Abstract: A sensor includes a working electrode in contact with an analyte solution; an amplifier including: a source terminal; a drain terminal; a back gate terminal; and nanowires, each nanowire electrically connecting the source terminal to the drain terminal; and an insulator having a first side and a second side. The working electrode is positioned to the first side of the insulator. The source terminal, the drain terminal, and the nanowires are positioned to the second side of the insulator. The insulator prevents direct electrical contact between the working electrode, the analyte solution and either the source terminal, the drain terminal, or the nanowires. The working electrode is configured such that, when a chemical species is present in the analyte solution, a variation in an electrical field at a location of the nanowires is induced, inducing a corresponding variation in an electrical current between the source terminal and the drain terminal.

Abstract: The present disclosure is directed to systems, methods and tools that measure ionic concentrations and downhole enthalpy of a flowing geothermal fluid in real-time at high-temperature and pressure. The systems, methods and tools include measuring the concentration of selected naturally occurring ions found in the liquid phase of the geothermal fluid throughout the wellbore using novel electrochemical sensor technologies. The change in liquid-phase ion concentration will be used to calculate the proportion of liquid to steam and allow for accurate enthalpy measurements. The techniques and technologies described here can be applied to any application of electrochemical sensing in extreme environments.

Abstract: The present disclosure relates to a potentiometric probe for measuring a measured variable that represents an ion concentration in a measuring medium, including a probe base including a sensor circuit, and two electrochemical half-cells arranged such that one of the half-cells surrounds at least one portion of the other half-cell, wherein at least one of the half-cells is configured as a module which is connected to the probe base via a mechanical and electrical interface. In another embodiment, one of the half-cells is a measuring half-cell including an ion-selective membrane and a terminal lead which electrically contacts the ion-selective membrane. The other half-cell is a reference half-cell, wherein the measuring half-cell and/or the reference half-cell are each configured as a module which is connected to the probe base via a mechanical and electrical interface.

Abstract: Improved sensor assemblies are provided. More particularly, the present disclosure provides improved and highly advantageous metal oxide based sensor assemblies configured to sense low concentration of specific gases, and related methods of use. The present disclosure provides improved physical forms of metal oxide films (e.g., WOx films, CeOx films). The exemplary metal oxide films can be fabricated by a Reactive Spray Deposition Technology (RSDT). The highly advantageous films/materials can be utilized in sensor assemblies to detect simple chemical components of the breath that correlate with human health conditions (e.g., the presence of acetone in diabetic patients). These films/materials demonstrate improved thermal stability under the sensor's operating conditions, as well as improved sensitivity to low concentration of the analyte, selectivity and quick responsiveness.

Abstract: An optoelectronic device for detecting volatile organic compounds is described, including a die with a semiconductor body, the die forming a MOSFET transistor and at least one photodiode. The optoelectronic device is optically couplable to an optical source that emits radiation with a spectrum at least partially overlapping the absorption spectrum range of the semiconductor body. The MOSFET transistor is planar and includes a gate region and a catalytic region that is arranged on the gate region such that, in the presence of a gas mixture including volatile organic compounds, the MOSFET transistor can be biased to generate an electrical signal indicating the overall concentration of the gas mixture. The photodiode generates a photocurrent that is a function of the concentration of one or more polycyclic aromatic hydrocarbons present in the gas mixture.

Abstract: Embodiments are directed to a chemical sensor and a method of fabricating a chemical sensor that includes a membrane having full circumferential adhesion. The chemical sensor device includes a silicon substrate comprising a sensor-side and a backside. The sensor-side includes a sensor-side electrode; a first passivation layer disposed on the substrate; and a second passivation layer on the first passivation layer and adjacent to the sensor-side electrode, the passivation layer comprising an adhesion trench exposing a portion of the first passivation layer, and a polyimide ring disposed on the second passivation layer. The backside includes a backside electrode on the backside of the substrate. The substrate includes an electrically isolated doped region, such as a through silicon via, electrically connecting the sensor-side electrode and the backside electrode.

Abstract: A method for determining orthophosphate content of a liquid, comprising: registering a first measurement signal (ISE1) of an ion selective dihydrogen phosphate sensor; registering a second measurement signal (ISE2) of an ion selective hydrogen phosphate sensor; and determining the orthophosphate content of the liquid based on the first (ISE1) and second (ISE2) measurement signals. The dihydrogen phosphate sensor can comprise an ion selective dihydrogen phosphate electrode and the hydrogen phosphate sensor an ion selective hydrogen phosphate electrode. In the step of determining the orthophosphate content of the liquid, a cross-sensitivity of the dihydrogen phosphate electrode to hydrogen phosphate present in the liquid and a cross-sensitivity of the hydrogen phosphate electrode to dihydrogen phosphate present in the liquid can be taken into consideration.

Abstract: The present invention announces a method for extending the storage life of a test reagent for quantification of ionic components in samples by using an anion sensor. The purpose of the present invention is to provide an anion sensor, wherein the storage life of the anion sensor itself may be extended, to thereby extend the storage life of the anion sensor beyond that of conventional anion sensors. According to the present invention, through adjustment of the pH of the internal solution (internal gel liquid), it is possible to provide an anion sensor that maintains consistent performance, and has longer storage life.

Abstract: The ability to switch at will between amperometric measurements and potentiometric measurements provides great flexibility in performing analyzes of unknowns. Apparatus and methods can provide such switching to collect data from an electrochemical cell. The cell may contain a reagent disposed to measure glucose in human blood.

Abstract: The present invention is directed to an electrochemical sensor involving an electrode and a coating that surrounds the electrode, the coating comprising a structural component, a water immiscible solvent, a resistance decreasing component, and an ion exchange component, wherein the coating selectively partitions an electrochemically active drug from a fluid or vapor sample whereby an electrochemical signal within the coating can be measured using the electrode. Devices and methods for using this electrochemical sensor are also disclosed.

Abstract: An apparatus for the real-time, in-situ monitoring of actinide-ion concentrations. A working electrolyte is positioned within the interior of a container. The working electrolyte is separated from a reference electrolyte by a separator. A working electrode is at least partially in contact with the working electrolyte. A reference electrode is at least partially in contact with the reference electrolyte. A voltmeter is electrically connected to the working electrode and the reference electrode. The working electrolyte comprises an actinide-ion of interest. The separator is ionically conductive to the actinide-ion of interest. The separator comprises an actinide, Zr, and Nb. Preferably, the actinide of the separator is Am or Np, more preferably Pu. In one embodiment, the actinide of the separator is the actinide of interest. In another embodiment, the separator further comprises P and O.

Abstract: A sensor device for detecting and/or measuring gases includes two electrodes. A thin-layered proton-conductive material is fitted between the two electrodes. The gas can be detected and/or measured by a proton gradient that arises due to different gas concentrations.

Abstract: An apparatus for real-time, in-situ monitoring of actinide ion concentrations which comprises a working electrode, a reference electrode, a container, a working electrolyte, a separator, a reference electrolyte, and a voltmeter. The container holds the working electrolyte. The voltmeter is electrically connected to the working electrode and the reference electrode and measures the voltage between those electrodes. The working electrode contacts the working electrolyte. The working electrolyte comprises an actinide ion of interest. The reference electrode contacts the reference electrolyte. The reference electrolyte is separated from the working electrolyte by the separator. The separator contacts both the working electrolyte and the reference electrolyte. The separator is ionically conductive to the actinide ion of interest. The reference electrolyte comprises a known concentration of the actinide ion of interest. The separator comprises a beta double prime alumina exchanged with the actinide ion of interest.

Abstract: The disclosure provides monolithic electrodes including a substrate defining a walled cavity having a floor, an electrically conductive cathode layer overlaying the cavity floor, an electrically conductive contact pad overlaying the substrate, an electrically conductive via in electrical communication with the cathode layer and the contact pad, and a porous membrane layer overlaying the cavity and defining a chamber formed by the porous membrane layer, the walled cavity, and the cavity floor. The disclosure also provides pH transducers including monolithic indicator and reference electrodes, and methods of making and using monolithic pH electrodes and transducers.

Abstract: Temperature compensation for ion-selective electrodes is obtained by positioning a temperature-measuring element in a chamber of limited thermal mass which is in thermal contact with the measuring electrode filling solution but is thermally isolated from other filling solutions in the electrode. In a preferred embodiment, the temperature-measuring element comprises a thermistor enclosed within thin flexible tubing; the electrical leads of the thermistor are forced against a segment of the inner wall of the tubing by an elongated strand of material abutting the thermistor to enhance heat transfer with the thermistor.

Abstract: A wellbore tool has an electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid downhole in a wellbore. The sensor comprises a temperature- and pressure-resistant housing containing a flow path for the fluids. The fluids flow over one side of a gas permeable membrane the other side of the membrane being exposed to a chamber containing at least two electrodes and containing a reaction solution which together with the hydrogen sulphide or thiols create a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid. Measurement is made by passing formation fluid along the flow path and repeatedly applying varying potential to one electrode and measuring the peak current flowing between that electrode and a second electrode.

Abstract: A system and method for online monitoring of molten salt corrosion of a component of an apparatus is disclosed. First and second electrodes are electrically isolated from each other within the component and exposed to a corrosive operating environment of the apparatus. The first and second electrodes are electrically coupled such that when an electrical potential difference exists between the first and second electrodes an electrical current flows between the first electrode and the second electrode. The electrical potential difference between the first electrode and the second electrode is based at least in part on molten salt corrosion at the first electrode or the second electrode. At least one of the electrical potential difference or the electrical current flowing between the first electrode and second electrode is measured and analyzed such that a corrosion characteristic of the component can be predicted.

Abstract: A reference electrode traps silver ions and chloro complex ions leaching to an internal filling solution so that the blocking of the liquid junction can be prevented. A silver/silver chloride electrode can be provided as an internal electrode in an internal filling solution; and a tube which houses, in order from top to bottom, the internal electrode, an inorganic cation exchanger for trapping silver ions and/or chloro complex ions from leaching from the internal electrode, and a ceramic member for preventing the diffusion of the silver ions and/or the chloro complex ions to the internal filling solution.

Abstract: A wastewater analysis sensor cartridge (10) according to the invention is intended to be used only once. It has a liquid-tight housing (20), which contains at least one electrochemical sensor element (30, 32) and at least one reference element (56). Furthermore, the housing (20) contains a sensor element electrolyte tank (40,42) and a reference element electrolyte tank (44). The ion-sensitive membranes (31, 33) of the sensor elements (30, 32) and the housing (20) consist of plastic.

Abstract: A NOx-decomposing electrode is provided having a certain or a high NOx-decomposing/reducing ability, which is formed on a third solid electrolyte layer for decomposing a NOx to produce oxygen. The detecting electrode contains a noble metal Pt, a material ZrO2 of the third solid electrolyte layer, and a mixture containing silica (SiO2) and alumina (Al2O3). Specifically, the detecting electrode contains 80% to 90% by weight of the Pt, 9.5% to 19.8% by weight of the ZrO2, and 0.2% to 0.5% by weight of the mixture containing silica and alumina.

Abstract: Provided are fabrication, characterization and application of a nanodisk electrode, a nanopore electrode and a nanopore membrane. These three nanostructures share common fabrication steps. In one embodiment, the fabrication of a disk electrode involves sealing a sharpened internal signal transduction element (“ISTE”) into a substrate, followed by polishing of the substrate until a nanometer-sized disk of the ISTE is exposed. The fabrication of a nanopore electrode is accomplished by etching the nanodisk electrode to create a pore in the substrate, with the remaining ISTE comprising the pore base. Complete removal of the ISTE yields a nanopore membrane, in which a conical shaped pore is embedded in a thin membrane of the substrate.

Abstract: An electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid in a wellbore comprises a temperature- and pressure-resistant housing containing a flow path for the fluids. The fluids flow over one side of a gas permeable membrane made of zeolite or a suitable ceramic material, the other side of the membrane being exposed to a chamber containing a reaction solution which together with the hydrogen sulphide or thiols create a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid.

Abstract: The present invention relates to a multi-functional sensor system that simultaneously measures cathode and anode electrode potentials, dissolved ion (i.e. oxide) concentration, and temperatures in an electrochemical cell. One embodiment of the invented system generally comprises: a reference(saturated) electrode, a reference(sensing) electrode, and a data acquisition system. Thermocouples are built into the two reference electrodes to provide important temperature information.

Abstract: The present claimed invention is to provide a reference electrode wherein variations of a potential difference at a liquid junction can be removed almost completely, contamination of a sample solution can be minimized, a frequency to supply and replace an internal solution is lessened, the liquid junction is prevented from being clogged, high durability for a long term can be maintained and a measurement with high accuracy can be conducted, and comprises an internal electrode 21, an internal solution 22 that makes a contact with the internal electrode 21 and a liquid junction 23 that continues into the internal solution 22, wherein the liquid junction 23 is made by the use of a gelled hydrophobic ionic liquid.

Abstract: An electrochemical gas sensor with a stacked arrangement of electrodes and nonwoven layers arranged in parallel, comprising at least one measuring electrode (3) and at least one counterelectrode (5). A porous membrane (8) that is permeable to air is in contact with the stacked arrangement of electrodes and nonwoven layers arranged in parallel at least on one side, at least one layer of a hydrophilic nonwoven (7) is located between the electrodes. The porous membrane (8) that is permeable to air and the hydrophilic nonwoven (7) extend into a separate equalization volume (9), which is filled with electrolyte at least partially and is located at least partially in one plane with the electrodes. The separate equalization volume (9) surrounds the electrode arrangement at least partially in this plane, and the porous membrane (8) that is permeable to air is exposed to ambient pressure at least in partial areas.

Abstract: The present claimed invention intends to provide a responsive glass membrane for ion selective electrode glass and an ion selective electrode comprising the responsive glass membrane that produces a self-cleaning function when the ultraviolet rays are irradiated although no change is brought in a composition of a sample solution as being an object to be measured and that is low in electric resistance value and superior in responsivity under an ordinary measurement environment. The responsive glass membrane for ion selective electrode is made of the titanium-containing oxide glass that contains 20˜80 mol % of titanium dioxide and lithium oxide.

Abstract: A reference electrode traps silver ions and chloro complex ions leaching to an internal filling solution so that the blocking of the liquid junction can be prevented. A silver/silver chloride electrode can be provided as an internal electrode in an internal filling solution; and a tube which houses, in order from top to bottom, the internal electrode, an inorganic cation exchanger for trapping silver ions and/or chloro complex ions from leaching from the internal electrode, and a ceramic member for preventing the diffusion of the silver ions and/or the chloro complex ions to the internal filling solution.

Abstract: An ion sensor has a flow path through which a sample flows. An ion-exchange membrane is in contact with the sample in the sample flow path. An internal solution is provided on one side of the ion-exchange membrane. An internal electrode is provided so as to come in contact with the internal solution. The surface of the ion-exchange membrane that does not come in contact with the sample is coated with a two-liquid-mixed epoxy resin.

Abstract: Methods for fabricating ion sensitive field effect transistors (ISFETs) with SnO2 extended gates. A SnO2 detection film is formed on a substrate by sol-gel technology to serve as an extended gate. The SnO2 detection film is electrically connected to a conductive wire, and an insulating layer is formed on the surface of the ISFET but part of the SnO2 detection film and the conductive wire are left exposed. The exposed conductive wire is electrically connected to a gate terminal of a MOS transistor.

Abstract: A fluoride-sensitive electrode having a tubular electrode shaft, a lanthanum fluoride crystal, which closes the end of the electrode shaft, an internal electrolyte sealed between the lanthanum fluoride crystal and a closure in the electrode shaft, and a contact wire which dips into the internal electrolyte, wherein the internal electrolyte has a pH of ?9.0 and a fluoride concentration of ?0.1 M. The invention also includes the method of using the electrode to determine fluoride ion concentration.

Abstract: Methods and insulator electrode devices for performing electrochemical reactions are disclosed. The devices consist of high specific surface area electrodes based on a channeled conducting base material that has been coated with an organic or inorganic insulating film or multiple layers of such films. The chemical reactions are exemplified by exciting one or several label compounds into an excited state which is spontaneously de-excited by emission of ultraviolet, visible or infrared light, in aqueous solution. This provides the basis for reproducible analytical applications in bioaffinity assays such as immunoassays and DNA-probing assays.

Abstract: The present invention provides a class of sensors prepared from at least a first material having a positive temperature coefficient of resistance and a second non-conductive or insulating material compositionally different than the first material that show an increase sensitivity detection limit for polar and non-polar analytes. The sensors have applications in the detection of analytes in the environment, associated with diseases and microorganisms.

Abstract: The invention concerns an electrode device comprising an ion selective material, a solid state, inner reference system of sodium vanadium bronze and a contact material, where sodium may be reversibly intercalated, in the bronze. Such an electrode device may for instance be sensitive to ions, such as H+, Na+, K+and Ca2+. It may also include a reactive material in which a particular analyte is reacted to form an ion product, to which the ion selective material is sensitive, such as in electrode devices of the Severinghaus-type or in biosensors. The electrode device according to the invention can be prepared by thick film printing.

Abstract: In this invention, a potentiometric electrochemical sensor and biosensor based on an uninsulated solid-state material was presented.

Abstract: Disclosed is a microchip-based differential-type potentiometric oxygen gas sensor, which comprises a working electrode and a reference electrode. The working electrode is composed of a cobalt-plated electrode, a buffered hydrogel, and an ion sensitive gas permeable membrane while the reference electrode is composed of an oxygen non-sensitive silver chloride electrode and the same ion-selective gas-permeable membrane of working electrode. By taking advantage of the corrosion potential, the microchip-based oxygen gas sensor can accurately and quickly detect the content of dissolved oxygen in a sample solution. With this structure, the oxygen gas sensor is applied to a microchip-based all potentiometric multi-sensor capable of detecting two or more ions and gas species on a single chip.

Abstract: The invention provides a novel solution isoelectric focusing device and method that can reproducibly fractionate charged molecules into well-defined pools. This approach can be applied to mixtures of charged molecules, such as eukaryotic proteome samples where reproducible resolution and quantitation of greater than 10,000 protein components is feasible.

Abstract: A reference junction for a reference half-cell, the reference junction including an ion-barrier membrane and being sized and shaped for removable receipt within a receptacle of a reference half-cell housing. The reference junction may be included in an electrochemical potential measurement sensor for use in making pH, other selective ion activity, oxidation-reduction potential, and other electrochemical potential measurements.

Abstract: A reference electrode (1) for electrochemical measurements includes a metallic palladium-containing electrode component (3) which is covered by a layer (4) formed of or containing a palladium compound poorly soluble in aqueous media. Positioned on layer (4) is a reference electrolyte (5) which contains anions of this palladium compound in dissolved form (FIG. 4).

Abstract: An object of the present invention is to provide an electrode and a field effect transistor having excellent ion selectivity using a noncyclic peptide. In order to achieve the above object, the ion sensor of the present invention using a noncyclic peptide is an ion sensor where a noncyclic peptide is contained in a sensing membrane. The said noncyclic peptide may contain at least two kinds of natural amino acids or non-natural amino acids. The ion sensor of the present invention may be constituted by an ion-selective electrode or by an ion-selective field effect transistor. Examples of the main responding ion are magnesium ion, lead ion, potassium ion, calcium ion, nickel ion, copper ion, zinc ion and cadmium ion.

Abstract: A phosphate ion selective electrode, with which the detection limit is made small to enable measurement of phosphate ion concentrations of down to low concentration, and a method of manufacturing the abovementioned phosphate ion selective electrode, wherein a sensing membrane 1 of an ion selective electrode A is comprised of a solid membrane having a slightly soluble metal salt as the main component thereof.

Abstract: The invention relates to a sensor for measuring ion concentration or gas concentration, with a gas- or ion-sensitive layer (6) that has two sensitive partial areas (20 and 21), two conducting areas (1b and 2b), each coupled capacitively through air gaps (9and 10) with one of the sensitive partial areas (20 and 21), with the capacitances of the couplings being different, and a comparison circuit (1a, 2a, 3, 4, 5) which has at least one first transistor (T1) connected with the first conductive area and a second transistor (T2) connected with the second conductive area, and at least one output at which a signal can be tapped that depends on the potential of sensitive layer (6).

Abstract: An improved combination ion-selective electrode apparatus is provided that comprises an electrode body, a reference electrode, and an ion-sensing electrode. The reference electrode comprises a ion-permeable junction. A removable membrane cap contains a ion-selective membrane. The membrane cap can be removed from the ion-selective electrode apparatus without endangering the integrity of the reference electrode and is distinct from the ion-permeable junction. The membrane cap contains a removable ion-sensitive membrane that can be replaced if the ion-sensitive membrane fails to thereby place the combination ion-selective electrode apparatus back into service. Moreover, a single combination ion-selective electrode apparatus can be used to measure a variety of analyte ions by simple replacement of the membrane cartridge.

Abstract: A phosphate ion selective electrode, with which the detection limit is made small to enable measurement of phosphate ion concentrations of down to low concentration, and a method of manufacturing the abovementioned phosphate ion selective electrode, wherein a sensing membrane 1 of an ion selective electrode A is comprised of a solid membrane having a slightly soluble metal salt as the main component thereof.

Abstract: The invention concerns a sampling system and a process for its production. Such systems can easily be employed throughout in chemical and biochemical analysis. The sampling system should be simply constructed and universally usable alone and in combination and fabricable with little effort. The sampling system constructed as per the invention for analytes which are fluid or are contained in fluids consists of a planar support with various holes in it through which the particular fluid can pass into a channel which it subsequently exits. The channel is at least partly covered by a cover over the side opposite the support. In addition, a membrane pervious to the analyte is inserted which at least partly covers the channel on its open upper side. The areas not covered by the cover can be used to extract the analyte or to make direct measurements.

Abstract: The present invention discloses a method of forming a metal layer by thermal evaporation or RF reactive sputtering in order to fabricate a light shielding layer for an ion sensitive field effect transistor. The multi-layered construction of the ion sensitive field effect transistor with a metal thin film as a light shielding layer is SnO2/metal/SiO2 or SnO2/metal/Si3N4/SiO2, and is able to lower the effect of light successfully.

Abstract: A micro-circuit for performing analyses of multimolecular interactions and for performing molecular syntheses, comprising: (a) a support; (b) at least one micro-electrode attached to the support, the micro-electrode being selectively electronically activated and the micro-electrode having a protective layer which is removable; (c) a binding entity for attachment to the at least one micro-electrode, the binding entity being capable of attachment to at least one micro-electrode when the protective layer has been removed; and (d) a power source being operatively connected to at least one micro-electrode for electronically activating at least one micro-electrode. The micro-circuit of the present invention also includes embodiments featuring a micro-circuit reader for detecting the interaction of the binding entity to a complementary probe, as well as methods for making and using the micro-circuit of the present invention.

Abstract: A pH sensitive microsensor which comprises a substrate on which a sensor membrane is formed by laser ablation of a target and depositing the target material on the substrate.

Abstract: A filter has a first filter layer made of TiO.sub.2 of Ti.sub.4 O.sub.7 particles deposited on a second filter layer by stainless steel particles. The first layer has a smaller pore size than the second layer. The construction of the filter, the relative thicknesses of the layers and the resistances thereof to movement therethrough of electrolytically generated gas located between the two layers when the filter is permeated with liquid are such that the gas reaches the upstream side of the filter before the downstream side. In one embodiment stainless steel particles are sintered and rolled with a textured roller before ceramic particles are applied and rolled. An intermediate layer of metal particle peaks and ceramic filled troughs is thus provided which has high tortuosity. The resistance to flow at the metal/ceramic interface can be increased by electrodeposition of metal there.

Abstract: Described is a combination, PVC-membrane, Ion-Selective Electrode (ISE) with a replaceable sensing module and a single-junction, sleeve-type reference electrode. pH and ion-selective electrodes (ISEs) in the "Combination" configuration, i.e., single probes containing both the sensing and reference half-cells, are more convenient, more economical, and can be used to analyze smaller samples than an equivalent pair of separate half-cell electrodes.

Abstract: A composite electrode, comprising:a solid non-metallic substrate, (such as ceramic, glass, or epoxy resin,)and, bonded directly or indirectly to said substrate,a non-conducting matrix, incorporating particles which are accessible to the electrode surface and contain an insoluble metal salt (e.g. halide) in direct electrical contact with the metal corresponding to said salt, said metal being present either (i) in the form of metallic particles incorporated in a non-conducting matrix zone disposed so that said metal salt-containing particles are located between said metallic particles and said electrode surface, and/or (ii) a solid metallic surface in the form of an intermediate layer between said matrix and said substrate.