Abstract: Methods and systems for simultaneously measuring concentration of two or more different cations in solution. The methods include the steps of applying a steady state polarization technique to a solution comprising two or more different cations; measuring the limiting currents of the solution; and correlating the limiting currents with the concentration of the different cations. The system includes a working electrode; a potentiostat; a counter electrode; a reference electrode; a solution comprising different cations to be analyzed; and a model for correlating the limiting currents with the concentration of the pair cations. The working electrode may be any electrode compatible with the media, including noble metals, carbon, or combinations thereof. In some embodiments, the working electrode is a rotating disk electrode (RDE).

Abstract: This invention provides a reference electrode that can be downsized and stable in voltage. The reference electrode in accordance with this invention is a reference electrode that does not require an internal aqueous solution such as a KCl aqueous solution and comprises a metal body, a slightly soluble salt film that comprises a slightly soluble salt of the metal body and that coats the metal body and a hydrophobic ionic liquid that is arranged to make contact with both the slightly soluble salt film and a sample to be measured.

Abstract: A reference half-cell for application in an electrochemical sensor, comprising a housing, in which a chamber containing a reference electrolyte is formed, wherein the reference electrolyte (5, 105) is in contact with a medium surrounding the housing via a liquid junction arranged in a wall of the housing, wherein the liquid junction comprises a porous diaphragm, especially a porous ceramic diaphragm, and wherein the diaphragm has, at least partially, a coating, which comprises at least one metal.

Abstract: The present invention relates to a device for sensing a target chemical. The device includes a flexible, non-planar substrate; a printed, solid-state sensing element comprising a chemical sensing material which produces an electrical signal upon interaction with the target chemical; a first printed electrode comprising a first conductive composition; and a second electrode comprising a second conductive composition. The first and second electrodes are electrically isolated from one another, and one or both of the first and second electrodes is in electrical contact with said sensing element. The first and second electrodes and the sensing element collectively form an electrochemical sensor which is coupled to the flexible, non-planar substrate. Medical devices comprising the device of the present invention and methods of making a device for sensing a target chemical are also disclosed.

Abstract: An ion sensor includes a sensor main body having a channel for a sample and an opening connected to the channel, a responsive portion which is filled in the opening and selectively responds to a specific ion, an electrode which has a ring shape, is set such that a central axis of the ring is substantially perpendicular to a central axis of the channel, and senses the response, and an output terminal which is formed out of one metal plate out of which the electrode is formed, has a pin shape, and is held by the sensor main body such that an axis extends along a direction substantially perpendicular to the central axis of the channel and the central axis of the ring.

Abstract: A sensor for registering a measurement variable of a medium, comprising a sensing body with a section of surface area, which is exposed to the medium to register the measurement variable, whereby a condition of the section of surface area affects the provided value of the measured measurement variable, whereby the section of surface area comprises a coating that comprises nanoparticles. The coating, which comprises the nanoparticles, comprises at least one nano polymer.

Abstract: Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in hydrogen ion concentration (pH), changes in other analyte concentration, and/or binding events associated with chemical processes relating to DNA synthesis.

Abstract: An ion sensor includes: a conductive base structure including a substrate and an electrode film formed on the substrate; a plurality of ion-sensitive nanorods protruding from the electrode film; and an encapsulant enclosing the conductive base structure, surrounding the ion-sensitive nanorods, and formed with a window for exposing the ion-sensitive nanorods. Each of the ion-sensitive nanorods has a conductive core and an ion-sensitive layer formed on and enclosing the conductive core. The ion-sensitive material exhibits an ion selectivity of absorbing an ion of interest thereon for inducing a surface potential corresponding to concentration of the ion of interest.

Abstract: An analyte concentration, in a sample fluid, is determined by differential measurement. Two or more capacitive field effect sensors have an identical basic structure and are arranged in a shared measuring cell. One of the sensors forms a measuring sensor with an active transductor layer. Another sensor forms a reference sensor without an active transductor layer. The sensors are contacted with the sample fluid and the sensors, have an associated reference electrode, or have a shared reference electrode. A bias voltage composed of an electric DC voltage and a superimposed AC voltage is applied between each sensor and associated reference electrode(s) Capacitance changes due to the analyte are eliminated by controlling the bias voltage applied to the measuring sensor in a closed control loop. A measuring signal is obtained by calculating a difference between voltage values representative of DC voltage potentials applied to the measuring sensor and reference sensor, respectively.

Abstract: An ion sensing circuit includes an ion sensing element configured for exposure to an electrolytic solution and control of a sensing current through the ion sensing element according to an ion concentration of the electrolytic solution. The ion sensing circuit further includes a current-to-voltage converter coupled electrically to the ion sensing element for generating a converted voltage from the sensing current. The ion sensing circuit also includes a comparator coupled electrically to the current-to-voltage converter for comparing the converted voltage and a threshold voltage to form a comparison result. In addition, the ion sensing circuit includes a latch coupled electrically to the comparator and the current-to-voltage converter. The latch is configured for sampling the output of the comparator according to a clock signal to generate a digital signal used by the current-to-voltage converter for converting the sensing current to the converted voltage.

Abstract: A water quality analyzer comprises: sensor electrodes 1a, 1b made of different metals from each other, the electrodes in a liquid of inspecting object generating a sense voltage in proportion to the liquid's impurities concentration; an operational amplifier OP1 amplifying the sense voltage without inverting to provide for a CPU 3; a resistor R0 whose one end is connected to the electrode 1a; and a voltage divider 2 applying a voltage obtained by dividing the sense voltage by a prescribed division ratio to R0's another end. The CPU 3 calculates input signal from OP1 to obtain chlorine concentration and displays the calculated result on a LCD 4 in a measurement mode, and sets the division ratio of the divider 2 so that sense voltage across electrodes 1a, 1b soaked in a liquid including prescribed concentration chloride approximately agrees with a reference voltage of prescribed concentration in a sense-voltage calibration mode.

Abstract: Potentiometric sensor comprising an ion selective electrode and the latter, on its part, containing a membrane characterized in that it comprises: a thermoplastic material; an electroactive substance based on a salt wherein the cation is the protonated form of the analyte to be determined and the anion is a cluster which comprises boron atoms; and a plasticizing agent. In addition, the invention further relates to the use of said sensor for the detection and/or quantification of a compound containing at least one nitrogen atom.

Abstract: A gas sensor (100) in a sensor housing (1) has a gas-permeable membrane (7) for the inlet of a gas sample to be analyzed to a measuring electrode (6). The gas sensor (100) is provided with a test gas generator (18), which has a generator housing (8). The generator housing (8) is fastened in the area of the gas-permeable membrane (7) and has a central gas outlet opening (21) for the gas sample to pass into the sensor and has outlet openings (19) directed towards the gas-permeable membrane (7) for the test gas.

Abstract: A meter is adapted for measuring concentrations of a chemical in a flowing solution. The meter has a barrier that shields a sensor from the high turbulence of the solution flow. One or more membranes can be employed to selectively filter out various ions or other chemicals.

Abstract: The present invention provides systems, devices, apparatuses and methods for automated bioprocessing. Examples of protocols and bioprocessing procedures suitable for the present invention include but are not limited to: immunoprecipitation, chromatin immunoprecipitation, recombinant protein isolation, nucleic acid separation and isolation, protein labeling, separation and isolation, cell separation and isolation, food safety analysis and automatic bead based separation. In some embodiments, the invention provides automated systems, automated devices, automated cartridges and automated methods of western blot processing.

Abstract: The present invention aims to simplify the structure and a fabrication method of an ion-selective electrode in an ion concentration measuring device that measures an anion, particularly a chloride ion, in a biological component. To this end, in a potential difference measuring unit, a quaternary ammonium salt derivative serving as a ligand for an anion is immobilized to the surface of a gold electrode by using as a linker an insulative molecule forming a self-assembled monolayer. The potential difference measuring unit measures an electromotive force generated with anion binding, as an interface potential change on the surface of the gold electrode. In order to reduce the influence of adsorption of impurities on the electrode surface, a high-molecular weight polymer is physically adsorbed on the gold electrode and thus used when a biological component is measured.

Abstract: An ISFET detector for determining concentration of a target ion in a fluid, the apparatus comprising: a semiconducting substrate comprising a source and a drain having source and drain electrodes respectively and a channel region between them in the substrate; an insulating material overlying the channel region; a gate electrode formed on the insulating material; a reference electrode electrifiable to establish an electric field in the channel region; an accumulator comprising a layer of material of thickness less than or equal to about 2 nm (nanometers) that accumulates a quantity of target ions responsive to concentration of the target ions in the fluid; a layer of a conducting material on which the accumulator is formed that is separate from the gate electrode; and a conducting element that electrically connects the layer of conducting material to the gate electrode.

Abstract: An apparatus and method for detecting ionic materials includes a sensing electrode which contacts a liquid sample and detects a sensing voltage corresponding to a surface potential which is changed by a concentration of ionic materials in the liquid sample, a first switching transistor having a first terminal connected to the sensing electrode and a second terminal connected to a first node, a second switching transistor having a first terminal connected to a reset voltage and a second terminal connected to the first node, and a sensing transistor having a gate connected to the first node.

Abstract: Provided are a FET-based sensor for detecting an ionic material, an ionic material detecting device including the FET-based sensor, and a method of detecting an ionic material using the FET-based sensor. The FET-based sensor includes: a sensing chamber including a reference electrode and a plurality of sensing FETs; and a reference chamber including a reference electrode and a plurality of reference FETs. The method includes: flowing a first solution into and out of the sensing chamber and the reference chamber of the FET-based sensor; flowing a second solution expected to contain an ionic material into and out of the sensing chamber while continuously flowing the first solution into and out of the reference chamber; measuring a current in a channel region between the source and drain of each of the sensing and reference FETs; and correcting the current of the sensing FETs.

Abstract: Method for measuring the global ion concentration of a body fluid that comprises application of a stable DC voltage between first and second electrodes of a cell for measuring the global ion concentration of a body fluid so as to cause electrochemical hydrolysis reactions of the body fluid water to occur at the level of said first and second electrodes, measurement of a hydrolysis current generated by said electrochemical hydrolysis reactions of the water and determination of the global ion concentration of the body fluid by comparison with a previously defined calibration curve. The measuring cell comprises a fluid channel having an internal cross-section smaller than or equal to 1.5 mm.

Abstract: Methods and apparatus relating to FET arrays for monitoring chemical and/or biological reactions such as nucleic acid sequencing-by-synthesis reactions. Some methods provided herein relate to improving signal (and also signal to noise ratio) from released hydrogen ions during nucleic acid sequencing reactions.

Abstract: A method and apparatus measures the presence of total residual oxidant species in aqueous environments. More specifically, the apparatus is operable to measure hypohalites (e.g., hypochlorite and hypobromite) in water containing halide salts using electrochemistry. The apparatus can be a sensor having four electrodes—a reference electrode, a working electrode, and two auxiliary electrodes. The fourth electrode, i.e., the second auxiliary electrode, can be used to generate ionized water near and in contact with the working electrode. The ionized water can clean the working electrode to minimize effects due to scaling or biofilm formation. As such, the working electrode does not need the capability to clean itself. Thus, other elements, originally believed to be unsuitable for use in saline aqueous environments, can be used for the electrodes, for example, gold.

Abstract: In a gas sensor element, a measurement gas is introduced to a measurement electrode through a porous diffusion-resistant layer. A catalyst layer is formed on an outer surface of the diffusion-resistant layer via which the measurement gas flows into the diffusion-resistant layer. In the catalyst layer, the percentage content of Pt is in the range of 2.5 to 12 mass %, the percentage content of Pd is in the range of 0.4 to 2 mass %, and the percentage content of Rh is in the range of 0.06 to 1.5 mass %. The catalyst layer includes catalytic noble metal particles each of which is made of an alloy that contains at least Pt. For each of the catalytic noble metal particles, the percentage content of Pt at an outer peripheral portion of the catalytic noble metal particle is lower than that at a core portion of the catalytic noble metal particle.

Abstract: The present invention allows simple and sensitive detection of microimpurities, microdefects, and corrosion starting points which may be present in a material. A probe microscope has a function to sense ions diffused from a specimen in a liquid. A probe is caused to scan over a predetermined range on a specimen. Then, the probe is fixed to a particular position in a liquid so as to set the distance between the specimen and the probe to a given value at which the microstructure of the specimen surface cannot be observed. Thereafter, one of the current between the probe and a counter electrode and the potential between the probe and a reference electrode is controlled, and the other of the current and potential which varies in accordance with the control is measured. Thus, ions diffused from the specimen are sensed.

Abstract: A crown ether derivative that acts as cation capturing ligand and alkanethiol having a longer carbon chain than a linker are immobilized, coexisting together, on the surface of a gold electrode, by using as the linker an insulating molecule (e.g., alkanethiol) that forms self-assembled monolayers. Electromotive force produced in association with cation coordination is measured by a potentiometer through a change in interfacial potential on the surface of the gold electrode. Further, an insulated gate field effect transistor formed on the same substrate as the gold electrode is used as the potentiometer. Furthermore, a straight-chain polymer physically adsorbed on the gold electrode is used in order to reduce the influence of the adsorption of impurities on the surface of the electrode during biological sample measurement.

Abstract: Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in hydrogen ion concentration (pH), changes in other analyte concentration, and/or binding events associated with chemical processes relating to DNA synthesis.

Abstract: An electrochemical gas sensor has a working electrode having a gas porous membrane and a catalyst layer formed on one side of the membrane; a counter electrode, electrolyte in contact with the catalyst both of the working electrode and of the counter electrode; and a support that is in contact with, and presses against the side of the working electrode remote from the electrolyte and that compresses the electrodes and the electrolyte together. The support includes open areas enabling gas to contact the membrane. The support provides a faster response and provides greater efficiency of catalyst usage.

Abstract: An amperometric sensor includes a first electrode, a second electrode and a reference electrode. The sensor further includes a switch to selectably electrically connect the first electrode as a working electrode and to electrically connecting the second electrode as an auxiliary electrode during a first time interval. During a second time interval, the switch electrically connects the first electrode as the auxiliary electrode and electrically connects the second electrode as the working electrode. The switching of the two electrodes is repeated continuously as amperometric measurements are performed. Preferably, the sensor includes an ultrasonic transducer proximate the working electrode and the auxiliary electrode to clean the electrodes.

Abstract: Electrolyte analyzers are used in a variety of ways, and problems vary from reagent deterioration due to reagent replenishment, mixing of foreign substances during reagent replenishment, electrode deterioration due to the passage of the validity date, to the operator's inputting errors. It is thus necessary to judge abnormalities of measured values resulting from such inappropriate usage, based on the fluctuation patterns of the results of daily electrolyte calibration. The fluctuation patterns of each measured item are extracted from the results of daily electrolyte calibration. The electromotive force balance ratio between the internal standard solution and high/low-concentration standard solutions is calculated as well as its fluctuation pattern. The obtained fluctuation patterns are compared against atypical fluctuation patterns stored in the electrolyte analyzer. When any of the extracted patterns matches any of the atypical patterns, the analyzer activates an alarm.

Abstract: A method is provided to sample a sensor array. The method can include measuring a waveform associated with a chemical event occurring on the sensor array. The waveform can include at least one region associated with expected measured values and at least one region associated with unpredictable measured values. The method can also include applying a first frame averaging to the at least one region associated with the expected measured values. Here, a first number of frames can be included in the first frame averaging. Further, the method can include applying a second frame averaging to the at least one region associated with the unpredictable measured values, where a second number of frames can be included in the second frame averaging. The second number of frames can be less than the first number of frames.

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

Abstract: Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in the concentration of inorganic pyrophosphate (PPi), hydrogen ions, and nucleotide triphosphates.

Abstract: A low-slope pH electrode (100) is provided according to an embodiment of the invention. The low-slope pH electrode (100) includes an electrode body (102), a pH-sensitive glass (122) fused into the electrode body (102), with the pH-sensitive glass (122) including a predetermined area, and a mask (124) formed over a predetermined portion of the predetermined area of the pH-sensitive glass (122) in order to form a low-slope pH characteristic. At least a portion of an ion exchange performed by the pH-sensitive glass (122) is blocked by the mask (124).

Abstract: Improvements in references electrodes, halogen sensors, pH sensors, TDS sensors, combinations thereof, and related methods.

Abstract: A system and method for voltammetric analysis of a liquid sample solution.

Abstract: The present invention pertains to a means of combining and configuring specific hydrophilic and dielectric materials in such a way as to allow an antimony/reference electrode pH sensor to be packaged and stored dry yet become fully hydrated to an activated state after exposure to aqueous liquids. The sensor is packaged and stored dry to maintain component stability and minimize component degradation. When the user removes the sensor from the package and the sensor tip is submerged in a hydration (ion conduction) media or solution, the hydrophilic coating along with the impregnated reference wick, absorb the fluid to create an electrolytic gel inside the reference wick, which activates the pH sensor.

Abstract: Disclosed is a sensitive glass for use in a pH-sensitive glass electrode, which comprises at least Me2O3 (Me represents a lanthanoid) and further comprises Y2O3 or Sc2O3 in an amount smaller than that of the Me2O3. Also disclosed is a sensitive glass for use in a cation-sensitive glass electrode, which comprises at least Y2O3 or Sc2O3.

Abstract: The present invention relates to a method for passivating a semiconductor component having at least one chemosensitive electrode that is blinded by the application of a glass layer. The present invention also relates to a device for detecting at least one substance included in a fluid stream, including at least one semiconductor component acting as a measuring sensor as well as at least one semiconductor component acting as a reference element, the semiconductor components each having a chemosensitive electrode, and the chemosensitive electrode of the semiconductor component acting as the reference element being passivated. For the passivation, a glass layer may be applied at least to the chemosensitive electrode of the semiconductor component acting as reference element.

Abstract: Embodiments of the invention provide amperometric analyte sensors having optimized elements such as electrodes formed from sputtered platinum compositions as well as layers of material selected to optimize the characteristics of a wide variety of sensor elements and sensors. While embodiments of the innovation can be used in a variety of contexts, typical embodiments of the invention include glucose sensors used in the management of diabetes.

Abstract: A surface-contact sensor includes a housing defining an opening, an ion-permeable membrane at the opening, a counterelectrode within the housing, and a reference electrode within the housing that is spaced apart from the current-collector. A current-collector pad includes a grommet support having a base and a lumen defining an opening. An ion-permeable membrane spans at least a portion of the opening of the grommet. The ion-permeable membrane is held in place by a gasket surrounding the lumen. A current collector, at least in one embodiment, is proximate to a portion of the ion-permeable membrane that spans the opening.

Abstract: Ion concentration measurement requires a calibration before the start of the measurement, and thus the start of the measurement is delayed for the calibration period. Hence, an ion selective electrode cartridge including an ion selective electrode for measuring the concentration of particular ions dissolved in a test solution is provided with a storage means storing therein an electrode slope value specific to the ion selective electrode.

Abstract: A wet flow-type ion selective electrode device requires not only a large amount of test solution but also cumbersome management works such as flow path cleaning and device conditioning. Provided is an ion selective electrode cartridge which includes at least one ion selective electrode forming an electrical path with a reference electrode when a test solution is infused, and in which the ion selective electrode and the reference electrode is arranged to surround a container.

Abstract: A method of observing reaction intermediaries during a chemical reaction and comprising detecting an electrical signal output from an ion sensitive field effect transistor exposed to said reaction, and monitoring the detected electrical signal to discriminate discrete fluctuations in the electrical signal, the discrete fluctuations indicating reaction intermediaries occurring during a chemical reaction.

Abstract: A device for the purification of water, has the following components: (a) a storage tank (10) for retention of the purified water; (b) a feed pipe (15), leading from the water to be purified to the storage tank (10); (c) a reactor (4) for anodic oxidation of the water arranged within the feed pipe (15); (d) the storage tank (10) having a redox sensor (5) for measuring the redox potential; and (e) water supply from the feed pipe (15) into the storage tank (10) is performed discontinuously.

Abstract: An electrode for use in a electrochemical sensor comprises carbon modified with a chemically sensitive redox-active compound, excluding an electrode based on carbon having derivatised thereron two redox-active species wherein at least one of said species is selected from anthraquinone, phenanthrenequinone and N,N?-diphenyl-p-phenylenediamine (DPPD). The invention further provides a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material; and a counter electrode, wherein the ratio of the surface area of the working electrode to the surface area of the counter electrode is from 1:10 to 10:1. Also provided is a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material, and a counter electrode, wherein the area of the working electrode is from 500 ?m2 to 0.1 m2. The uses of these electrodes and sensors are also described.

Abstract: The invention relates to an apparatus and to a method for detecting and/or quantifying mercuric ions, Hg2+. The apparatus of the invention is of the type comprising an electrical device comprising two electrodes and a substrate comprising at least one surface made of an organic or inorganic semiconductor material, the electrodes being in electrical contact with said organic or inorganic semiconductor material, and a device for measuring the variation in the conduction current between the two electrodes, and wherein at least one compound which complexes mercuric ions Hg2+, selected from a dithia-dioxa-monoaza crown ether compound, an N,N-di(hydroxyethyl)amine, an N,N-di(carboxyethyl)amine, and mixtures of two at least of these compounds, is bonded to said semiconductor material or to an electrode of said electrical device. The invention finds application in the field of the detection of mercuric ions, in particular.

Abstract: The invention relates to a device for measuring at least one physico-chemical parameter of water, said device including a means for measuring the concentration of active chlorine in the form of hypochlorous acid HOC1 in said water. According to the invention, said means for measuring the chlorine concentration in the form of hypochlorous acid HOC1 includes first (21) and second (22) amperometric sensors for detecting chlorine in the form of hypochlorous acid HOC1, each outputting a signal, said two amperometric chlorine sensors (21, 22) having a single common reference electrode (25) and being connected to a double potentiostat, characterised in that said invention includes a means for simultaneously implementing said first (21) and second (22) amperometric sensors, and in that said invention includes a means for measuring a difference between the signals output by said two sensors (21, 22).

Abstract: Disclosed are a pH or concentration measuring device and a pH or concentration measuring method which enable measurement in the shortest possible time even in an object to be measured having low buffer capacity.

Abstract: An electrode for superoxide anions which contains a conductive component and, superimposed on a surface thereof, a film resulting from electrolytic polymerization of a metal thiofurylporphyrin/axial ligand complex; and a sensor for measuring a superoxide anion concentration including the same. The electrode for superoxide anions can prevent poisoning by a catalyst poison such as hydrogen peroxide. Accordingly, in any of in vitro or in vivo environments, this electrode for superoxide anions enables detection of superoxide anion radicals without suffering any influence from a catalyst poison such as hydrogen peroxide. Moreover, quantitative assay of superoxide anions can be performed with this electrode for superoxide anion in combination with a counter electrode or a reference electrode. Thus, this electrode for superoxide anions can find wide applicability in various fields.

Abstract: Described herein are substrates, sensors and systems related to measuring the concentration of an analyte such as hydrogen ion in a sample. Redox active moieties whose reduction and/or oxidation potentials are sensitive to the presence of an analyte are immobilized onto a silicon surface. Immobilized redox active moieties whose reduction and/or oxidation potential are insensitive to the analyte can be used for reference. Voltammetric measurements made using such modified silicon surfaces can accurately determine the presence and/or concentrations of analytes in a sample of interest. The silicon electrochemical sensors of the invention are robust and can be made so as not to require calibration or re-calibration.