Abstract: A sensor for detecting the presence of a particular chemical by determining the absolute frequency shift in the oscillating frequency of an antibody-coated oscillator. Specific antibodies deposited on a high Q crystal oscillator detect the change in frequency as chemical particulates become trapped by the antibodies and change the effective mass of the crystal. In one embodiment, two oscillating crystals are used, one that has been coated with the antibodies, and one that is uncoated. This permits detection of frequency differences between the oscillating frequencies of the two crystals, thus eliminating pressure, temperature, and humidity corrections that conventionally must be made. The sensor maintains a high specificity by using antibodies that are specifically related to the chemical to be detected, while achieving relatively good sensitivity by using high Q oscillators, such as quartz or sapphire, and eliminating drift problems due to temperature, pressure, and humidity.

Abstract: A new ligand binding assay is based upon measurements of relaxation rates of the solvent, which are obtained with a magnetic resonance (MR) spectrometer. It is termed a solvent mediated relaxation assay system (SMRAS). SMRAS is based on the observation that the enhancement of proton relaxation rates produced by a magnetic material can be modulated by the binding of various analytes to a magnetic material. Hence the relaxation rate of the solvent can be interpreted to give information on the concentration of an analyte.

Abstract: An improvement is provided to a method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject, of the type including administering to the subject as a contrast agent to enhance such MR image an effective amount of a colloid including superparamagnetic metal oxide particles dispersed in a physiologically acceptable carrier. In accordance with the improvement, the method includes preparing the colloid in a manner that provides a reduction in toxicity in comparison with that associated with administration of the colloid after terminal sterilization. The improvement may include sterilizing the colloid by filtration. In an additional embodiment, the colloid may be sterilized by filtration and preserved by lyophilization. The colloid may be lyophilized in the presence of a compatible excipient. The excipient utilized may include a dextran or a citrate anion. Other embodiments include related compositions and methods.

Abstract: Biosensors are provided employing a thin crystalline diyne surfactant polymeric electrically conducting layer to which may be bound members of specific binding pairs. Binding of an analyte or a reagent to the specific binding pair member layer may change the electrical, optical or structural properties of the layer for measurement of analyte. The change in the polymeric layer provides for a sensitive measurement.

Abstract: The present invention relates to contrast enhancing agents, conjugates thereof, pharmaceutical compositions thereof, and methods for diagnostic analysis, particularly NMR image analysis using these agents. The contrast enhancing agents are chelates of paramagnetic, ferromagnetic or diamagnetic metal ion(s) complexed with new lipophilic complexing acids related to polyaminopolycarboxylic acids.

Abstract: An electrochemical specific binding assay of a ligand (e.g., antigen, hapten or antibody) wherein at least one of the components is enzyme-labelled, and which includes the step of determining the extent to which the transfer of electrons between the enzyme substrate and an electrode, associated with the substrate reaction, is perturbed by complex formation or by displacement of any ligand complex relative to unbound enzyme-labelled component.The electron transfer is aided by electron-transfer mediators which can accept electrons from the enzyme and donate them to the electrode or vice versa (e.g. ferrocene) or by electron-transfer promoters which retain the enzyme in close proximity with the electrode without themselves taking up a formal charge.The electrochemical apparatus will typically comprise two or three electrodes, including one working electrode onto which components may advantageously be immobilized.

Abstract: The invention relates to a novel assay for the determination of entities having biological activity and to a device for carrying out such determinations. The assay is a very sensitive one and quantities in the picogram per milliliter range can be determined. The assay is based on chrono-coulometric measurements with sequential measurements of a plurality of samples being carried out with the aid of a multiplexer, in combination with a potentiostat, there being provided suitable electrodes and means for applying a predetermined voltage. One of the electrodes is advantageously a glassy carbon electrode, carbon felt or cloth or carbon paper. Amongst biologically active entities there are antibodies/antigens; hormones/receptors; nuclotides/nucleotide probes, one of the members of such a pair being immobilized on an electrode surface, being tagged with an enzyme providing a signal in coulometric measurements.

Abstract: Electrophoretic resolving gel compositions, discontinuous stacking gel systems containing these and other resolving gel compositions, and kits for preparing such gel systems, comprising one or more polysaccharide hydrogels of which agarose is typical wherein at least one of the gels in the resolving gel composition has been derivatized and at least one of the gels in the resolving gel composition has been depolymerized sufficiently to reduce its casting-effective viscosity.

Abstract: Novel magnetic resonance imaging agents comprise complexes of paramagnetic ions with hydrazide derivatives of polyaminocarboxylic acid chelating agents. These novel imaging agents are characterized by excellent NMR image-contrasting properties and by high solubilities in physiological solutions. A novel method of performing an NMR diagnostic procedure involves administering to a warm-blooded animal an effective amount of a complex as described above and then exposing the warm-blooded animal to an NMR imaging procedure, thereby imaging at least a portion of the body of the warm-blooded animal.

Abstract: A method is disclosed for detecting the occurrence of a binding or complex-forming reaction between specific substances by utilizing the binding reaction to modify an electrical circuit, and then measuring a change in the electrical state of the circuit. A diagnostic element useful in such a method includes a layer of a biogenic substance, such as an antigen, coated onto a non-conductive base between a pair of electrical conductors superposed on the base. Antibodies which react with the antigen are treated so that they become bound to fine electrically conductive, metallic particles. The electrically conductive particles having antibody bound thereto are then added to the antigen layer deposited on the base and allowed to react therewith. Electrically conductive particles are thereby bound to the base due to the binding reaction between the antigen and antibody to thereby form aggregates of electrically conductive particles which modify the circuit.

Abstract: The invention relates to a piezoelectric biosensor device and also to a method and a system utilizing a piezoelectric biosensor device for detecting metabolic growth requirements, antibiotic responses, and the specific bacterial products of microorganisms. When a microorganism is grown in an appropriate nutrient medium containing a metabolic product responsive polymer, metabolic products of the organism acidify the medium and precipitate a polymer metabolic product complex which deposits or accumulates on the surface of a piezoelectric biosensor device. The mass change on the surface of the device resulting from this deposit produces a change in the resonant frequency of the piezoelectric biosensor device which can be used to determine the growth and type of microorganism.

Abstract: In order to produce a small-volume flow measuring cell with good flow characteristics in a sensor device for determining the concentration of a substrate in a sample medium, comprising an enzyme electrode which is covered by a membrane and a reference electrode, both of which are in contact with the measuring cell, the proposal is put forward that the reference electrode be located outside of the membrane cover of the enzyme electrode and that the maximum extension of the flow measuring cell normal to the flow direction of the sample medium essentially be the same as the diameter of the sensitive layer of the enzyme electrode.

Abstract: A method for removing or separating pathogenic or toxic agents from body fluids is provided. In substance, a fluid containing a preselected pathogenic or toxic agent is flowed into a mixing coil along with a plurality of paramagnetic beads. The paramagnetic beads include a coating which selectively binds the preselected pathogenic agent. By generating a magnetic field, the paramagnetic beads having the bound pathogenic agent are magnetically separated from the fluid. In one embodiment, the method includes the separation of HIV virus and/or HIV infected T-lymphocyte cells from blood. A continuous flow device for implementing the method of the present invention is also provided which includes in one embodiment a peristaltic pump which moves the subject liquid and paramagnetic beads through a mixing coil to promote contacting and binding of the paramagnetic bends to the pathogenenic agent.

Abstract: A biosensor of the invention comprises an insulating base board (1) having formed thereon, in sequence, leads (2, 3, 3'), an electrode system mainly made of carbon (4, 5, 5'), an insulating layer (6) and a reaction layer (14) composed of an enzyme and an electron acceptor, and being provided thereon with a space (8) defined by a spacer (7) and a cover 9). When a biological sample solution is brought into contact with the inlet (10) of the biosensor having the above-described structure, the sample solution is introduced into its inside, while the air within the space (8) is rapidly discharged through the outlet (11) and, at the same time, the space (8) is filled with the sample solution up to the neighborhood of the outlet. Thus, measurement can be conducted inexpensively at a high speed with a high accuracy through simple procedures without residual bubbles.

Abstract: An apparatus for correcting an initial measurement of the concentration of a first water soluble species dissolved in a water-based component of a biological fluid that also includes a second water soluble species and a volume occupying component, the initial measurement having been taken using an original sample of the fluid that had been diluted by an amount of additional aqueous solution to form a diluted sample is disclosed; the concentration of the second water soluble species is measured in an undiluted sample of the biological fluid to obtain a direct concentration and is measured using a diluted sample of the fluid to obtain an indirect concentration, and the initial measurement of concentration of the first species is adjusted based on a combination of the direct and indirect concentration determination of the second species.

Abstract: Structural and functional imaging of the pancreas can be achieved with magnetic resonance imaging and a secretin solution. An amount of secretin is placed in solution and administered to a patient for the purpose of pancreatic imaging. Because the secretin solution changes the signal intensity of the pancreas, it can be imaged relative to baseline fasting studies for the purposes of tumor detection and qualification of exocrine dysfunction.

Abstract: Complexes of a highly paramagnetic polyvalent metal, e.g., a lanthanide such as gadolinium, or of a less paramagnetic metal, e.g., iron, manganese, copper, cobalt, chromium or nickel, with a bisalkylamide of diethylenetriaminepentaacetic acid of the formula: ##STR1## wherein three groups M are hydroxyl groups and the remaining two groups M are NHR groups in which each group R is an alkyl group of the formula --(CH.sub.2).sub.n CH.sub.3 where n is zero or an integer of from 1 to 17, are disclosed. These complexes are useful as magnetic resonance imaging contrast enhancers.

Abstract: A method for identifying and/or determining the location of a tumor which produces or is associated with a cytoplasmic, intra-cellular or cell surface marker substance, is disclosed, which comprises the steps of:(a) injecting a human or animal subject with tumor specific antibody or a fragment thereof specific for the marker and labelled with a radioactive isotope of an element or a paramagnetic conjugate; and an irrelevant (non-tumor reactive) antibody which has been labelled with a non-radioactive isotope of the same or other element, or a non-paramagnetic conjugate; and(b) after a period of time sufficient for selective binding of the labelled tumor specific antibody to the tumor scanning the human or animal subject with a detector to locate the site or sites of uptake of labelled antibody or fragments thereof.Imaging compositions are also described.

Abstract: Paramagnetic chelates, as for example, Gadolinium diethylenetriaminepentaacetic acid (DTPA), manganese, ethylenediaminetetraacetic acid (EDTA), and others used as magnetic resonance imaging contrast agents are more toxic acutely when injected in high concentration or at rapid rates. The use of effective amounts of calcium in the form of, calcium chloride, calcium gluconate, or balanced salt solutions substantially reduces this toxicity without the need to add additional ligand.

Abstract: Nuclear magnetic resonance (NMR) imaging of body organs and tissues is enhanced by administering to a living animal body a substantially nontoxic paramagnetic image altering agent comprised of a composition containing a chelate of a paramagnetic element, such as manganese, gadolinium or iron, carried by a liposome. The chelate is carried by or within the external surface of the liposome in such a manner that after arrival at or delivery to the desired organ or tissue site, the paramagnetic image altering agent is released in a diagnostically useful fashion.

Abstract: A method of assaying a ligand in a sample which method includes the steps of contacting the sample with components comprising(a) a specific binding partner to the ligand and, if desired,(b) at least one reagent selected from ligand analogues and specific binding, partners,at least one of the said components (a) and (b) being labelled with an electron-donor or electron-acceptor,and determining whether (and, if desired, the extent to which) transfer of electrons between the said electron-donor or electron-acceptor label and a suitable charge-transfer partner resulting in charge-transfer complex formation is perturbed by ligand complex formation and/or by controlled external influences.

Abstract: A mearsuring instrument is disclosed having a reversibly selective binding protein immobilized upon the insulated-gate region of a field-effect transistor located on a sensor. With the sensor immersed in solution, the protein binds a select component of the solution to the gate producing an effect on a current flowing through the IGFET. A plurality of such binding protein-IGFET arrangements can be provided on the same sensor, including the same binding proteins having different binding coefficients K.sub.D or an array of proteins with different ligand specificity and/or affinity. Analysis of the IGFET's response to binding by a microprocessor allows, for example, the concentration of the component in solution to be determined. With a plurality of different binding proteins employed, the concentration of different components can be determined. Similarly, with binding proteins employed having different binding coefficients K.sub.

Abstract: A unitary multiple electrode sensor for detecting analytes in test samples and devices for using them. The unitary multiple electrode sensor includes a sensor support member and at least one electrode array being deposited on the sensor support member, the electrode array having sensor-activating chemical(s) attached to an embodient thereof. A test sample is applied to the electrode array to begin the test; and a sensor apparatus measures the test reaction which is occurring on the electrode array.

Abstract: An improved method for diagnosing and characterizing brain lesions is described which first involves chemically modifying the blood-brain barrier (BBB) in order to increase BBB permeability. Thereafter, a chemical agent (e.g. monoclonal antibody) is introduced which binds directly, specifically and exclusively to brain lesons. The chemical has a label attached thereto (e.g. gadolinium-DTPA). The chemical agent and label localize in regions of brain lesion proliferation. Thereafter, the brain is quantitatively analyzed to determine the amount of labeling agent present, preferably using magnetic resonance imaging techniques. This procedure enables the accurate analysis of brain lesions, and represents an advance in the art of diagnostic imaging.

Abstract: A method for immunoassay for an antigen involves the following steps: reacting a sample possibly containing an antigen to be determined, a definite amount of a conjugate of the antigen and a charged substance and a definite amount of labeled antibody specific for antigen; allowing the reaction products to electrophoretically migrate towards a carrier bearing an attached antibody specific for the charged substance, so that when the reaction products contact the carrier any reaction product of labeled antibody and antigen passes through the carrier and any reaction product of the labeled antibody and conjugate binds to the carrier attached antibody specific for the charged substance; determining the amount of labeled antibody thereby bound to the carrier and relating the determined amount of labeled antibody to the amount of antigen in the sample.

Abstract: A method for diagnosing HSV infections in human or non-human patients which involves intravenously administering to the patient a non-invasively assayable ligand-labelled anti-viral drug, wherein the drug is a compound which is phosphorylated bby the HSV-induced thymadine kinase present in HSV-infected cells to a phosphorylated assayable ligand-labelled compound which cannot diffuse from within the infected cells and then non-invasively assasying the presence or absence of the accumulated phosphorylated compound present therein.A pharmaceutical composition in intravenously administrable form and adapted for the diagnosis of HSV infection which is a mixture of a non-invasively assayable ligand-labelled anti-viral drug and a pharmaceutically acceptable carrier therefor.

Abstract: Several types of new microelectronic devices including diodes, transistors, sensors, surface energy storage elements, and light-emitting devices are disclosed. The properties of these devices can be controlled by molecular-level changes in electroactive polymer components. These polymer components are formed from electrochemically polymerizable material whose physical properties change in response to chemical changes, and can be used to bring about an electrical connection between two or more closely spaced microelectrodes. Examples of such materials include polypyrrole, polyaniline, and polythiophene, which respond to changes in redox potential. Each electrode can be individually addressed and characterized electrochemically by controlling the amount and chemical composition of the functionalizing polymer. Sensitivity of the devices may be increased by decreasing separations between electrodes as well as altering the chemical environment of the electrode-confined polymer.

Abstract: Agents useful for influencing the relaxation times in NMR diagnostics, contain at least one paramagnetic, physiologically compatible complex salt comprising a chelate from an open-chain or cyclic complex-forming compound containing organic nitrogen, phosphorus, oxygen and/or sulfur, and a complexed ion of the lanthanide elements of atomic number 57-70 or of the transition metals of atomic numbers 21-29, 42 and 44, and, optionally, an inorganic or organic base or acid, wherein said chelate complex is bound to a biomolecule.

Abstract: An electrical biosensor for analyte determination is prepared by polymerization of a mixture of a biological receptor capable of binding an analyte in a sample, a protein and a polymerizing agent such as glutaraldehyde to form a polymeric film on a transducer. The mixture preferably contains a stabilizer selected from lipids, detergents and antioxidents. The receptor may be an acetylcholine receptor and the analyte, acetylcholine. A preferred stabilizer is a combination of phosphatidyl choline and octyphenoxypolyethoxyethanol. In carrying out a determination, analyte in a sample binds to the receptor causing a change in an electrical characteristic of the film which is indicative of the presence of the analyte. The biosensor may contain a second polymeric film that is free of the receptor and which serves as a control.

Abstract: A method and an apparatus for detecting antigen-antibody reaction are disclosed in which a predetermined antigen or antibody is made to attach to the surface of an oscillator and the oscillator is immersed in the specimen blood so as to cause antigen-antibody reaction on the surface thereof. The oscillator is then made to oscillate and the amount of antibody or antigen attaching to the surface of the oscillator is determined in accordance with the data concerning the oscillation of the oscillator.

Abstract: A quartz crystal microbalance assay in which the binding of analyte to a surface on or near a quartz crystal microbalance (QCM) is detected by a conjugate which comprises an enzyme capable of catalyzing the conversion of a substrate to a product capable of accummulating on or reacting with a surface of the QCM leading to a mass change and, hence, a change in resonant frequency.

Abstract: A liquid mixture is assayed for a biologically active component that undergoes a reduction or oxidation reaction within a specific voltage range by immobilizing at an electrically conductive surface, a binding partner for the component, exposing the surface to the component to permit complexing to occur, applying a voltage to the surface in a range which will cause the component to undergo an oxidation or reduction reaction, and measuring the resulting current as an indication of the presence of the component.

Abstract: There is disclosed a diagnostic agent containing a non-radioactive paramagnetic metal species which agent comprises a physiologically tolerable, water-soluble, hydroxyl group-containing macromolecular product to which is chemically bound said metal species, said product consisting essentially of at least one polymeric or polymerized carbohydrate or polymerized sugar alcohol or derivative thereof.

Abstract: A paramagnetic metal species-containing diagnostic agent is disclosed which comprises a non-radioactive paramagnetic metal species and, as a carrier therefor, a physiologically tolerable, water-insoluble, hydroxyl group-containing, particulate macromolecular product consisting essentially of at least one polymeric or polymerized carbohydrate or polymerized sugar alcohol or derivative thereof.

Abstract: A biosensor comprising a main body and a built-in sensing electrode provided therein, wherein said sensing electrode is provided with a sensing part to which a buffer solution can be constantly fed and said main body is provided with an inlet which is brought into direct contact with a specimen to thereby incorporate the molecule to be assayed from said specimen therethrough, said inlet being covered with a membrane through which the molecule to be assayed can permeate. This biosensor enables a specified molecule contained in a specimen to be rapidly and conveniently assayed without requiring any pretreatment of the specimen.

Abstract: In its broadest aspect, the present invention provides a method of effecting an electrochemical specific-binding assay of a ligand, either qualitatively or quantitatively, in an apparatus comprising at leasts one electrode, in which method a labelled component of the assay medium is, at least in part, magnetically held in the vicinity of the electrode. The electrochemical assay method may include a separation step, whereby bound label may be separated from free label in the assay medium. Preferably the electrochemical assay method will include the step of determining a perturbation in an electrochemical characteristic of components of the assay medium associated with a ligand complexing reaction.Such an assay method is applicable to, for example, antibodies and antigens and suitable labels include redox centers, enzyme labels in the presence of an electron-transfer mediator and electron-transfer mediator labels in the presence of an electron donor or acceptor.

Abstract: The present invention provides a stabilized potassium ion-selective membrane comprising lysine-substituted valinomycin covalently bound to a polymeric substrate. The membrane of the invention exhibits improved stability and is used either on ISEs or on solid-state coated wire or semiconductor devices.

Abstract: A unitary multiple electrode sensor for detecting analytes in blood or blood component samples and devices for using them. The unitary multiple electrode sensor includes a sensor support member and at least one electrode array being deposited on the sensor support member, the electrode array having sensor-activating chemical(s) attached to an embodiment thereof. A test sample is applied to the electrode array to begin the test; and a sensor apparatus measures the test reaction which is occurring on the electrode array.

Abstract: Agents useful for influencing the relaxation times in NMR diagnostics, contain at least one paramagnetic, physiologically compatible complex salt comprising a chelate from an open-chain or cyclic complex-forming compound containing organic nitrogen, phosphorus, oxygen and/or sulfur, and a complexed ion of the lanthanide elements of atomic number 57-70 or of the transition metals of atomic numbers 21-29, 42 and 44, and, optionally, an inorganic or organic base or acid.

Abstract: A ligand in a sample can be assayed using electrochemical apparatus containing a working electrode and components comprising:(a) the sample,(b) a specific binding partner to the ligand, or a specific binding partner to the ligand and selected from ligand analogues and specific binding partners, and(c) an electron-source or electron-acceptor; at least one of components (b) being labelled with an electron-transfer mediator capable of aiding the transfer of electrons between the electron-source or electron-acceptor and the working electrode by accepting electrons from the electron-source and donating them to the working electrode, or accepting the electrons from the electrode and donating them to the electron-acceptor.

Abstract: Enzyme or substrate determinations can be achieved by employing an organic second substrate, which produces a product which may be coupled with a metal inorganic redox couple capable of interacting with and affecting the potential of a metal electrode on a semiconductor surface. Particularly, hydrogen peroxide or indoxyl phosphate are coupled with iron- or ruthenium-containing ionic redox couples for determination with a noble metal electrode.

Abstract: A capacitive chemical sensor is disclosed that uses an ion exchange layer to detect analyte ions in a liquid medium. An exchange mechanism occurs on the surface of the ion exchange layer, wherein a portion of the counter-ions are removed from the surface in favor of analyte ions. The resulting movement of counter-ions from the surface of the ion exchange layer alters the dielectric constant of the liquid medium along the surface of the ion exchange layer. This change in dielectric constant produces a change in capacitance of the capacitive chemical sensor.

Abstract: Test method and apparatus for determining the presence of, the concentration of, or the absence of, immunologically-active substances in liquid media by measuring any change of electrical impedance of an electrode due to the presence of, or the absence of, the reaction of a product of enzyme linked immunologically-active substance and a proper enzyme substrate.

Abstract: Mixed anionic complexes of the type (MW.sub.m Y.sub.n Z.sub.p).sup.r- wherein M is a paramagnetic ion; W, Y, and Z are each different ligands which chelate M; and m+n+p.gtoreq.2 but preferably less than 5, with the proviso that at least two different ligands W, Y, Z are present in the complex; are provided as versatile NMR contrast and shift reagents, especially for clinical diagnostic imaging and spectroscopic procedures. In an exemplary embodiment, at least one of the ligands W, Y, Z is metabolizable by the target tissue, and at least one of the ligands W, Y, Z is substantially inert; the complex is thus tailorable to improve both physiological tolerance and tissue specificity of NMR contrast and shift reagents, while maintaining excellent contrast and shift effects for reliable and accurate results.

Abstract: An immunoassay method and apparatus includes the vibration of beads within a cell, the beads having a complex of a substance conjugated with an enzyme as a marker on the surface thereof, and using an optical measurement device to quantatively determine the amount of the marker in the cell. The vibration is provided by including a magnetic material in the beads and causing a magnetic field to move within the cell. The vibrations have at least a component transverse to a measurement direction of the optical measurement device. The movement of the magnetic field in the cell is caused by the reciprocation of a bar having magnets thereon and in a position adjacent to the cell.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: In analysis, particularly for medical diagnostics, material can be selectively bound to the surface of a piezoelectric crystal by a reagent. The amount of material so bound affects the speed of propagation of an acoustic wave launched and received on the crystal surface by respective electrode pairs. Previously the crystal was used as a resonant element in an oscillator controlling the frequency of oscillation and so indicating the amount of bound material. However, the oscillator was either unstable or the range of bound masses too small to be of practical use. In the present invention delay between launch and reception of the acoustic wave provides a control signal for a voltage controlled oscillator. A much more stable system can therefore be constructed with a wide working range and high stability since the crystal is no longer the resonant element. Much greater sensitivity is also possible since the oscillator frequency may be greatly increased.

Abstract: Several types of new microelectronic devices including diodes, transistors, sensors, surface energy storage elements, and light-emitting devices are disclosed. The properties of these devices can be controlled by molecular-level changes in electroactive polymer components. These polymer components are formed from electrochemically polymerizable material whose physical properties change in response to chemical changes, and can be used to being about an electrical connection between two or more closely spaced microelectrodes. Examples of such materials include polypyrrole, polyaniline, and polythiophene, which respond to changes in redox potential. Each electrode can be individually addressed and characterized electrochemically by controlling the amount and chemical composition of the functionalizing polymer. Sensitivity of the devices may be increased by decreasing separations between electrodes as well as altering the chemical environment of the electrode-confined polymer.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: The present invention relates to a process for indicating toxic substances in air that is supplied to accommodation used for personnel, preferably the cab of a motor vehicle, this having error compensation for humidity and temperature in one or a plurality of semiconductor gas sensors that are used, in which connection the sensor heating voltage is controlled to provide constant heating output and the sensor temperature pick up as well as the necessary amplifier (control stage) used to generate the temperature-varied heating voltage are arranged in a common housing, and that in the area of the sensors this housing is perforated.