte gas electronically; measuring a response of the sensor to the electronic simulation; and adjusting the output of the sensor as a function of the measured response to the electronic simulation. The method of adjusting the output of an electrochemical sensor having a working electrode and a counter electrode preferably includes the steps of: electronically causing a current flow between the working electrode and the counter electrode; measuring a response of the sensor to the current demand; and using the measured response to adjust the sensor output during sampling of an analyte gas.

Abstract: The present invention relates to systems, methods, and devices for determining the concentration of an analyte in a sample. The use of linear, cyclic, or acyclic voltammetric scans and/or semi-integral, derivative, or semi-derivative data treatment may provide for increased accuracy when determining the concentration of an analyte in a sample. Hematocrit compensation in combination with the data treatments may reduce the hematocrit effect with regard to a glucose analysis in whole blood. In another aspect, fast scan rates may reduce the hematocrit effect.

Abstract: A method and apparatus for provide a stable voltage to an electrochemical cell used for measurement of an analyte such as glucose in a liquid sample. The apparatus uses a circuit in which multiple switching positions provide both calibration information for use in calibration of electronic components in the circuit and error checking functionality.

Abstract: A method for estimating the concentration of a particular gas in a gas mixture having a fluctuating pressure is provided. A sensor output signal indicating the concentration of a particular gas in the gas mixture is received from a gas sensor. The received sensor output signal may vary over time due to the fluctuating pressure of the gas mixture. The received sensor output signal may be processed to determine an estimate of the concentration of the particular gas in the gas mixture. The processing may include performing an autocorrelation of the signal. In some embodiments, the particular gas is oxygen and the method is used to estimate the concentration of oxygen in a gas mixture having a fluctuating pressure.

Abstract: An electric sensor array which is provided with several sensor positions that each have at least two microelectrodes. Molecular substances can be detected electrochemically and charged molecules can be transported or handled using the array. Measuring procedures can be effected, especially using two addressing procedures, in which sensor positions can be individually addressed and electrochemically or electrically controlled by pairing or in groups for voltage or impedance measurements. For biomolecular assays, affinity-binding molecules can be immobilized at the sensor positions, between the microelectrodes, or on auxiliary surfaces.

Abstract: The invention is a redox control and monitoring platform that is to be used in conduction with another detection scheme. The platform includes a portion of an electrochemical control. The electrochemical control can be operated to control and measure the redox environment of a sample. The electrochemical control can be provided in a multiplicity of test regions to allow high throughput analysis of a multiplicity of samples. The present method and system allows the determination of the effect of the change in redox environment on the binding or other activity of the species in the sample that is directly affected by the redox environment.

Abstract: A process and a device are provided for monitoring the hydrogen concentration in a gas with at least one device, which comprises an electrochemical gas sensor and a bipotentiostat, e.g., for use in internal combustion engines with hydrogen, in fuel cells and in the petrochemical industry. The electrochemical gas sensor used has two working electrodes (3) and (4), with which the hydrogen and oxygen concentrations are determined in the gas in different steps due to the application of a voltage by a bipotentiostat (5-18). In an additional, optional step, a voltage in the range of ?1,100 mV to ?800 mV is applied to a working electrode (4), so that hydrogen is formed at the working electrode (4) and the functional surface of the working electrode (4) as well as the sensitivity of the working electrode (3) to hydrogen can be checked.

Abstract: An electrode comprises a catalyst and material to help stabilize an oxide of the catalyst. The electrode for one embodiment may be used for an electrochemical sensor or sensor cell.

Abstract: Electrochemical monitoring system and method are provided for online determination of hydrogen peroxide concentration in slurries, e.g., a chemical mechanical polishing slurry. The monitoring system includes an electrochemical cell fluidly coupled to receive a slurry including hydrogen peroxide. The cell includes at least a working electrode made up of tungsten, a reference electrode and a counter electrode. The system further includes a potentiostat electrically coupled to the working electrode to supply a desired potentials in increments to the working electrode and measure current flow between the working electrode and the counter electrode. The amount of passive current established between the working electrode and the counter electrode over a selected time window is indicative of the concentration of hydrogen peroxide in the slurry.

Abstract: A method and apparatus for detecting the presence of carbon monoxide in a gas which may also contain contaminating substances uses a pre-treatment means to absorb contaminating substances and to convert them to non-contaminating substances.

Abstract: An electroactive material (e.g., a doped electroactive polymer, or an intercalcated carbon/graphite fiber) responsive to the concentration of a chemical component is used to sense the concentration of the chemical component inside a chamber. The conductivity, or other electrical property of the electroactive material, varies in response to the exposure to the chemical component.

Abstract: An electrode comprises a catalyst and material to help stabilize an oxide of the catalyst. The electrode for one embodiment may be used for an electrochemical sensor or sensor cell.

Abstract: The inventive electrochemical sensor for determining the concentration of an oxidising gas in the studied gas or liquid comprises a body containing an electrolyte and measuring and counter electrodes contacting said electrolyte. The counter electrode contains carbon material and has a potential equal to or higher than 750 mV when it is measured in relation to a hydrogen reference electrode in the same electrolyte. The inventive method for producing said electrochemical sensor and determining the oxidising gas in the studied gas is also disclosed.