Abstract: An electrochemical cell comprises a cell body having a sample chamber, a working electrode fitted through the cell body and extending into the sample chamber; a counter electrode extending through the cell body into the sample chamber; a reference electrode extending through the cell body into the sample chamber; a window which fits over the cell body; and a cap threaded to the cell body for sealing the window against the cell body. An O-ring fitted between window and the cell body provide a leak proof seal. The cell body may be to made of chemically resistant material and be small enough to fit inside the sample chamber of a spectrometer. An O-ring interposed between the cell body and window provides a leak-tight seal, obviating the need for epoxy cement or other sealing compounds so that the cell may be easily disassembled. The cell may be used to monitor electrochemical reactions of moisture and oxygen sensitive materials, as well as electrochemical reactions of corrosive materials.

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 present invention provides an electrochemical sensor for the detection of hydrogen cyanide. In general, the electrochemical sensor includes a housing having disposed therein a working electrode, a reference electrode and a counter electrode. The electrochemically active surfaces of the working electrode and reference electrode preferably comprise silver. Electrical connection is maintained between the working electrode and the counter electrode via an organic electrolyte present within the housing. The electrochemical gas sensor preferably further comprises circuitry for maintaining the working electrode at a potential in the range of approximately +40 mV to approximately -40 mV versus the silver reference electrode. Most preferably, the electrochemical gas sensor comprises circuitry for maintaining the working electrode at a potential of approximately 0 mV versus the silver reference electrode. The present invention also provides a method of using such a sensor to detect hydrogen cyanide.

Abstract: A method for measuring the concentration of glucose diffused from a source to a working electrode which assembly includes a scavenging electrode is disclosed. The electrode of the invention is comprised of 1) a working electrode; 2) a scavenging electrode; 3) an electroosmotic electrode; and 4) a electrically insulating gap defined by adjacent edges of 1) and 2) and electrically isolating 1) and 2). The scavenging electrode substantially reduces or eliminates "edge-effects" or error in signal transported to the working electrode via a path which includes a radial vector component, i.e., eliminates chemical signal other than that which moves to the catalytic surface of the working electrode via a path which is substantially perpendicular to catalytic surface of the working electrode.

Abstract: A gas sensor assembly having a first housing portion having a receptacle formed therein and a second housing portion in the form of a cover. A gas-sensing agent is disposed in the receptacle, and a working electrode, a counter electrode, and a reference electrode provided on a single electrode support sheet are disposed in fluid contact with the gas-sensing agent. The first housing portion is provided with three conductive housing portions which are in electrical contact with the three electrodes, and the cover maintains pressurized contact between the three conductive housing portions and the three corresponding electrodes. The gas sensor may be provided with two different types of leakage detectors to sense leakage of the gas-sensing agent from the sensor.

Abstract: Methods are described for extending the service life of implantable sensors having a silver-containing anodic reference electrode maintained at a high impedance, at least one noble metal cathodic working electrode, and at least one noble metal anodic counter electrode maintained at a low impedance, particularly sensors for the in vivo detection of oxygen and/or glucose in bodily fluids. The methods described involve increasing the input impedance of the reference electrode up to a maximum for implanted circuitry and shielding said electrode, and/or alternating the operating roles of the reference and working electrodes, switching the working electrodes with counter electrodes in the circuit, reversing the polarities of the reference and working electrodes, and sequentially activating each electrode in a plurality of working and/or reference electrodes in the circuit.

Abstract: A high sensitivity multiple waveform voltammetric method and instrument are provided for use in electrochemical and other applications. The method consists of applying one or several variable potential excitation signals between electrodes of an electrochemical cell to produce an electrochemical reaction in the solution. The excitation signals include a DC bias potential increasing cyclically by a potential step to form a potential staircase signal sweeping across a potential domain, and a number of pulse trains either of opposite polarity or shifted in potential per potential step. An electric current derived from a diffusion flux of ions through the solution is measured as a result of the applied excitation signal.

Abstract: An improved biologic electrode array and methods for manufacturing and using the same. In one aspect, a matrix of electrodes each coupled to a respective sample-and-hold circuit is provided. The electrodes and sample-and-hold circuits are integral and form an array within a single semiconductor chip, such that each sample-and-hold circuit may be loaded with a predefined voltage provided by a single, timeshared digital-to-analog converter (DAC). Further, all of the sample-and-hold circuits may be accessed through a multiplexer which may be scanned through some or all of the electrode locations. Each sample-and-hold circuit may comprise a capacitor and one or more transistor switches, the switch(es), when closed, providing electrical communication between the capacitor and a source line formed in the matrix.

Abstract: The invention relates to an electrochemical sensor to determine the concentration of a gas to be quantified, comprising a housing, a measuring electrode comprising a catalystically active material which causes a reaction of the gas to be quantified, a counterelectrode comprising a carbon material, and a solid electrolyte in contact with the measuring electrode and the counterelectrode, wherein the solid electrolyte is prepared by swelling a solid matrix comprising an acrylate polymer with an electrolytic solution comprising at least one acid, and wherein the carbon material in the counterelectrode has a specific surface of at least 40 m.sup.2 /g and comprises reversibly oxidizable or reducible electrochemically active surface compounds.

Abstract: A method and apparatus for determining the quantity of a substance in a solution. An exemplary embodiment of the method includes the step of introducing a first sample of the solution into a cavity in which a working electrode is located. A constant potential is applied between the working electrode and a reference electrode in electrical contact with the first sample until such time as the current through the working electrode has decayed to a minimum. The applied constant potential is maintained as the first sample of the solution is replaced by a second sample of the solution in a manner such that the cavity remains filled with solution during the replacement procedure. The applied constant potential is maintained until such time as the current through the working electrode has again decayed to a minimum, and the total amount of the charge passing through the working electrode subsequent to the introduction of the second sample into the cavity is determined.

Abstract: An in-situ procedure is described for measuring chlorate ion concentration in aqueous media containing the same by employing electrodes, particularly microelectrodes which generate a sigmoidal-type response at high chlorate ion concentration, and which exhibit catalytic properties toward chlorate ion electroreduction or electrooxidation.

Abstract: Accordingly, the present invention provides an electrochemical sensor comprising at least two electrochemically active electrodes, a non-aqueous electrolyte system and a diffusion barrier membrane through which the analyte in its gas phase is mobile but through which the non-aqueous electrolyte system is substantially immobile. The diffusion barrier membrane thus allows an analyte in its gas phase to enter the sensor, while substantially preventing the non-aqueous electrolyte from exiting the sensor.

Abstract: A new electrochemical probe(s) design allowing for continuous (renewable) reagent delivery. The probe comprises an integrated membrane-sampling/electrochemical sensor that prevents interferences from surface-active materials and greatly extends the linear range. The probe(s) is useful for remote or laboratory-based monitoring in connection with microdialysis sampling and electrochemical measurements of metals and organic compounds that are not readily detected in the absence of reacting with the compound. Also disclosed is a method of using the probe(s).

Abstract: An electrochemical measuring cell for the simultaneous detection of different gas components in a gas sample, with a plurality of measuring electrodes (4, 5, 6) behind a diffusion barrier (7), with a common reference electrode (8) and counterelectrode (9) in an acid electrolyte, and with a potentiostatic evaluating circuit. Improvements in terms of service life for a sensor for the simultaneous detection of oxygen and carbon monoxide is provided with a reference electrode formed of a sintered mixture of metal and its metal oxide, preferably from the platinum group, the iridium group or gold and the potential of the CO-measuring electrode (5) relative to the reference electrode (8) is set at about 0 to 300 mV, and that of the O.sub.2 -measuring electrode (4) is set at a value between -300 and -800 mV.

Abstract: A gas sensor including a substrate that is porous at least in a region thereof to permit permeation of gas. At least first and second porous electrodes are formed as planar elements on the substrate. The substrate is bonded to a housing in a peripheral area of the sensor. A portion of the first electrode extends into this peripheral area and is rendered non-porous to prevent the leakage of electrolyte therethrough.

Abstract: The present invention provides an electrochemical sensor for the detection of hydrogen chloride. In general, the electrochemical sensor comprises a housing having disposed therein a working electrode, a reference electrode and a counter electrode. The electrochemically active surface of the working electrode preferably comprises a gold film having a thickness of approximately 1000 to 3000 .ANG.. Electrical connection is maintained between the working electrode and the counter electrode via an electrolyte present within the housing. The electrochemical gas sensor preferably further comprises circuitry for maintaining the working electrode at a potential in the range of approximately 1025 to approximately 1400 mV versus the normal hydrogen electrode. The present invention also provides a method of using such a sensor to detect hydrogen chloride.

Abstract: The present invention provides an electrochemical gas sensor for the detection of nitrogen dioxide comprising a housing and a working electrode and a counter electrode disposed within the housing. Each of the working electrode and the counter electrode are fabricated from an electrically conductive carbon. The present sensor also preferably comprises a reference electrode fabricated from an electrically conductive carbon.

Abstract: A field effect transistor (10) for chemical sensing by measuring a change in a surface potential of a gate electrode (48) due to exposure to a fluid has a semiconductor substrate (12) with a trench (18,20). The trench has a first sidewall (30) and a second sidewall (32) disposed opposite the first sidewall to provide a fluid gap (50) for the fluid to be sensed. The gate electrode is disposed overlying the first sidewall of the trench, and a source region (54) and a drain region (56) are disposed in the second sidewall of the trench. A channel region (52) is disposed between the source and drain regions, and the gate electrode is disposed opposite the first channel region across the fluid gap. A heater (26) for regulating the temperature of the gate electrode is disposed in the first sidewall of the trench.

Abstract: An electrochemical measuring sensor for selectively determining nitrogen oxides in a gas mixture including oxygen and nitrogen oxides, includes a solid electrolyte layer; a cover layer; and a diffusion channel which is defined between the solid electrolyte layer and the cover layer, and through which the gas mixture diffuses in a diffusion direction. The solid electrolyte layer has provided on a surface thereof a first cathode and a second cathode disposed one after the other in the diffusion direction of the gas mixture within the diffusion channel and exposed to the gas mixture in the order recited, and has provided on an opposite surface thereof at least one anode. The diffusion channel forms a diffusion barrier for the second cathode. The first and second cathodes and the at least one anode are gas permeable and consist of one of a precious metal or a precious metal alloy. The first cathode is provided with a coating which completely covers same, which is impermeable to nitrogen oxides (NO.sub.

Abstract: An electrochemical oxygen sensor comprises an impermeable substrate and a plurality of conductive layers applied thereto by thick film deposition. At least one conductive layer comprises an electrode and a conductor connected to the electrode. The electrode may have a covering layer of an ion exchange polymer.

Abstract: A sealing ring containing an electrode for sensing electrochemical conditions within a fluid handling system, in particular, the occurrence of crevice corrosion, has a body formed of a continuous loop of an electrically insulating fluid-impervious material having a surface which can form a fluid-tight seal with elements of a fluid handling apparatus, an electrode embedded within the body and electrically insulated from electronic conductive contact with those portions of the surface of the body that contact the fluid handling apparatus, and channels extending between the electrode and the surface of the body of the sealing ring to permit electrochemical contact between the electrode and the fluid within the system. The sealing ring also includes electronically conductive wires to connect the embedded electrode to external electrical devices, e.g., electronic measuring equipment.

Abstract: The invention is directed to an electrochemical measuring cell to detect different gas components. The measuring cell includes several measuring electrodes (12, 15, 18) and a counter electrode 30 in an aqueous electrolyte 3. The measuring cell is improved with respect to the selectivity of the detection of the different gaseous components. A step-like offset 34 is provided between one of the measuring electrodes 12 and another measuring electrode 15.

Abstract: A microsensor for electrochemical measurements allowing the determination of concentration or concentration profile of at least one chemical compound with small size or molecular weight, under organic, inorganic, neutral or ionic form in an aqueous environment. The microsensor comprises an array (15) of microelectrodes (16), assembled on a chip (10) supported by an isolating substrate (7), and linked with at least one conductor protected by an insulating layer to a contact allowing the connection to a measuring apparatus. The said microsensor is totally coated with an hydrophilic gel (25) which is chemically inert with respect to the chemical compound, is hydrated at a level of at least 70 %, and has a thickness superior to 10 times the size of the microelectrodes (16). And an integrated electrochemical microsystem including the microsensor.

Abstract: The present invention is an electronic wiring substrate for sensors formed over a subminiature through hole. Because of the small diameter of the through hole, the material that fills the through hole and the through hole itself have an essentially negligible effect on the sensor. Only a small amount of conductive material which fills each through hole is in contact with each associated electrode. Therefore, the purity of the electrode is not significantly altered by the conductive material coupled to the electrode. A relatively large number of sensors can be formed on the surface of the substrate within a relatively small fluid flowcell. Thus, more information can be attained using less blood. The substrate is essentially impervious to aqueous electrolytes and blood over long periods of storage in potentially corrosive environments.

Abstract: A method for determining the presence of a first gas in a second gas uses a gas sensor made up of at least two pairs of electrodes, each pair of electrodes having different spacing between the electrodes. The electrodes of the gas sensor have surfaces that are reactive to the gases under investigation. The gas sensor is exposed to the gases, and the electrical resistances between the pairs of electrodes are measured over a period of time. `The results are compared with a calibration curve to determine if the first gas is present in the second, and to determine of the sensor is malfunctioning.

Abstract: Chemical mechanical polishing slurry characteristics, such as oxidant concentration and abrasive particle dispersion, are determined using electrochemical measurement techniques, such as chronoamperometry, amperometry, chronopotentiometry, ionic conductivity, or linear sweep potentiometry. Slurry characteristics may be tested and monitored independent of a CMP polishing tool. Slurry characteristics may also be automatically controlled in an on-line chemical mechanical polishing process using electrochemical measurements.

Abstract: An efficient method for the microfabrication of electronic devices which have been adapted for the analyses of biologically significant analyte species is described. The techniques of the present invention allow for close control over he dimensional features of the various components and layers established on a suitable substrate. Such control extends to those parts of the devices which incorporate the biological components which enable these devices to function as biological sensors. The materials and methods disclosed herein thus provide an effective means for the mass production of uniform wholly microfabricated biosensors. Various embodiments of the devices themselves are described herein which are especially suited for real time analyses of biological samples in a clinical setting. In particular, the present invention describes assays which can be performed using certain ligand/ligand receptor-based biosensor embodiments.

Abstract: An efficient method for the microfabrication of electronic devices which have been adapted for the analyses of biologically significant analyte species is described. The techniques of the present invention allow for close control over the dimensional features of the various components and layers established on a suitable substrate. Such control extends to those parts of the devices which incorporate the biological components which enable these devices to function as biological sensors. The materials and methods disclosed herein thus provide an effective means for the mass production of uniform wholly microfabricated biosensors. Various embodiments of the devices themselves are described herein which are especially suited for real time analyses of biological samples in a clinical setting. In particular, the present invention describes assays which can be performed using certain ligand/ligand receptor-based biosensor embodiments.

Abstract: An electrochemical gas sensor comprising a sensing electrode, a counter electrode, an electrolyte reservoir, an upwardly extending projection disposed within the reservoir that supports the counter electrode, and a wick interposed between, and in contact with, the sensing and counter electrodes. The wick includes an overhang partially disposed in the electrolyte reservoir. The sensor may further include a reference electrode coplanar with and adjacent to the counter electrode. The sensor is accurate and sensitive, while also compact, reliable, and relatively simple to manufacture.

Abstract: A gas sensor assembly having a first housing portion having a receptacle formed therein and a second housing portion in the form of a cover. A gas-sensing agent is disposed in the receptacle, and a working electrode, a counter electrode, and a reference electrode provided on a single electrode support sheet are disposed in fluid contact with the gas-sensing agent. The first housing portion is provided with three conductive housing portions which are in electrical contact with the three electrodes, and the cover maintains pressurized contact between the three conductive housing portions and the three corresponding electrodes. The gas sensor may be provided with two different types of leakage detectors to sense leakage of the gas-sensing agent from the sensor.

Abstract: A gas sensor, suitable for use under non-steady state conditions, has a gas-sensitive resistor with pairs of electrodes which either have different spacings between the electrodes of a pair, or comprise a pair at the active surface and further pairs buried in the resistor at different distances from the active surface. The sensor can be used in place of a sensor array, and is coupled to a processor for processing the resistance signals to detect and/or measure at least one target gas. The sensor is self-diagnostic, and factors such as relative humidity and ambient oxygen, that can otherwise affect the readings, can be compensated for without the aid of additional sensors for that purpose.

Abstract: A gas sensor assembly having a first housing portion having a receptacle formed therein and a second housing portion in the form of a cover. A gas-sensing agent is disposed in the receptacle, and a working electrode, a counter electrode, and a reference electrode provided on a single electrode support sheet are disposed in fluid contact with the gas-sensing agent. The first housing portion is provided with three conductive housing portions which are in electrical contact with the three electrodes, and the cover maintains pressurized contact between the three conductive housing portions and the three corresponding electrodes. The gas sensor may be provided with two different types of leakage detectors to sense leakage of the gas-sensing agent from the sensor.

Abstract: A pH-measuring method and device for monitoring and then correcting for electrode drift is provided. The device includes a pH-measuring electrode and more than one reference electrode. During operation, the pH-measuring device is place in contact with a sample. The pH value measured at each electrode pair is due to the electrical potential difference between the pH electrode and the reference electrode. The maximum and minimum pH values are determined, and then the remaining pH values are averaged together to generate an overall average pH. The maximum and minimum pH values are subtracted from the average pH to generate a difference which is then compared to a user-defined drift level to determine if a particular electrode is deficient. The pH values from deficient electrodes are not considered when the overall pH of the sample is determined.

Abstract: Disclosed is a method and a sensing device capable of measuring a predetermined measurement gas component continuously and accurately with good response over a long period of time without being affected by a high oxygen concentration in a measurement gas. The measurement gas is introduced into a first processing zone. A first electrochemical pumping cell is used to lower a partial pressure of oxygen in an atmosphere thereof to a degree sufficient to control a partial pressure of oxygen in a subsequent second processing zone. The gas is introduced into the second processing zone. Oxygen in an atmosphere is pumped out by using a second electrochemical pumping cell so that the partial pressure of oxygen in the atmosphere is controlled to have a low value of partial pressure of oxygen which does not substantially affect measurement of an amount of the measurement gas component. The gas is introduced into a third processing zone.

Abstract: An electrochemical-enzymatic sensor for the determination of substances, in particular glucose, in body fluids, which possesses a good long-term stability, includes: a sensor electrode of electrocatalytically inactive carbon, a counterelectrode, a reference electrode, an enzyme-containing layer located before the sensor electrode, and a diaphragm of biocompatible, hydrophilic, oxygen-permeable material covering the enzyme layer toward the body fluid and retaining the enzyme.

Abstract: A versatile, selective and sensitive non-aqueous electrochemical amperometric gas sensing devices of great sensitivity are disclosed which operate in a redox voltage range from about -3 to about +2.5 V and exhibit long term stability over a wide temperature range.

Abstract: A gas sensor assembly having a first housing portion having a receptacle formed therein and a second housing portion in the form of a cover. A gas-sensing agent is disposed in the receptacle, and a working electrode, a counter electrode, and a reference electrode provided on a single electrode support sheet are disposed in fluid contact with the gas-sensing agent. The first housing portion is provided with three conductive housing portions which are in electrical contact with the three electrodes, and the cover maintains pressurized contact between the three conductive housing potions and the three corresponding electrodes. The gas sensor may be provided with two different types of leakage detectors to sense leakage of the gas-sensing agent from the sensor.

Abstract: Provided is a method and apparatus for detecting electroinactive ions, and electroinactive ions solvated by small molecules including water. The method and apparatus utilizes a microporous ion exchange material such as a zeolite containing initially an electroactive species contained within the pores. The method operates on the principle that when charged species present in solution can access the pores of the microporous material, an ion-exchange reaction will occur whereupon the electroactive species will exit the microporous material, being replaced by the charged species. The electroactive species, upon exiting the microporous material, undergoes electrochemical reduction or oxidation at an electrode having a sufficiently high potential applied thereto. The method and detector disclosed herein is size selective since for example zeolites with a pore size comparable to that of the solvated ion to be detected but smaller than other electrolyte components can be utilized.

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 invention is directed to an electrochemical measuring cell 1 for detecting different gas components. The electrochemical measuring cell includes several measuring electrodes (8, 12, 13), a common counter electrode 21 and a common reference electrode 20 in an aqueous electrolyte 3. The measuring electrodes each include a diffusion membrane (7, 11) and individual diaphragms (9, 14) limiting the inflow of gas to the individual measuring electrodes (8, 12). The diffusion membranes (7, 11) cover the measuring electrodes (8, 12, 13). The measuring cell 1 is so improved that the selectivity of the detection of different gas components is improved. An electrolyte barrier 19 is provided at least between one of the measuring electrodes 8 and the remaining measuring electrodes (12, 13). The electrolyte barrier 19 prevents lateral diffusion within the diffusion membrane (7, 11).

Abstract: A planar air-to-fuel (A/F) ratio sensor and a driving circuit therefor are provided.

Abstract: A sensor for the amperometric assay of cholesterol is provided which comprises a sensing electrode containing a first redox mediator and a reference electrode in simultaneous contact with a reagent strip containing a second redox mediator. The presence of the second redox mediator greatly amplifies the current flow produced by the presence of cholesterol and produces linear correlation of current flow with concentration over an extended range. The sensing electrode comprises a non-conductive support member having an electrically conductive layer containing the first redox mediator. The reference electrode is typically a Ag/AgCl electrode formed by coating an ink containing Ag/AgCl dispersed in a resin on a non-conductive base.

Abstract: An electrochemical, galvanic type, oxygen sensor including scavenging electrodes for continuously reacting any unreacted or partially reacted active gases, such as oxygen, to remove the active gases prior to being dissolved or have been dissolved in the electrolyte resulting in less than accurate output signals. The use of the scavenging electrodes permits the gas sensor to detect active gases in a gas mixture in sub-parts per billion level accurately and without the need for external sparging of the electrolyte with a pure inert gas. The liquid electrolyte may be stored in the a sol-gel medium formed in sensor container and holding the electrolyte in voids or pockets in the medium thereby rendering the oxygen sensor portable with the stored electrolyte and usable within a few minutes of operation.

Abstract: During voltammetric analysis of liquids, the indicator electrode must be frequently changed in order to prevent memory effects and resultant changes to basic conditions during measurement. In order to be able to change the indicator electrodes simply, a plurality of indicator electrodes are arranged on a common carrier. For accommodation of the liquid (2) to be analysed, a vessel (1) is provided and the carrier (5) is mounted to move in relation to this vessel (1) in such a way that one of the indicator electrodes (6) can be selectively brought into the area intended for the liquid. The reference electrode (8) necessary for the measurement is arranged in the vessel (1) and likewise connected with the measuring device (20). With that, changing of the selected electrode (6) ensues by moving the carrier (5) relative to said vessel (1).

Abstract: An electrochemical sensor for remote detection, particularly useful for metal contaminants and organic or other compounds. The sensor circumvents technical difficulties that previously prevented in-situ remote operations. The microelectrode, connected to a long communications cable, allows convenient measurements of the element or compound at timed and frequent intervals and instrument/sample distances of ten feet to more than 100 feet. The sensor is useful for both downhole groundwater monitoring and in-situ water (e.g., shipboard seawater) analysis.

Abstract: A multi-electrode biosensor for sensing a material present in a sample includes a substrate, a plurality of working electrodes formed on the substrate, a counter electrode formed on the substrate, and a reference electrode formed on the substrate.

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: Disclosed is a multi-functional voltammetric or amperometric sensor useful for sensing components of the exhaust stream of a combustion system. The disclosed sensor (110) includes a solid oxide ion-conductive electrolyte membrane (112) having two sides (114,116). On one side is a working electrode (120), preferably covered by a diffusion barrier (126) exposed to the exhaust stream. On the other side (116), preferably exposed to air, is a counter-electrode (122) and, optionally, an reference electrode (124). Meters are provided to measure a current flex between the working and counter-electrodes.

Abstract: A method of electrochemically patterning a surface comprises providing an electrolyte overlying the surface and an array of electrodes adjacent the surface and in contact with the electrolyte, and altering the potential of one or more electrodes of the array so as to deposit or remove or chemically modify a substance on the surface adjacent the electrode. Several such treatments can be performed in sequence, using different electrodes of the array. The method is particularly suitable for step-wise chemical synthesis e.g. of oligonucleotides or other oligomers tethered to the surface. Electrode arrays for use in the method are also claimed.

Abstract: The present invention relates to a novel method and apparatus for the amperometric determination of an analyte, and in particular, to an apparatus for amperometric analysis utilizing a novel disposable electroanalytical cell for the quantitative determination of biologically important compounds from body fluids.