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

Abstract: A gas sensor comprising a proton-conductive layer 5 formed of a polymer electrolyte; first and second electrodes 3 and 4 disposed in contact with the proton-conductive layer 5 and having a function of dissociating hydrogen; a gas-diffusion-rate limiting layer 2 disposed between a measurement gas atmosphere and the first electrode 3 and adapted to diffuse the gas under measurement to the first electrode 3 in a diffusion-rate limited state; and a dense support 1 supporting these elements. Hydrogen gas having reached the first electrode 3 via the gas-diffusion-rate limiting layer 2 is dissociated into protons by virtue of the catalytic action of Pt contained in the electrode and the voltage applied to the first electrode 3, and the generated protons are pumped to the second electrode 4 via the proton-conductive layer 5 and are converted to hydrogen gas, which diffuses into the measurement gas atmosphere.

Abstract: An electrophoresis apparatus, comprises a cartridge configured to be removably mounted in the apparatus, and a separation membrane positioned in the cartridge. The separation membrane has a first side along which a first flow path defined in a first grid element and a second side along which a second flow path defined in a second grid element is provided. Restriction membranes separate buffer flow from the first flow path and the second flow path. The apparatus includes connection blocks which house electrodes and inlets and outlets for buffer flow and sample flows. The cartridge is removable from the connection blocks for replacement with another cartridge.

Abstract: An ion sensor and an ion sensor plate provided with an ion sensitive membrane which is characterized in that the ion sensitive membrane contains a material constituting the dissociation equilibrium of Ag/X, and an excessive quantity of an ion sensitive material or an anion scavenger. A coated film of surfactant is provided at the inner face of the passageway communicating with the test liquid-measuring electrode so as to add the surfactant to the test liquid. The plasticizer is added at a ratio of 65 to 80% by weight. The atomic ratio of silver and halogen in the silver halide layer is set to at least 1.2. The particle diameter of the modified silver halide layer is set to at most 1 &mgr;m.

Abstract: A system for measuring the effectiveness of cathodic protection or corrosion resistance comprises a coagulate-filled tube adapted for sensing electrical activity at a first end thereof. A second end of the coagulate-filled tube is in communication with a reference electrode. A voltmeter in communication with the electrode for supplying a reading of a voltage differential. A capillary tube for use in conjunction with a reference electrode extends the reach of the reference electrode. A flexible conduit defines a continuous opening axially therethrough. The flexible conduit contains a conductive hydroscopic electrolyte coagulate such as gelatin or a crosslinked polymer. The conduit is adapted for communication at one end with an electrode that communicates with the coagulate. It is further adapted at a second end for sensing a level of electrical potential in proximity thereto.

Abstract: A solid electrolyte type carbon dioxide gas sensor element has a solid electrolyte layer, a work electrode layer formed on one side of the solid electrolyte layer and containing an electron conducting material and an auxiliary electrode material, and a reference electrode layer formed on the same side or the other side of the solid electrolyte layer and containing an electron conducting material. The work electrode layer further contains a rare earth metal oxide or at least part of the auxiliary electrode material of the work electrode layer is a rare metal oxide carbonate.

Abstract: An array of electrodes at the atomic or nano scale (nanoelectrodes) is built on a chip. The spatial distribution, height, width and electrochemical composition of the nanoelectrodes is varied, such that protein-specific electronic receptors are built directly on the chip with the nanoelectrodes without the use of any specific binding agents or molecules. Because of their size, a very large number of different receptors can be built as arrays on a single chip. The chip can be used to detect, characterize and quantify single molecules in solution such as individual proteins, complex protein mixtures, DNA or other molecules.

Abstract: A method for estimating the concentration of a reduced (or oxidised) form of a redox species in a liquid comprises contacting an area of a first electrode (2) with a sample (5) of the liquid, contacting the sample (5) with a second electrode (2) spaced apart from the first (2), applying a potential between the electrodes while the electrodes are sufficiently closely spaced that reaction products formed at each electrode diffuse to the other electrode while the potential is applied, measuring or estimating a value indicative of the change in current as a function of time and a value indicative of the steady state current, and determining from said volume, said current as a function of time, and said steady state current the concentration of reduced (or oxidised) form of the species in the liquid sample.

Abstract: Magnetic composites exhibit distinct flux properties due to gradient interfaces. The composites can be used to improve fuel cells and effect transport and separation of different species of materials. A variety of devices can be made utilizing the composites including a separator, a cell, an electrode for channeling flux of magnetic species, an electrode for effecting electrolysis of magnetic species, a system for channeling electrolyte species, a system for separating particles with different magnetic susceptibilities. Some composites can be used to make a dual sensor for distinguishing between two species of materials and a flux switch to regulate the flow of a redox species and a flux switch to regulate the flow of a chemical species. Some composites can control chemical species transport and distribution.

Abstract: A gas sensor, in particular for determining the content of gases in the exhaust of an internal combustion engine, has a contact part carrier composed of two opposing, externally symmetrical half-shells, engaging in and contacting the terminal end of a sensor which runs axially and is installed in a tubular protective sleeve, with the half-shells of the contact part carrier being held together by a spring element. The spring element is designed to exert only a low clamping force on the half-shells of the contact part carrier in a first bracing step when the contact part carrier is pre-mounted on the terminal end of the sensor, so that the sensor can still be inserted easily between the two half-shells. In a second bracing step it presses from all sides against the two half-shells due to the inside wall of the protective sleeve and pushes them against the supporting contact points with a greater force than in the first bracing step.

Abstract: An electro-chemical process for rehabilitating steel reinforced concrete, wherein a distributed flow of electrical current is established between internally embedded reinforcing steel, connected as a cathode, and an external, distributed electrode, connected as an anode. Current flow at a rate of at least 0.1 ampere per square meter of surface area of the embedded reinforcement is continued for a time sufficient to provide a total charge of at least about 100, but not substantially more than 2000, ampere-hours per square meter of surface area of the embedded reinforcement. This results in steel with a clean surface, surrounded by concrete which is chloride free and highly alkaline. After discontinuance of the electrochemical treatment, the embedded steel slowly passivates by forming a protective surface oxide. The process is significantly more economical than known procedures, yet is reliably effective.

Abstract: An improved structure of a gas sensor is provided which includes a hollow housing and a sensing element. The sensing element has a flange and is disposed within the housing in engagement of the flange with an inner wall of the housing. An insulating powder is packed in a chamber defined by the inner wall of the housing, the flange and an outer wall of the sensing element to provide an air-tight seal between an air chamber to which one end of the sensing element is exposed and a gas chamber to which the other end of the sensing element is exposed. The air-tight seal has the structure designed to minimize an air leakage and breakage of the sensing element when installed in the housing.

Abstract: A nitrogen oxide sensor enabled to enhance the measurement concentration of a total of nitrogen oxides by oxidizing or reducing the nitrogen oxides on the surfaces of electrodes in addition to the control of an oxygen concentration by an oxygen pump. An electrode (3a) in a gas chamber (18) constructing an oxygen pumping portion (3) is made of a material (e.g., Pt-3 wt % Rh) having a function to oxidize a nitrogen oxide gas.

Abstract: The present invention provides methods for detecting the presence of an analyte indicative of various medical conditions, including halitosis, periodontal disease and other diseases are also disclosed.

Abstract: A sensor, particularly for determining the oxygen content in exhaust gasses of internal combustion engines, includes sensor element which is fixed in a metallic housing and a sealing flange which is integrally formed on the housing and rests on a sealing seat which is formed on an exhaust system. The sealing flange has two ring elements which are integrally formed on the housing and each have an inclined sealing surface, a hollow space being formed between the two ring elements inside the housing.

Abstract: A measuring electrode system having a measuring body 2 (22) replaceably provided on a rotatable shaft (21). The rotating shaft is provided with a spring loaded contact pin (25, 26). When the measuring body is attached to the shaft the electrodes (16, 18) running through the measuring body will be brought in electrical connection with the contact pins.

Abstract: An automotive lambda oxygen sensor is formed by electroless plating of a thin, catalytically active, conductive electrode uniformly on the outer surface of a zirconia thimble. The process includes forming a pristine zirconia solid electrolyte thimble and drilling out a cylindrical cavity in it. A porous outer surface suitable for producing crystallization sites is formed by dipping the unfired thimble in a zirconia slurry containing spray-dried microspheres and firing the coated thimble to densify the thimble and the microspheres and to produce cavities on the surface of the thimble. An inner platinum electrode is formed by conventional conductive ink painting on the axial cavity of the sensor, and the sensor is again fired. The surface is activated by immersion in an acetone chloroplatinic acid bath to form multiple crystallization points, heat treated, then plated in an electroless platinum bath to a desired thickness.

Abstract: A preassembled cathodic protection system is provided for protecting buried structures such as guy anchors, which includes a reference cell, test station and anode, all prewired together and tested before delivery and field installation. The package includes a convenient connection for the structure which has one lead to an exposed stud or contact point on the test station, and another lead from the connection to the anode or anodes through a shunt in the form of a calibrated resistance wire. The shunt is connected to two spaced studs or contact points on the test station by which the shunt is read. The reference cell is also connected to a stud or contact point on the test station. The reference cell-test station lead extends through a flexible tube. The studs or contact points are on the dome or cap of a rigid tube designed to project out of the ground or an electrolyte a short distance. With a guy anchor the tube may include an elow and angled portion.

Abstract: A biosensor is fabricated by forming a metal film over the surface of a substrate through evaporation, sputtering or by gluing a metal foil, then splitting the metal film into three regions, and forming a reagent layer on an area of measuring electrode and two counter-electrodes for placing a liquid sample on by providing a cover disposed over the splitted metal film. As neither of the electrodes are formed through conventional printing technology, the electrodes can be formed without dispersion. As a result, a precision biosensor having excellent response characteristics is implemented.

Abstract: The subject method and apparatus pertains to the accurate determination of a composition of gases, over a very wide range of compositions. The subject invention can utilize an ionic electrolyte (1), which separates gases of different compositions, a source of potential difference (2) which is applied across the ionic electrolyte, means for reversing the current, and means (3) for measuring the respective currents. The ratio of currents is a function of the ratio of the gas compositions on opposite sides of the electrolyte. By varying the applied potential, the sensitivity of the apparatus can be increased.