Abstract: An ion-selective electrode for determining an electrolyte concentration in an aqueous solution includes an ion-selective layer and a potential-sensitive fluorescent indicator in the ion-selective layer, the fluorescence intensity of the potential-sensitive fluorescent indicator being measured to provide an indication of the electrolyte concentration.

Abstract: An ion-selective electrode having an electrically insulating substrate with a substantially planar first surface, and having a non-metallic conductor for sensing a potential affixed to the first surface beneath an ion-sensitive membrane. An electrically insulating layer covers at least a portion of the non-metallic conductor and means for making electrical contact with the non-metallic conductor.

Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence or measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.

Abstract: A membrane for an enzyme-electrode type sensor treated to increase the range of linearity of the sensor response.

Abstract: A porous composite membrane comprises a base membrane of high mechanical strength and a coating of a hydrophilic polymer on the surface of the membrane and on the walls of the pores. The invention includes a method to prepare the membrane and a biosensor including the membrane.

Abstract: The invention relates to a process for manufacturing a REFET and/or CHEMFET, comprising: (a) covalent bonding of a hydrophilic polymer layer to an isolator layer applied to a semiconductor material; (b) the absorption of water or a watery solution into said hydrophilic polymer layer; and (c) the binding of a hydrophobic polymer layer to the water holding hydrophilic polymer layer. It is advantageous that this water holding hydrophilic polymer layer also contains an electrolyte and/or a buffer.Preferably an ion to be measured with the CHEMFET also forms part of the electrolyte.

Abstract: A description is given of sensors in in the form of field effect transistors and capacitors which are suitable for qualitatively and quantitatively determining species to be analyzed, for example molecules or ions, in liquid or gaseous media. A special field of application is the selective determination of the presence and concentration of gases. The sensors are defined in that they have a sensitive layer consisting of a heteropolysiloxane.

Abstract: Electrochemical microsensors formed of a substrate containing means for sensing potential or current, including active and passive electronic devices and electronic circuits, and a micromachined structure containing at least one cavity overlying the sensing means, wherein the structure and substrate are bonded together at a temperature less than about 400.degree. C., in the absence of high voltage fields, using means not requiring highly planarized surfaces. A wide variety of materials can be utilized for both the substrate and overlying structure.Diverse embodiments are possible, having in common a cavity containing a chemically sensitive material and means for sensing potential or current.The resulting structural organization of materials transduces a chemical signal, such as concentration, to an electrical signal, which is then "processed" by the underlying FET or metallic connections.

Abstract: An ion sensor includes an electrically conductive substrate, a redox layer coating the surface of the electrically conductive substrate, a barrier layer coating the surface of the redox layer, and an ion-selective layer coating the surface of the barrier layer. The barrier layer functions to prevent migration between the ion-selective layer and redox layer of substances constituting these layers, and to transmit a potential difference produced in the ion-selective layer by contact with an ion from the ion-selective layer to the redox layer.

Abstract: There is disclosed a process for producing a laminar electrode. The method comprises successive superposition of an insulating support, a conductive layer, a stable-potential internal reference element and an ion-selective diaphragm, all of which are protected by a mask which is impermeable to aqueous solutions. A completely tight seal between the mask and the ion-selective diaphragm is formed by casting the diaphragm in the form of a solution containing a binder which dissolves with and intimately mixes with the mask material.

Abstract: The electrode membrane of the invention has high ion-selectivity for lithium ions relative to other alkali and alkaline earth metal ions. The membrane is shaped from a polymeric composition comprising a polymeric material, e.g., a polyvinyl chloride resin and poly(1,2-butadiene), a plasticizer and, as the ion carrier, a derivative of 1,10-phenanthroline such as 2,9-dimethyl-1,10-phenanthroline and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

Abstract: The electrode comprises an internal reference half-cell at stable potential comprising a conductive sheet, e.g. of metal of carbon, covered by a redox system. The redox system comprises a thin dehydrated layer of Prussian blue deposited by contact between the sheet and a mixture of alkaline ferrocyanide and a ferric salt.

Abstract: An analytical composition, electrode and method are useful for the detection of lithium ions in an aqueous liquid. The lithium ion-selective composition comprises a lipophilic group-substituted 1,10-phenanthroline, a compound capable of solvating the phenanthroline, and a supporting matrix. This composition can be used in a lithium ion-selective electrode as a lithium ion-selective membrane. The electrode can also comprise an internal reference electrode.

Abstract: In a device for measuring ion activity in a liquid sample such as a body fluid comprising at least one pair of ion-selective electrodes selectively responsive to a specific ion, a porous liquid distributing member for feeding a liquid sample to one electrode of the pair of electrodes, a porous liquid distributing member for feeding a reference liquid to another electrode of the pair of electrodes and a porous bridge for electrically connecting both liquids to each other, the improvement wherein the liquid distributing members are made of a nonwoven fabric composed of cellulosic long fibers.

Abstract: A real time, on-line ion mesurement system for a solution has continuous monitoring of the physical conditions of the ion electrode and the reference electrode of the system. A dual chamber reference electrode is provided having an inner chamber and electrode for providing an ion measurement reference potential, and an outer chamber and electrode for producing a monitoring potential to detect poisoning of the reference electrode membrane. A first time varying low level signal is applied to the ion electrode and a second time varying low level signal orthogonal to and uncorrelated with the first signal is applied to a solution ground electrode disposed in the solution adjacent the reference electrode, the signals producing a composite common ground current. A pair of cross-correlators extracts the two time varying components from the common ground current for measuring the ion electrode and reference electrode impedances.

Abstract: An apparatus for processing a double face adhesive tape so as to attach at least one member thereto, comprising a roll of the double face adhesive tape having release papers attached to both faces, a drawing out means of the double face adhesive tape from said roll, a slitting means to slit at least the vicinity of one side edge of the upper release paper or the lower release paper of the double face adhesive tape parallel to said side edge, a separating means to separate the slit release paper leaving at least one side portion of the slit release paper attached, and an attaching means to attach at least one member on the exposed face of the double face adhesive tape is disclosed. The drawing out means intermittently draws out the double face adhesive tape from the roll, and a punching means to punch the double face adhesive tape to form hole(s) is further incorporated.

Abstract: An ion-sensitive FET sensor has a MOSFET gate isolating membrane whose surface is covered by an ion-sensitive layer. A redox layer having a redox function is provided between the isolating membrane and the ion-sensitive layer to improve operating stability and speed of response. An electrically conductive layer or a combination of a thin metal film and an electrically conductive layer is provided between the isolating membrane and the redox layer to further improve operating stability, the adhesion of the layers and the durability of the sensor. Also disclosed are optimum materials for use as an ion carrier employed in the ion-sensitive layer.

Abstract: Partition membranes which are permeable to blood electrolytes fabricated from crosslinked polyetherurethane compositions having from 20 to 50% hard segments. The membranes absorb from 50 to 120% of their dry weight of water and have electrolyte diffusion constants of up to 1.times.10.sup.-6 cm.sup.2 /sec. The membranes are included in electrochemical, fiber optic and solid state blood electrolyte sensors to provide blood compatible surfaces and to ensure that blood components deleterious to analysis of electrolyte in the blood remain separated from the sensing elements.

Abstract: An ion selective microelectrode in which the reference solution is an aqueous solution of formamide (or methyl formamide) and in which the ionophore-containing membrane covering the reference solution is PVC dissolved in water-insoluble 3-methylcyclohexanone (or equivalent substituted cyclic ketone). The reference solution may be gelled with PVA and preferably is buttressed to assure against incursion of membrane components.

Abstract: Disclosed is an enzyme sensor for determining a concentration of glutamate comprising an immobilize enzyme acting specifically to a substrate and a transducer for converting the quantitative change of a substance or heat which is produced or consumed during an enzyme reaction to an electrical signal, wherein the enzyme is glutamine synthetase and the transducer is the pH glass electrode or ion-sensitive field-effect transistor (ISFET). The enzyme sensor can be miniaturized and can accurately determine a concentration of glutamate even when it is low.

Abstract: A coated-wire electrode for potentiometrically titrating surfactant molecules having more than ten carbon atoms includes an electrically-conductive core coated with a semipermeable membrane. The membrane matrix includes a polymer a plasticizer and an ion-exchanger material consisting essentially of dimidium bromide-disulphine blue in suitable proportions to be surfactant selective. The membrane is responsive to anionic, cationic and amphoteric surfactants as well as alkoxylated nonionic surfactants.

Abstract: The carbonate ion selective membrane of the invention comprises (a) a polymeric inert support material; (b) a plasticizer effective to solubilize the support material; (c) a quaternary ammonium ion; (d) an ionophore which is preferentially reactive with carbonate ions; and (e) a hydrophobic molecule effective to exclude ions other than carbonate ions. The addition of a hydrophobic molecule to the membrane formulation serves two purposes. First, it assists in the "binding" of the organic constituents to the matrix. Second, it repels charged species, i.e., anions and cations, from the solution phase, thereby improving selectivity to the carbonate species which enters the membrane via selective complexation with the ionophore. The quaternary ammonium ion is preferably a C.sub.7 to C.sub.9 quaternary ammonium ion. In this case, the plasticizer is selected to be one effective to maximize the binding of carbonate ions with the C.sub.7 C.sub.9 quaternary ammonium ions.

Abstract: In a catheter or hollow needle type electrolytic measuring device having a measuring electrode and a gas reference electrode, an arrangement for stabilizing the operation of the gas reference electrode includes a lipophile membrane coating a part of the gas reference electrode which communicates with an electrolyte containing space. A source of gas, preferably in the form of another electrode which release gas at a constant rate from the electrolyte, is arranged in the space opposite the gas reference electrode.

Abstract: A uranyl ion selective electrode having a responsive membrane, an inner reference electrode, and a uranyl ion inner solution is disclosed, in which the responsive membrane is obtained by treating a membrane material with an ion-exchanger comprising at least one uranyl ion complex formed between a uranyl ion and a neutral phosphoric ester or a neutral phosphorous ester as a complexing agent, a diluent excellent in compatibility with the ion-exchanger, and a solvent mediator having affinity for the membrane material. The electrode is excellent in concentration responsiveness, reproducibility, accuracy, and durability and is particularly suitable for use in uranyl ion analysis in the atomic energy industry.

Abstract: Disclosed is a solid-type ion sensor which does not have an internal liquid chamber. The ion sensor has a laminated structure basically includes an electrically conductive substrate, a redox layer having a redox function covering the surface of the electrically conductive substrate, and an ion-selective layer covering the surface of the redox layer. Also provided is an ion sensor of this type having an insulated thermister imbedded so as to contact the redox layer.

Abstract: An ion selective electrode apparatus for measuring ion activity of solution flowing through a conduit, wherein at least one earth electrode is disposed so as to contact the solution. The earth electrode is capable of shunting electrical noise flowing through the conduit to earth. In the preferred embodiment, an ion selective electrode and a reference electrode are disposed along the conduit between two earth electrodes so as to protect the ion selective and reference electrodes from the electrical noise which may be introduced into the ends of the conduit.

Abstract: An improved electrode assembly for measuring ions, such as a pH electrode, and method of forming the same is provided. A plastic support layer with an aperture is mounted over a base member having electrodes. A gelatinized internal solution is mounted in the aperture over the electrodes in a plasticized solution containing a hydrogen ion-responsive material is formed into a paste and is positioned over the gelatinized internal solution and the adjacent surrounding areas of the support layer. When the paste solidifies it forms a thin film plastic ion-selective response membrane that is integrally sealed to the support layer.

Abstract: An electrochemically coupled cofactor modified electrode for mediating the heterogeneous or homogeneous catalysis of a biochemical reaction by an enzyme. The electrode coating comprises mercapto-flavin derivative bonded to the electrode surface. Methods for preparation and use of the modified electrode are also presented.

Abstract: A liquid junction electrode 10 formed from a silicon body 14 and having a glass membrane 22 attached thereto. A reference electrode is constructed by forming the glass membrane 22 from porous glass having a preferable pore size in the range of 40 angstroms to 75 angstroms. The porous glass membrane 22 has a coating 24 of glass containing mobile ions that is electrostatically bonded to the silicon body 14. Alternatively, a glass plug 92 is formed from a paste of ground glass and organic binder that is heated to cause formation of pores and bonding of the glass plug 92 to a silicon body 94. An ion-sensitive electrode is constructed by forming the membrane 52 from an ion-sensitive glass or by filling the pores of the porous glass membrane 22 with an ion-sensitive material.

Abstract: A chemical selective sensor system utilizes admittance modulated to detect the presence of chemicals or chemical species in a fluid. The sensor system includes a film or membrane adapted to pass ions when selected chemicals which are to be detected are present at the membrane surface. The membrane is attached to a hydrophilic layer of material which, in turn, is attached to a transformed layer which is deposited on a base substrate. When the selected chamicals are present in the fluid, the membrane interacts with the chemicals to allow ions, also in the fluid, to permeate the membrane. This ion current in the membrane is transformed or converted by the transformer layer to an electronic current which is measured by an electrical circuit coupled to the transformer layer of material. An alternating current source is coupled at one terminal to the transformer layer and to the measuring circuit, and at another terminal to a circuit return electrode.

Abstract: In a chlorine ion-selective electrode for analysis of chlorine ion in a liquid sample which comprises a silver metal layer, a silver chloride layer and a chlorine ion-selective membrane, superposed in order, the chlorine ion-selective membrane containing a hydrophobic organic polymer as a binder, the improvement wherein the hydrophobic organic polymer is a vinyl acetal polymer such as vinyl butyral or a copolymer of a vinyl acetal and at least one monomer copolymerizable therewith such as a copolymer of vinyl butyral and vinyl alcohol.

Abstract: An ion-sensitive electrochemical sensor comprises an electrode body having an ion-sensitive polymeric membrane coated thereon. The membrane comprises a water-insoluble copolymer having ion exchange sites and has a glass transition temperature greater than about 80.degree. C. The sensor is used to determine ion concentration by contacting it with a test solution and determining the ion concentration as a function of the potential of the electrode.

Abstract: A membrane anchor for an ion-selective electrode may be formed by intersolubilizing an ion-selective membrane lying above a sensing pad with a region of thermoplastic material laterally disposed around the membrane. A first layer of electrically insulating thermoset material lies beneath the thermoplastic material and in intimate contact with an electrically insulating substrate. A second layer of exposed thermoset material lies above the thermoplastic material and contacts the first layer of thermoset material around the entire lateral perimeter of the thermoset material.The membrane anchor may be usefully employed with an ion-selective electrode having an electrically insulating substrate with a substantially planar surface and having non-metallic means for sensing a potential affixed to the surface beneath an ion-sensitive membrane.

Abstract: An electrode for determining the lithium content of a liquid sample to be tested, has a membrane containing a lithium ion selective compound and a plasticizer, the improvement wherein the plasticizer is a liquid, lipophilic dialkyl phthalate compound or a liquid phenyl phenyl ether compound that has a strong electron withdrawing group at an ortho position on one of the phenyl rings. The ion selective compound has the formula: ##STR1## wherein A is an alkyl group having between 8 and 16 carbon atoms, B is an alkyl group having between 1 and 4 carbon atoms, and each C and D is, independently, a hydrogen atom or an alkyl group having between 1 and 16 carbon atoms, provided that both C and D are not alkyl groups having greater than 4 carbon atoms.

Abstract: There are disclosed an ion selective electrode comprising a polyvinyl chloride series resin plate having a through hole; conductive member disposed along the through hole; ion sensitive membrane of a polyvinyl chloride series resin membrane; and a lead wire connected to the conductive member, and the flow type ion sensor comprises a plurality of the ion selective electrodes mutually integrally associated with each other with the interposition of electrical insulating members so that through holes of the respective ion selective electrodes may define a flow passage for a liquid to be measured, and a flow type ion sensor using the same.The ion selective electrode and flow type ion sensor using the same of this invention allow the measurement in a smaller amount of the sample to be measured and are excellect in the adhesion of the ion sensitive membranes, therefore they have effects of a stable potential supply and a prolonged life time, and these industrial merits are highly great.

Abstract: Disclosed is an ion sensor having an ion-sensitive substrate provided within a tube at a position recessed from an open end of the tube and having an ion carrier membrane, which is selectively permeable to an ion of interest, filling the space between the opening of the tube and the surface of the ion-sensitive substrate on the open-end side of the tube. A method of manufacturing the ion sensor includes steps of inserting and retaining the ion-sensitive substrate in the tube, filling the space between the ion-sensitive substrate and the tube with a sol-like ion carrier membrane composition, and gelling the sol-like ion carrier membrane composition.

Abstract: A sensor arrangement for monitoring ionic concentrations in fluids uses anion-selective membrane formed of N,N'-dibenzyl-N,N'-diphenyl-1,2-phenylenedioxydiacetamide suspended in an inert carrier, such as PVC having a high molecular weight. The membrane is disposed on a porous ceramic plug which permits wetting of the side of the membrane facing the plug with an internal fluid of the system, such as saline. The other side of the membrane communicates with the fluid to be assayed, which in certain intravenous embodiments may be the blood of a patient. In one embodiment, the system is provided with a reference electrode which is arranged to communicate with the fluid being monitored via a dialysis membrane. High impedance electronic circuitry produces a signal indicative of the ionic concentration in response to a potential appearing across the reference and sensor electrodes.

Abstract: A novel ion-selective membrane electrode for the determination of phosphate anions. This device possesses an excellent selectivity for phosphate over many common anions such as sulfate, chloride, bromide, iodide, nitrate, and acetate. The unique feature of this electrode is the use of a di-substituted aryl tin compound as the membrane active material. The incorporation of either dibenzyltin dichloride or bis-p-methylbenzyltin dichloride in a plasticized poly(vinyl) chloride membrane results in a selective membrane electrode for phosphate.

Abstract: A process for modifying an oxide surface of a semi-conductor material, for example included in an ISFET, wherein a coating of a polymer is applied to the oxide surface. The polymer is chemically bonded to the oxide surface. Optionally a second coating can comprise metal ion complexing groups. The process can be used for manufacturing an ISFET.

Abstract: A method for measurement of the concentration of a substance diffusable through inert membranes has a measuring electrode of metal, an electrolyte chamber containing electrolyte, a lipophilous membrane partially covering the measuring electrode and located between the measuring electrode and the electrolyte, and a reference electrode, wherein the substance is H.sub.2 O.sub.2, the combined membrane contains lipophilous ions and/or carrier-bound ions, the base membrane is proton impermeable, and the measuring electrode is formed as anode.

Abstract: A sensor and a method are disclosed for the potentiometric determination of the ion content or activity of a sample and the concentration of other components (e.g., glucose, urea, triglycerides, enzymes, drugs) of a sample. The sensor comprises ion-selective electrodes which are held in a frame and have porous material between them; the porous material provides a means to establish ionic flow between the electrodes. Each ion-selective electrode is comprised of a membrane which is selectively permeable to the ion or other substance whose activity or concentration is being determined; a reference electrode; and an internal reference material.

Abstract: An improved dry-operative ion-selective electrode for the determination of sodium ions in aqueous fluids includes a dried internal reference electrode, a dried reference layer and a sodium ion-selective membrane composed of a binder material. The reference layer contains a metal salt and a hydrophilic binder material, and is buffered to a pH of from about 4 to about 8 with a water-soluble, organic dicarboxylic acid. This electrode can be manufactured with significantly less waste and exhibits improved uniformity in performance.

Abstract: An integral ion selective electrode for the analysis of a potassium ion comprising:(I) a support;(II) an electroconductive metal layer such as a silver metal layer;(III) a layer of a water-insoluble salt of said metal such as a silver chloride layer;(IV) an electrolyte layer which comprises crystalline electrolyte salts of cations including a potassium ion and a sodium ion with the same anions as the anion of the water-insoluble salt, said electrolyte layer being substantially free from a binder; and(V) a potassium ion selective layer.

Abstract: An electrically and covalently coupled cofactor modified electrode for mediating the heterogeneous or homogeneous catalysis of a biochemical reaction by an enzyme. The electrode coating comprises an imidazoleflavin derivative covalently bonded to the electrode surface. Methods for preparation and use of the modified electrode are also presented.

Abstract: There are disclosed a process and the product produced by the process, of making an ion selective electrode for chloride. The process features, after forming a metal chloride layer, the step of washing the electrode in an organic acid, inorganic acid, or a solution of a salt of the acids having certain specified properties.

Abstract: A conductive layer is formed on an insulating base, and at least one groove is formed in the conductive layer by cutting a part of the material of the conductive layer so that the conductive layer is divided into at least a pair of portions electrically isolated from each other by the cut groove. Thereafter, an ion selective layer is formed on the conductive layer to cover substantially the entire surface of the conductive layer including the cut groove.

Abstract: In order to produce a sensitive membrane electrode with high selectivity with respect to other anions and lipophilic ions or interfering substances, the membrane is based on an unplasticized polymer matrix whose content of electroactive component is between 50 and 90 percent by weight.

Abstract: A lipid membrane is used as a chemo-receptive transducer for quantitative and semi-quantitative analysis of chemical test species in an electrolyte. The lipid membrane is contacted with an electrolyte containing the test species, and an electrical potential difference is applied across the membrane. From measurements of the trans-membrane ion current variation due to the presence of the test species, a quantitative analysis of the test species may be conducted, on a highly selective basis. Receptors showing a high degree of selectivity towards the test species are included in the membrane.

Abstract: A semiconductor integrated circuit for sensing a physico-chemical property of an ambient includes a pair of semiconductor devices (Q1, Q2) having a similar geometric and physical structure, one device (Q1) being sensitive to the property, the other being insensitive to the property, together with a differential amplifier (A1, A2, A3, A4, A5) having feedback connection to one of the pair of semiconductor devices.

Abstract: An ion-selective electrode for measuring carbonate concentration comprising a conductive metal layer, a halide of said conductive metal layer, a carbonate ion-selective layer containing ion carrier, and a buffer layer containing a hydrophilic polymer binder and a buffer laminated in this order on an electrically insulating support, and a pair of the above electrodes.It is characterized by not having the electrolyte layer containing hydrophilic polymer binder, having the possibility of degradation of the electrolyte layer by the absorption of moisture being extremely little, and having a good stability in the course of time. In the electrode of the invention, the ion-selective layer comprised of hydrophobic organic material is directly laminated on the metal halide layer, the adhesive strength between the metal halide layer and the ion-selective layer is sufficient, the strength of the ion-selective layer is sufficiently great, and which is stable.