Abstract: A bilayer lipid membrane (BLM) sensor comprising (1) a gold recording surface, (2) a first lipid layer which is an imperfect layer of a thiolipid which comprises the residue of two phospholipid molecules linked to each end of a disulphide (--S--S--) group, each through an oxyethylene (--O--CH.sub.2 --CH.sub.2) chain which is short enough to allow the thiolipid to become anchored to the gold surface by self-assembly, but long enough to trap an aqueous layer between the gold surface and the bottom of the thiolipid layer, said thiolipid being attached to the gold surface and said imperfect layer being completed by a phospholipid which provides an unattached fluid phase at room temperature, and (3) a second lipid layer of phospholipid. The sensor is especially useful for measuring changes in electrical resistance and/or capacity when it is prepared to contain a receptor protein and an analyte containing an agonist to the receptor is contacted with the bilayer.

Abstract: The present invention relates to a novel method for producing an electrode membrane combination. This novel method employs compounds including a linker lipid for use in attaching a membrane including a plurality of ionophores to an electrode and providing a space between the membrane and the electrode, the electrode being either in part or totally made up of the linker lipid. The linker lipid comprises within the same molecule a hydrophobic region capable of spanning the membrane, an attachment group used to attach the molecule to an electrode surface, a hydrophilic region intermediate said hydrophobic region and the attachment group and a polar head group region attached to the hydrophobic region at a site remote from the hydrophilic region.

Abstract: The present invention relates to novel electrode membrane combination. This novel combination employs compounds include a linker lipid for use in attaching a membrane including a plurality of ionophores to an electrode and providing a space between the membrane and the electrode, the electrode being either in part or totally made up of the linker lipid. The linker lipid comprises within the same molecule a hydrophobic region capable of spanning the membrane, an attachment group used to attach the molecule to an electrode surface, a hydrophilic region intermediate said hydrophobic region and the attachment group and a polar head group region attached to the hydrophobic region at a site remote from the hydrophilic region.

Abstract: Ion selective membranes and ion selective electrode constructions which include ethylene vinyl acetate (EVA), a reduced amount of plasticizer and an ion selective material. The ion selective membranes have a low crystallinity. In certain embodiments, the ion selective membranes may further include polyvinyl chloride (PVC), a salt or a combination thereof. The ion selective membrane can be incorporated into an ion selective electrode construction. Methods of manufacturing the ion selective membranes and ion selective electrode constructions are provided.

Abstract: It is an of this invention to provide an electrochemical measurement cell capable of measuring the concentration of gaseous and charged or neutral compounds in a liquid. Accordingly, the present invention consists in one aspect in an electrochemical measurement cell having a working and a counter electrode surrounded by an electrolyte space filled with an electrolyte with a high viscosity, wherein the electrolyte space is at least partly delimited by a hydrophilic membrane. It has been surprisingly discovered by the present invention that charged or neutral compounds in a liquid, as well as gases, can be determined by means of an electrochemical measurement cell having a hydrophilic membrane and an electrolyte with a high viscosity.

Abstract: The present invention is a sensor cartridge into which sensors are installed. The sensor cartridge allows the sensors to be easily and reliably installed into a blood analyzer. The sensor assembly has an electrical connector mounted on the rear side of the assembly. A plurality of inner walls within the housing locate a pump tube assembly and right angle fluid coupling within the housing. An opening in the housing receives a first boss which extends from the blood analyzer. A capture/release arm has an opening through which the first boss protrudes. The arm is resiliently held in place such that an inner edge of the opening is captured within a ring-like groove in the boss that extends from the blood analyzer when the cartridge is installed in the blood analyzer. A portion of the arm extends beyond the housing to allow an operator to press the arm and thus release the edge of the arm from the groove in the boss.

Abstract: An improved disposable glucose test strip for use in a test meter of the type which receives a disposable test strip and a sample of blood from a patient and performs an electrochemical analysis is made using a working formulation containing a filler, an enzyme effective to oxidize glucose, e.g., glucose oxidase, and a mediator effective to transfer electrons from the enzyme. The working formulation is printed over a conductive carbon base layer to form a working electrode. The filler, for example a silica filler, is selected to have a balance of hydrophobicity and hydrophilicity such that one drying it forms a two-dimensional network on the surface of the conductive base layer. The response of this test strip is essentially temperature independent over relevant temperature ranges and is substantially insensitive to the hematocrit of the patient.

Abstract: Chemical sensors for detecting analytes in fluids comprise first and second conductive elements (e.g. electrical leads) electrically coupled to and separated by a chemically sensitive resistor which provides an electrical path between the conductive elements. The resistor comprises a plurality of alternating nonconductive regions (comprising a nonconductive organic polymer) and conductive regions (comprising a conductive material) transverse to the electrical path. The resistor provides a difference in resistance between the conductive elements when contacted with a fluid comprising a chemical analyte at a first concentration, than when contacted with a fluid comprising the chemical analyte at a second different concentration. Arrays of such sensors are constructed with at least two sensors having different chemically sensitive resistors providing dissimilar such differences in resistance.

Abstract: The invention relates to an electrochemical sensor with interdigital micro-electrodes (1) with structure widths in the sub-.mu.m range. With a twin or multi-pair array of the interdigital micro-electrodes on a substrate (8), the electrochemical detection of molecules with high sensitivity is made possible and further uses for the detection of chemical reaction cycles are made available. The electrodes may be arranged in a micro-channel applied to the substrate having a constant small volume of a few nanoliters. The electrochemical sensor of the invention is suitable for the multiple measurement of the same species of molecule or as a multi-sensitive sensor in chemical analysis and process control in various fields such as biotechnology, environmental protection or health.

Abstract: A biosensor for rapid quantification of a specific component contained in various biological samples with high accuracy has an electrically insulating base, an electrode system including a working electrode and a counter electrode formed on one face of the insulating base, and a reaction layer formed on the insulating base in close contact with the electrode system. The reaction layer contains at least a hydrophilic polymer, a buffer and an enzyme which is separated from the buffer.

Abstract: In a method for calibration of a pH measuring element whose ion-permeable, hydrophilic polymer layer is brought into contact with an aqueous solution prior to calibration, the aqueous solution is displaced or replaced by a gaseous calibrating medium, and residues of the aqueous solution remaining in the ion-permeable polymer layer. The gaseous calibrating medium contains a known amount of at least one component which is acid or basic in aqueous solution which reacts with the remaining residues of the aqueous solution in the polymer layer, such that a defined pH value is established in the polymer layer, which is employed for calibration of the measuring element.

Abstract: A biosensor for measuring gas-phase organic chemicals rapidly and accurately. The biosensor includes a thick film electrochemical device having an insulating substrate, electrodes formed on the substrate, connecting pads for the electrodes and an insulating layer, and a responsive membrane formed on the electrode portion of the electrochemical device. The responsive membrane is provided with a moisture-absorbing gel layer in which an enzyme for reacting with the gas-phase organic chemical is immobilized.

Abstract: The biosensor of this invention can quantify a substrate in a sample liquid by electrochemically measuring the amount of an electron acceptor that has been reduced by electrons generated in a reaction between the substrate and an oxidoreductase. The biosensor has an electrically insulating substrate and an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction. The third electrode can be used merely for detecting a liquid junction, or can be used as both a reference electrode and a liquid junction detecting electrode.

Abstract: The present invention relates to novel compounds used in an electrode membrane combination. These novel compounds include a linker lipid for use in attaching a membrane including a plurality of ionophores to an electrode and providing a space between the membrane and the electrode, the electrode being either in part or totally made up of the linker lipid. The linker lipid comprises within the same molecule a hydrophobic region capable of spanning the membrane, an attachment group used to attach the molecule to an electrode surface, a hydrophilic region intermediate said hydrophobic region and the attachment group, and a polar head group region attached to the hydrophobic region at a site remote from the hydrophilic region.

Abstract: An electrode strip for use in an electrochemical sensor for measuring a compound in a sample is provided, including an electrode support, a reference or counter electrode disposed on the support, a working electrode spaced from the reference or counter electrode on the support, a covering layer defining an enclosed space over the reference and working electrodes and having an aperture for receiving a sample into the enclosed space, and a plurality of mesh layers interposed in the enclosed space between the covering layer and the support, the covering layer having a sample application aperture spaced from said electrodes and said reference electrode spaced from said working electrode at a position remote from and on the opposite side of said working electrode from said aperture.

Abstract: When determining an activity of particular predetermined ions in a sample liquid by use of a device for measuring ionic activity including a pair of ion-selective electrodes which are selectively responsive to particular predetermined ions, a pair of spotting holes through which a sample liquid and a reference liquid are respectively supplied to the ion-selective electrodes and a porous bridge which communicates the spotting holes with each other so as to permit the sample liquid and the reference liquid spotted to the spotting holes to electrically contact with each other, for instance, the sample liquid is first spotted to one of the spotting holes of the device for measuring ionic activity with a first spotting tool, and at least one of the first spotting tool and the device for measuring ionic activity is thereafter moved to remove the first spotting tool away from the device for measuring ionic activity.

Abstract: A measuring device for determining the concentration of low-molecular alcohols in water or acid having the following construction:a porous anode for the electrochemical oxidation of alcohola cathode for the electrochemical reduction of oxygenan ion-conducting membrane arranged between the anode and cathodea diffusion-limiting membrane arranged on the side of the anode facing away from the ion-conducting membrane.

Abstract: A regenerable biosensor probe adapted for positioning in a bioreactor comprises a selectively permeable interface membrane, a porous protein-receiving matrix adjacent to the interface membrane, an indicating electrode, an inlet conduit through which fresh protein conjugate may flow to the protein-receiving matrix, and an outlet conduit through which spent protein conjugate may be removed from the protein-receiving matrix. A selectively permeable interface membrane, which may be used in a biosensor system to separate biochemical, optical or other processes from an analyte matrix comprises a supporting mesh, a perfluorosulfonic acid polymer impregnated substrate and a homogenous film of perfluorosulfonic acid polymer.A method of preparing this interface membrane comprises fixing a substrate on to a supporting mesh to form a substrate membrane, casting a perfluorosulfonic and polymer on the substrate membrane and curing the product to so formed.

Abstract: A solid state, multi-use electrochemical sensor having an electrically nonconductive substrate, a working electrode, and a semi-permeable membrane covering the working electrode. The working electrode includes an electrically conductive material adhered to a portion of the substrate. A first portion of the conductive material is covered with an electrically insulating dielectric coating, and a second portion of the conductive material is covered with an active layer. The active layer includes a catalytically active quantity of an enzyme carried by platinized carbon powder particles, which are distributed throughout the active layer. A sensor package for incorporating a sensor is provided.

Abstract: An enzyme electrode, specific binding or the like electrochemical assay method capable of performing always stably high detection sensitivity (responsibility) and reappearance even in the case of blood, urine and the like samples that contain interfering substances and also of applying suitably to disposable use, and a novel p-phenylenediamine compound which is used in the assay method.

Abstract: A polymeric membrane electrode gives potentiometric responses to macromolles, such as protamine, in solution or biological specimens. A protamine-responsive membrane includes a lipophilic cation-exchange material for ionic macromolecules in a specially formulated plasticized, polymeric matrix material. Potentiometric response to protamine has been observed in membranes comprising 30-70 wt. % polymeric matrix material, such as polyvinyl chloride; 1-3 wt. % salt of a tetraphenylborate, such as potassium tetrakis(4-chlorophenyl) borate or salt of an organophosph(on)ate, such as calcium bis-[4-(1,1,3,3-tetramethylbutyl)phenyl] phosphate; and 30-70 wt. % of a plasticizer, such as 2-nitrophenyl octyl ether or tris (2-ethylhexyl) phosphate.

Abstract: Screen printing technology is employed in the batch fabrication of the contacts and polymeric membranes of solid-state ion-selective sensors. The process achieves high yield with very reproducible results. Moreover, membrane thickness can easily be predetermined, as it is directly related to the thickness of the screen or stencil. The process of the present invention is compatible with many integrated circuit manufacturing technologies, including CMOS fabrication. Advantageous polymeric membrane paste compositions include a polyurethane/hydroxylated poly(vinyl chloride) compound and a silicone-based compound in appropriate solvent systems to provide screen-printable pastes of the appropriate viscosity and thixotropy.

Abstract: The invention relates to the amperometric detection of nitrite ions and nitrogen monoxide by electrocatalytic reduction by means of electrodes (15) modified by an electronically conductive polymer film such as poly-(N-methyl pyrrole) doped by mixed heteropolyanions of formulas:[M.sup.III X.sup.1 W.sub.11 O.sub.39 (H.sub.2 O)].sup.n- or[M.sup.III X.sub.2.sup.2 W.sub.17 O.sub.61 (H.sub.2 O)].sup.7-in which M represents Fe, Rh, Al, Ga, In or Tl,X.sup.1 represents P or As and n is equal to 4,X.sup.1 represents Si or Ge and n is equal to 5, orX.sup.1 represents B and n is equal to 6, andX.sup.2 represents P or As.It also relates to the films and modified electrodes used.

Abstract: An electrode sensor which may be used to specifically and quantitatively measure nitric oxide is provided, as well as a method of preparing and using such an electrode sensor to measure nitric oxide concentration in solution. A nitric oxide (NO) microsensor based on catalytic oxidation of NO comprises a thermally-sharpened carbon fiber with a tip diameter of about 0.5-0.7 .mu.m coated with several layers of p-type semiconducting polymeric porphyrin and cationic exchanger deposited thereon. The microsensor, which can be operated in either the amperometric, voltammetric or coulometric mode utilizing a two or three electrode system, is characterized by a linear response up to about 300 .mu.M, a response time better than 10 msec and a detection limit of about 10 nM. The sensor of the present invention also discriminates against nitrite, the most problematic interferant in NO measurements.

Abstract: The invention relates to an ion-selective electrode and to a procedure for producing the electrode. The electrode is a single-piece all-solid-state electrode comprising a conducting or semiconducting solid substrate (6) coated with a composite membrane (4). The electrode is produced by dissolving a conjugated polymer or oligomer together with the components of a conventional ion-selective membrane to produce a solution, applying this solution to an electronically conducting or semiconducting substrate and allowing the solvent to evaporate, with the result that a composite membrane is formed on the substrate.

Abstract: A solid state, multi-use electrochemical sensor having an electrically nonconductive substrate, a working electrode, and a semi-permeable membrane covering the working electrode. The working electrode includes an electrically conductive material adhered to a portion of the substrate. A first portion of the conductive material is covered with an electrically insulating dielectric coating, and a second portion of the conductive material is covered with an active layer. The active layer includes a catalytically active quantity of an enzyme carried by platinized carbon powder particles, which are distributed throughout the active layer. A sensor package for incorporating a sensor is provided.

Abstract: An ion concentration measuring apparatus for measuring the concentration of a measuring ion in a sample solution containing the measuring ion and an interfering ion having the same ionic charge number as that of the measuring ion. This apparatus comprises a first ion-selective electrode for generating a potential in response to the measuring ion, and a second ion-selective electrode in response to the interfering ion. The first ion-selective electrode is brought about in contact with a first, second and third standard solutions, each containing known concentrations of ions. A selectivity coefficient of the ion-selective electrode is calculated on the basis of the output potential of the first ion-selective electrode. The first and second ion-selective electrodes are brought about in contact with the sample solution.

Abstract: A biosensor for quantification of a specific component contained in various biological samples comprises an electrically insulating base plate, an electrode system including a working electrode and a counter electrode which are provided on the electrically insulating base plate, a reaction layer formed on the electrode system including at least an oxido-reductase, and an enclosure member having a hollow space constituting a sample supplying channel on the electrically insulating base plate, wherein substantially the whole of the reaction layer is exposed to the hollow space.

Abstract: Chemical sensors for detecting analytes in fluids comprise first and second conductive elements (e.g. electrical leads) electrically coupled to and separated by a chemically sensitive resistor which provides an electrical path between the conductive elements. The resistor comprises a plurality of alternating nonconductive regions (comprising a nonconductive organic polymer) and conductive regions (comprising a conductive material) transverse to the electrical path. The resistor provides a difference in resistance between the conductive elements when contacted with a fluid comprising a chemical analyte at a first concentration, than when contacted with a fluid comprising the chemical analyte at a second different concentration. Arrays of such sensors are constructed with at least two sensors having different chemically sensitive resistors providing dissimilar such differences in resistance.

Abstract: The present invention provides sensing electrodes and electrode assemblies for use in measuring the activity of ions in a fluid sample; measuring blocks which include a sensing module housing such sensing electrodes and a reference electrode; and a fluid analysis system which includes such measuring blocks.

Abstract: The present invention relates to a system for detecting, in a reliable, precise and highly sensitive manner, biochemical agents such as enzymes that catalyze a redox potential change. One electrode is used to measure redox potential changes in an aqueous electrolyte containing the biochemical agents. Another electrode is used to deliver a feedback current to the electrolyte in response to measured Changes in electrolyte redox potential. The amount of feedback current or charge delivered through the electrode to the electrolyte is sufficient in magnitude to maintain a constant redox potential. Quantitation of the amount of feedback current or charge necessary to maintain the constant redox potential may then be used to determine the amount of biochemical agents present. Alternatively, the redox potential need not be kept constant, but instead may be allowed to reach a new steady-state.

Abstract: A planar bicarbonate sensor has been discovered that has a dried residue internal electrolyte layer comprising a bicarbonate source and a halide salt of potassium, lithium, or sodium. The flow-through sensor is capable of providing bicarbonate level of a liquid sample, and when coupled with a pH sensor, may be used to determine the partial carbon dioxide level in the sample. The sensor provides many commercially desirable characteristics including an adequate lifetime, good response time, and good stability upon first usage.

Abstract: A solid state ion-selective electrode device to detect a selected ion species in solution an electrode consisting of a homogeneous solid mixture. The mixture is a solid electrolyte composition possessing ionic conductivity and polyvinyl chloride, and optionally graphite. The electrode is substantially free of metallic silver. An electrical connection operates as a contact between the electrode device and a reference source. Methods for detecting the selected ion species in solutions, such as biological samples utilizing the above described electrodes, are also disclosed.

Abstract: An electrochemical sensor cartridge with at least three reservoir cells, the floor of each cell in leakproof contact with the surface of an electrode assembly whose conductivity is affected by the presence of an analyte in that cell.

Abstract: A glucose sensitive FET sensor is provided which includes a substrate, a source electrode formed in the substrate, a drain electrode formed in the substrate, a hydrogen ion sensitive film formed on the substrate to cover the source electrode and the drain electrode, and a thin enzyme immobilized membrane formed on the hydrogen ion sensitive film and containing glucose oxidase and gluconolactonase. Also provided is a method of producing a glucose sensitive FET sensor which includes the steps of preparing an enzyme immobilized membrane as a thin film containing glucose oxidase and gluconolactonase and forming the membrane on a hydrogen ion sensitive film which is formed on a substrate to cover a source electrode and a drain electrode, both of which are formed in the substrate.

Abstract: A method for making a sensing element for use in a sensor or biosensor that amperometrically measures the concentration of an analyte in a liquid, includes the following sequential steps: a) obtaining an electrode; b) immersing the electrode in a solution of monomer that is capable of being electropolymerized into an electrically insulating polymer; c) flowing an electric current from a cathode through the solution to the electrode at a voltage and amperage sufficient to cause the monomer to polymerize on the surface of the electrode, thereby yielding an electrode coated with an adherent layer of electrically insulating polymer; and e) impregnating the polymeric coating on the surface with a sensing agent that is capable, when contacted by a specific analyte in a chemical or biological liquid, of generating an electroactive molecule that can be detected amperometrically.

Abstract: An amperometric biosensor for the detection of an affinity reaction is described. The sensor includes an electrode having on its testing surface a hydrogel in which a selective binding unit and redox species are immobilized.

Abstract: This invention relates to a process for performing enhanced selectivity potentiometric ion determinations using an asymmetric ion membrane electrode having an asymmetric membrane with a hydrophilic layer fused to an ion-selective layer.

Abstract: A gas sensor including an electrochemical sensor cell which has a anion-eange solid polymer electrolyte membrane with three attached electrodes is provided. The sensor cell contains no liquid electrolyte and is operated in the potentiostatic as well as the potentiodynamic modes to detect alkaline reactive gases, including vapors, such as hydrazines and derivatives thereof and ammonia. These sensor cells together with electronic circuitry, a pump and a power supply, fit into a compact, pocket-sized container to define the gas sensor of the invention which can detect traces of the above gases including 10 ppb of hydrazine and its derivatives and 10 ppm of ammonia. The invention includes the above gas sensor and the methods of operating same.

Abstract: This invention relates to sodium-selective agents which are monensin amide derivatives and sodium-selective electrodes having sodium-selective membranes containing such monensin amide derivatives. This invention further relates to multisensor flow assemblies incorporating such a monensin amide derivative in a sodium-selective electrode.

Abstract: A redox electrode for the rapid detection of glucose in aqueous media and a method for its use are provided. The redox electrode comprises an electrically conductive member such as copper, and a redox membrane in direct contact with said electrically conductive member. The redox membrane comprises a polymer matrix such as PVC containing a plasticizer, and a complex of 7,7,8,8 -tetracyanoquinodimethane and tetrathiafulvalene with the complex having a burgundy-red coloration and characterized by a broad absorption from about 340 nm to about 550 nm and weaker absorption between about 650 nm to about 800 nm having about six small peaks with an absorption maximum at about 750nm. Glucose is rapidly assayed by bringing the redox electrode and a reference electrode into simultaneous contact with an aqueous medium containing KCl, phosphate buffer, glucose oxidase, peroxidase, and 3,3',5,5'-tetramethylbenzidine dihydrochloride. The potential of the redox membrane is then monitored until it is stable.

Abstract: A sensitive and rapid electrochemical sensor monitors motor oil deterioration, particularly antioxidation property, by determining the antioxidant and antiwear agent level remaining in an oil formulation. The electrochemical sensor is a two- or three-electrode electrochemical cell having a conductive electrolyte liquid or gel-like interphase over the electrode surfaces. The degree of deterioration of a motor oil in service is monitored by measurements of antioxidation or antiwear capacity of the oil. The electrochemical sensor can be used for monitoring other lubricants and hydrocarbons which contain electroactive additives. The electrochemical sensor allows measurements to be performed in-situ, without any chemical or physical pretreatment of the oil.

Abstract: The solid-state ion sensor of the present invention comprises an inner electrode comprising a metal and a water-insoluble salt of the metal which covers at least a part of the surface of the metal, an ion-selective membrane selectively responsive to the ion species to be determined, and an intermediate layer comprising a hydrophilic polymeric membrane provided between the inner electrode and the ion-selective membrane. The inner electrode comprises a metal and a halogenide of the metal which covers at least a part of the surface of the metal. In the hydrophilic polymeric membrane is dispersed a hydrophilic electrolyte having halogen ions same as or different from those constituting the halogenide with the weight ratio of the electrolyte and the polymer [(electrolyte) wt. %/(polymer) wt. %] being at least 1/100. A polymeric ion-conductor can be used as the hydrophilic polymeric membrane.

Abstract: A biological oscillating device comprises a lipid-impregnated membrane which is disposed in an electrolyte solution and in which is buried an ion channel having a selectivity opposite to that of the lipid-impregnated membrane, and an electrode provided for transmitting a membrane potential of the lipid-impregnated membrane in the form of an electrical signal. When a membrane potential is caused across the lipid-impregnated membrane by the application of an electric current via an eletrode, or by the activation of the ion pump, an ion pump, an ion channel opens once the magnitude of the membrane potential reaches the active potential of the ion channel, whereby the membrane potential is accordingly eliminated. Upon the elimination of the membrane potential, the ion channel is closed to allow the membrane potential to be again raised. Then, once reaching the active potential of the ion channel, the ion channel reopens so that the membrane potential is correspondingly eliminated.

Abstract: A carbon electrode is dipped in a solution containing a reactive substance, and the carbon electrode impregnated with the solution is covered with an insulating tubular member; or a solution containing a reactant is poured into an insulating tube, and a carbon electrode is inserted into the tube; whereby the reactant is made coexistent in the periphery of the carbon electrode. Alternatively, a reactive substance such as an active enzyme and graphite particles or activated carbon particles are mixed with a liquid and dispersed therein to prepare a thoroughly wetted paste. The paste is introduced by means of an extruding mechanism such as a syringe into an insulating tubular member in which a bundle of many thin carbon rods as a lead is inserted. Thus, a carbon sensor electrode is produced. Alternatively, a first carbon electrode that has been dipped in an active enzyme or an enzyme-like reactive substance solution is disposed in a wet condition in a cylindrical ion permeable membrane.

Abstract: A procedure and an apparatus to determine the concentration of dissolved ammonia. A polypyrrole electrode (2), a reference electrode (1) and an auxiliary electrode (5) are placed in the liquid to be analyzed and the concentration of ammonia dissolved in the liquid is determined by a potential applied between the polypyrrole electrode (2) and the reference electrode (1) and of the current flowing between the polypyrrole electrode (2) and the auxiliary electrode (5). A polypyrrole layer (4) is formed on a platinum substrate (3).

Abstract: On the bottom face of a measurement section, measurement electrodes and a reference electrode are formed and a solution supply pipe is opened. Then, if a predetermined electrolytic solution is supplied from the solution supply pipe, the electrolytic solution can be held on an electrolytic solution holding surface on the lower end of the measurement section, utilizing the surface tension thereof for providing a gas reception portion. Since the electrolytic solution is exposed directly to the air, substances in a vapor phase (particularly, odor substances) are diffused into the electrolytic solution, causing an electric state to change. The substances in the vapor phase can be detected by detecting the electric state change. The electrolytic solution held on the lower face of the measurement section can be updated by further supplying more electrolytic solution.

Abstract: A solid state, multi-use electrochemical sensor having an electrically nonconductive substrate, a working electrode, and a semi-permeable membrane covering the working electrode. The working electrode includes an electrically conductive material adhered to a portion of the substrate. A first portion of the conductive material is covered with an electrically insulating dielectric coating, and a second portion of the conductive material is covered with an active layer. The active layer includes a catalytically active quantity of an enzyme carried by platinized carbon powder particles, which are distributed throughout the active layer. A sensor package for incorporating a sensor is provided.

Abstract: A sensor device is disclosed for identification of a gaseous component in a gaseous or liquid sample. The sensor device comprises an optode membrane having sensitivity for the gaseous component to be identified. The optode membrane incorporates two ionophores, at least one of which is a chromoionophore capable of changing absorption spectrum. The sensor device further comprises a hydrophobic gas-permeable membrane, one side of which is positioned upon the optode membrane to prevent direct contact of the optode membrane with the liquid or gaseous sample while still permitting passage of the gaseous component to be identified. As a result, ionic compounds incapable of passing through the lipophilic gas-permeable membrane do not interfere with the identification process leading to a highly sensitive sensor.

Abstract: A miniaturized oxygen electrode comprising: an electrically insulating substrate; an electrolyte-containing material disposed on the substrate to form an electrolyte solution when water is introduced thereto; a set of component electrodes disposed on the substrate and connected with each other via the electrolyte-containing material; a gas-permeable membrane covering the electrolyte-containing material; the set of component electrodes including a cathode on which a reduction reaction of oxygen occurs and an anode as a counterpart of the cathode; the electrolyte-containing material being composed of a first layer and a second layer which are mutually connected, the first layer containing no electrolytes and being connected to the cathode and the second layer containing an electrolyte and being not connected to the cathode, the mutual connection of the first layer and the second layer being effected so that, during the water introduction and a subsequent holding, the electrolyte of the second layer diffuses to