Abstract: Chemical sensors for detecting the activity of a molecule or analyte of interest is provided. The chemical sensors comprise and array or plurality of sensors that are capable of interacting with a molecule of interest, wherein the interaction provides a response fingerprint. The fingerprint can be associated with a library of similar molecules of interest to determine the molecule's activity and diffusion coefficient.

Abstract: Methods and apparatus are provided for measuring contaminant mobile ions in a dielectric portion of a semiconductor. The apparatus is comprised of a heat source configured to elevate a temperature of the dielectric portion of the semiconductor and mobilize the contaminant mobile ions. The apparatus is also comprised of a fluid source configured to expose the dielectric portion of the semiconductor to a mobilizing fluid having contaminant ion releasing atoms that assists in mobilizing the contaminant mobile ions. The apparatus further comprises a mobile ion measurement unit configured to perform measurements of the contaminant mobile ions in the dielectric portion of the semiconductor.

Abstract: A sensor (700) for detecting analytes of interest in which natural or synthetic macromolecules (740) are immobilized on an electrically conductive base member (720) to insure that interaction of analyte with the macromolecules will lead to altered de novo electrical signals in a sensor circuit (720,770,198).

Abstract: In a test strip measuring system, such as for measuring the concentration of certain substances in body fluids, the system consists of a test strip onto which the fluid to be investigated is applied, and a measuring device into which the test strip is inserted for making the desired measurements. The system further includes a code carrier with a memory storing information concerning the manufacturing of the test strip and/or the measurement to be carried out in using the test strip. Still further, the system includes an adapter through which the code carrier is connectable with a data processing unit for the measuring device. On one hand, the adapter allows one and the same code carrier to be used with different measuring device and on the other hand allows different code carriers to be used with one and the same measuring devices.

Abstract: The present invention includes free-standing, shaped ceramic-bearing bodies useful in fluid sensors, filters, and catalyst devices. The invention also includes methods and processes for using such devices. In a preferred embodiment of the invention, shaped metallic foils are converted into free-standing, porous rutile foils having an open pore structure by oxidation at an elevated temperature. The exposure of such foils to increasing concentrations of reducing gases such as carbon monoxide results in an increase in the steady-state electrical resistance. The resultant ceramic-bearing bodies may be used as effective sensors of reducing gas species in such applications as automobile and industrial emissions.

Abstract: Luminescence test measurements are conducted using an assay module having integrated electrodes with a reader apparatus adapted to receive assay modules, induce luminescence, preferably electrode induced luminescence, in the wells or assay regions of the assay modules and measure the induced luminescence.

Abstract: The present invention includes free-standing, shaped ceramic-bearing bodies useful in fluid sensors, filters, and catalyst devices. The invention also includes methods and processes for using such devices. In a preferred embodiment of the invention, shaped metallic foils are converted into free-standing, porous rutile foils having an open pore structure by oxidation at an elevated temperature. The exposure of such foils to increasing concentrations of reducing gases such as carbon monoxide results in an increase in the steady-state electrical resistance. The resultant ceramic-bearing bodies may be used as effective sensors of reducing gas species in such applications as automobile and industrial emissions.

Abstract: Disclosed herein is a method and apparatus for analyzing, sensing and measuring information related to the concentrations of various gases, including NOx, hydrocarbons, carbon monoxide and oxygen, in a multi-component gas system using chemical sensors and chemical sensor arrays. The sensors and sensor arrays use chemo/electro-active materials to analyze and detect the presence of gases.

Abstract: A diamond electrode comprises a polycrystalline mass of diamond particles bonded together and has a porous surface, or an at least partly porous surface. The porous surface of the electrode is typically created by leaching non-diamond material, such as a second phase of a metallic material, at least in part, from the bonded polycrystalline mass of diamond particles, either before or after shaping it into an electrode. Alternatively, or additionally, the porous surface of the electrode may be created by subjecting a mass of diamond particles to conditions of elevated temperature and pressure to self-bond the particles together in the absence of a second phase.

Abstract: A catalyst deterioration detecting device of the invention has exhaust emission purifying catalyst on an exhaust passage of an internal combustion engine and air-fuel ratio sensors provided upstream and downstream of the exhaust emission purifying catalyst, respectively, and detects the deterioration of the exhaust emission purifying catalyst based on the outputs of the air-fuel ratio sensors. An index characteristic value of catalyst deterioration is calculated from the outputs of the air-fuel ratio sensors, a time-lapse changing ratio of the calculated index characteristic value of catalyst deterioration is calculated, and the deterioration of the exhaust emission purifying catalyst is determined based on the calculated time-lapse changing ratio.

Abstract: Materials and methods are provided for producing patterned multi-array, multi-specific surfaces for use in diagnostics. The invention provides for electrochemiluminescence methods for detecting or measuring an analyte of interest. It also provides for novel electrodes for ECL assays. Materials and methods are provided for the chemical and/or physical control of conducting domains and reagent deposition for use multiply specific testing procedures.

Abstract: A method and apparatus for sensing a flammable vapor are described herein. Initially, a first thermal conductivity of a vapor at a first temperature and a second thermal conductivity of the vapor at a second temperature can be determined. Thereafter, a ratio of the first thermal conductivity signal to that of the second thermal conductivity can be calculated to obtain a primary “vapor” signal. The “vapor” ratio can then be compared to an “air” ratio of air without the vapor at the first temperature and the second temperature to obtain a secondary signal thereof. Such a secondary signal can then be compared to an alarm set-point value to thereby determine whether the vapor comprises a flammable vapor and a risk-reducing action thereof be taken.

Abstract: Of a gas detector 100, a chamber 105 formed between a center cover 150 and a cover 160 is a part of an air flow channel AF. A first shielding plate 165 is provided in the chamber 105. Water droplets that have entered the chamber from a chamber entrance 103 with air hit and adhere to an entrance-opposed surface 165E of the first shielding plate 165. The water thus adhering to the surface is pushed by the air flowing along the entrance-opposed surface 165E and by gravity, to thereby advance downward. The water then drips downward and is accumulated on a bottom wall surface 105WD which serves as an upper surface of a bottom wall section 161WD. The water is pushed by the flow of air, to thereby advance toward a chamber exit 104. The water is then drained downward from the chamber exit 104.

Abstract: A modular materials characterization apparatus includes a sensor array disposed on a substrate, with a standardized array and contact pad format; electronic test and measurement apparatus for sending electrical signals to and receiving electrical signals from the sensor array; an apparatus for making electrical contact to the sensors in the standardized array format; an apparatus for routing signals between one or more selected sensors and the electronic test and measurement apparatus and a computer including a computer readable having a computer program recorded therein for controlling the operator of the apparatus. The sensor array is preferably arranged in a standardized format used in combinatorial chemistry applications for rapid deposition of sample materials on the sensor array.

Abstract: A combustible gas sensor includes an active element in electrical connection with a measurement circuit. The measurement circuit includes a thermistor network to compensate for the effect of changes in ambient temperature to the resistance of the active element. Another combustible gas sensor includes an active element having a geometric surface area no greater than approximately 0.5 mm2 in electrical connection with a measurement circuit. The measurement circuit includes a compensator that compensates for the effect of changes in ambient temperature to the resistance of the active element without compensating for heat lost by thermal conduction from the active element.

Abstract: A breath alcohol measuring device in which errors in operation can be recognized and more accurate measurement results can be obtained. The device includes a flow chamber for receiving the exhaled breathing gas volume of a person being tested and is provided with a flow diaphragm. A differential pressure sensor (4) bridges over the flow diaphragm, with a first measuring connection of the differential pressure sensor (4) connected via a first gas line (5) to the interior space of the flow chamber (2) upstream of the flow diaphragm (3), and a second measuring connection of the differential pressure sensor (4) is connected via second and third gas lines (12, 15) and a breath alcohol sensor (8) to the interior space of the flow chamber (2) downstream of the flow diaphragm (3). A throttling element (14) is present in the second gas line (12).

Abstract: A vapor sensing device that is sufficiently small and lightweight to be handheld, and also modular so as to allow the device to be conveniently adapted for use in sensing the presence and concentration of a wide variety of specified vapors. The device provides these benefits using a sensor module that incorporates a sample chamber and a plurality of sensors located on a chip releasably carried within or adjacent to the sample chamber. Optionally, the sensor module can be configured to be releasably plugged into a receptacle formed in the device. Vapors are directed to pass through the sample chamber, whereupon the sensors provide a distinct combination of electrical signals in response to each. The sensors of the sensor module can take the form of chemically sensitive resistors having resistances that vary according to the identity and concentration of an adjacent vapor.

Abstract: The mixed oxide WxMo1-xO3, where preferably x can be in the range 0.01 to 0.9, is very useful for the detection of oxidizing gases and in particular is superior for the detection of ozone. The preferred composition is in the range of 1% to 21% Mo (i.e. 99% to 79% W). The present example in which the composition of the sensing material is in the range WxMo1-xO3 with x varying from 0.01 to 0.9, is clearly distinct from the device claimed in applicant's earlier patent. Precipitation of the material as a mixed oxide from an aqueous solution of the ammonium metallates in concentrations of the appropriate stoichiometric proportions yields a powder that can be screen-printed to give an ideal microstructure. Resistivity of the material may be tailored to a desired value by adjusting the Mo/W ratio within the single phase field. Varying this ratio adjusts catalytic properties of the material.

Abstract: A monitoring system, such as used to monitor the presence and/or concentration of gases or other such fluids, includes a housing through which fluid is permitted to pass and which includes a heater element. The housing includes one or more vent hole/vent plug combinations and fluid, including gas and/or liquid, passes through the vent hole/vent plug combinations to flow into, through and/or out of the housing. A heater element is located in the housing and maintains the housing interior above the dew point to facilitate proper operation of the sensor element. The heater element, in conjunction with the vent hole/vent plug combinations, facilitates a heated-air plume through the housing to avoid the build up of moisture therein and to expose the sensor element to a steady stream of ambient atmosphere for monitoring the gas concentrations in same.

Abstract: A gas detector for sensing the presence of at least one predetermined gas is operative in conjunction with a electrical power source and includes a detection circuit, a temperature controller, and a electrical current controller, wherein the detection circuit includes a sensing device having first and second electrodes, the first electrode being connected to the power source for heating the first electrode, the temperature controller is operatively connectable to the detection circuit for maintaining a temperature of the first electrode at a predetermined magnitude, and the current controller is operatively connectable to the detection circuit for maintaining a current in the second electrode at a predetermined magnitude.

Abstract: A method for eliminating interference when analyzing a test sample of a bulk inert gas in an ion mobility spectrometer is disclosed which includes the steps of providing an ionization source for the spectrometer to form ions of the bulk inert gas, mixing a reagent gas with the test sample prior to entry into the spectrometer to alter the nature of the ions formed by the bulk inert gas to shift the location of a bulk inert gas mobility peak such that a bulk inert gas mobility peak does not overlap with an impurity mobility peak of the ions of a trace impurity of interest, whereby bulk inert gas ions are quenched and a clusters of the reagent gas and the bulk gas are formed. Alternatively, the reagent gas may be mixed with the drift gas in the ion mobility spectrometer, rather than with the test sample.

Abstract: A galvanic measuring device for detecting oxygen content in a gas flow, having a sealed gas flow chamber and a layer of sodium chloride saturated sponge material lining the interior of the gas flow chamber, for providing a constant source of humidity to the chamber.

Abstract: A microfluidic component having a microfluidic channel is bonded to an electronics component having a circuit for processing signals related to the microfluidic component. In an embodiment, the electronics component is a prefabricated integrated circuit chip that includes signal processing and/or process control functionality. The bonding of the microfluidic component to the electronics component provides a modular architecture in which different combinations of microfluidic components and electronics components can be used to create customized processing and analysis tools.

Abstract: Binding between two members of a recognition pair, e.g. antigen-antibody is determined by utilizing a probe which includes a piezoelectric crystal with electrodes on two opposite faces of the crystal. The crystal carries one or more metal plates which may be the same or different than the electrodes, the metal plates having immobilized thereon a first member of a recognition pair. Binding of a second member of the recognition pair to the first member, or dissociation between the two members and release of the second member from the probe, causes a change of immobilized mass which results in a change to the probe's resonance frequency.

Abstract: The present invention is related to the sensing of analytes and in particular, to methods of determining, resolving, identifying, or quantitating such analytes once detected. This invention provides systems and methods for identifying analytes, comprising using an importance index to give greater weight to the responses from sensors that measure characteristics most useful for identification of analytes. In other aspects, the systems and methods are useful for increasing the stability of electronic nose systems by prolonging the predictive capability of the training set of known analytes. In still other aspects, the systems and methods are useful for detecting and responding to events correlated with the presence of an analyte.

Abstract: A gas sensor for sensing NOx having electrochemical cells wherein dielectric material surrounds electrolytes except where electrodes are attached. Thereby, the exhaust gas is effectively prevented from contacting the electrolytes of the sensor's electrochemical cells. With the use of this technique, signal cross talk is minimized while enhancing NOx sensing sensitivity. Further, the total number electrodes needed are reduced which allows for more complex sensors structures.

Abstract: Chemical sensors for detecting the activity of a molecule or analyte of interest is provided. The chemical sensors comprise and array or plurality of sensors that are capable of interacting with a molecule of interest, wherein the interaction provides a response fingerprint. The fingerprint can be associated with a library of similar molecules of interest to determine the molecule's activity and diffusion coefficient.

Abstract: Methods of extracting and removing hyperpolarized gas from a container include introducing an extraction fluid into the container to force the hyperpolarized gas out of an exit port. The hyperpolarized gas is forced out of the container separate and apart from the extraction fluid. Alternatively, if the fluid is a gas, a portion of the gas is mixed with the hyperpolarized gas to form a sterile mixed fluid product suitable for introduction to a patient. An additional method includes engaging a gas transfer source such as a syringe to a transport container and pulling a quantity of the hyperpolarized gas out of the container in a controlled manner. Another method includes introducing a quantity of liquid into a container and covering at least one predetermined internal surface or component with the liquid to mask the surfaces and keep the hyperpolarized gas away from the predetermined internal surface, thereby inhibiting any depolarizing affect from same.

Abstract: A Chemical Detector, a training method and a method for detecting a chemical or chemicals has been developed that uses invertebrate organisms trained to respond to targeted chemical odors.

Abstract: Sensors and methods of monitoring for the presence of gas phase materials by detecting the formation of films based on the gas phase material are disclosed. Advantageously, some gas phase materials preferentially deposit on specific surfaces. As a result, selective detection of those gas phase materials can be obtained by detecting films deposited on those detection surfaces. Examples of gas phase materials that may be detected include RuO4, IrO4 and RhO4.

Abstract: A sensor for detecting the instantaneous concentrations of a plurality of gas constituents of a gas, which contains a first zone in which the instantaneous concentration of oxygen is measured, a second zone in which the instantaneous concentration of NH3 is measured, and a third zone in which the instantaneous concentration of NO is measured.

Abstract: A method for the detection of cell contents, the method comprising the steps of, introducing a cell into a channel in a microchip; lysing the cell to release cell contents into the channel; moving the cell contents towards a detection zone; and detecting the cell contents at the detection zone. An apparatus for the detection of cell contents, the apparatus comprising: a microchip; a cell mobilization channel formed in the microchip, the cell mobilization channel having a cell introduction end and a detection end; a cell mobilizer operably connected with the cell introduction end for moving cells from the cell introduction end to the detection end; means for lysing cells in the cell mobilization channel at a lysing zone, the lysing zone being located between the cell introduction end and the detection end; and a detector, disposed adjacent the detector end, arranged to detect cell contents appearing at the detector end that have been moved from the lysing zone to the detector end by the cell mobilizer.

Abstract: There is provided a gas concentration-detecting device for detecting the concentration of gas in oil, which is capable of detecting the concentration of gas in oil with accuracy, irrespective of the temperature of oil, and even when oil is degraded. The gas concentration-detecting device includes two electrodes for being arranged in the oil such that the electrodes are opposed to each other and spaced from each other by a predetermined distance, and a capacitance amplifier for outputting a signal indicative of a concentration of gas in oil, the signal being dependent on a capacitance between the electrodes. The predetermined distance between the electrodes is set to a value equal to or larger than a predetermined value at which an amount of drift of the signal output from the capacitance amplifier dependent on variation in a temperature of the oil starts to gradually decrease as the distance between the electrodes is increased.

Abstract: In a planar oxygen sensor having a pump cell, a reference cell, a sensor chamber and a heating device, a ground plane electrode is provided and includes a sensing portion having a first sense lead and a second sense lead and a measuring portion having a first measuring lead and a second measuring lead, wherein the first measuring lead and the second measuring lead have increased surface area relative to said sensing portion such that the resistance between the first measuring lead and the second measuring lead is reduced and wherein the first measuring lead is disposed so as to be communicated with the first sense lead and the second measuring lead is disposed so as to be communicated with the second sense lead.

Abstract: The present invention relates to a filtration-detection device for detecting or quantifying an analyte in a test sample including a filtration device having a first binding material immobilized thereto, wherein the first binding material is capable of binding to a portion of the analyte, and a detection assembly positioned relative to the filtration device to detect or quantify analyte bound to the first binding material. The present invention also relates to methods of using the filtration-detection device.

Abstract: Chemically sensitive sensors, suitable for detecting analytes in fluids (in gaseous or liquid phase), wherein the chemically sensitive sensors comprise a chemically sensitive probe, which comprises one or a blend of several arylene alkenylene oligomers.

Abstract: Method and apparatus suited to convenient field use for heating a porous metallic substrate swiped on the surface of an article possibly bearing residue of contraband or other target chemical substances. The preferred embodiment of the device includes means for holding the swiped substrate between electrodes bearing opposite electrical charges, thereby completing an electrical circuit in which current can flow through the porous metallic substrate. Resistance causes the substrate to heat, thus driving adherent target chemicals, if present, into a space from which they are carried via gas flow into a detector such as a portable IMS for analysis.

Abstract: The subject invention pertains to a method and apparatus for sensing nitroaromatics. The subject invention can utilize luminescent, for example fluorescent and/or electroluminescent, aryl substituted polyacetylenes and/or other substituted polyacetylenes which are luminescent for sensing nitroaromatics. In a specific embodiment, the subject invention can utilize thin films of flourescent and/or electroluminescent aryl substituted polyacetylenes and/or other substituted polyacetylenes which are fluorescent and/or electroluminescent. In a specific embodiment, the fluorescence from thin films of flourescent, substituted polyacetylene, such as—poly-[1-phenyl-2-(4-trimethylsilylphenyl)ethyne] (PTMSDPA) is strongly quenched by the vapors of a variety of nitroaromatic compounds present at levels ranging from parts-per-million to parts-per-billion in air.

Abstract: A method for preparing tungsten trioxide precursor and a hydrogen sulfide gas sensor made thereof. The method includes dissolving a soluble tungsten compound in a solvent to form a solution; and adding thickener to the solution to adjust the viscosity thereof. In the above method, the viscosity of the produced tungsten trioxide precursor is adjusted so that it can be coated onto a substrate by spin or screen coating. The substrate is then thermal processed to decompose the organic component to obtain tungsten trioxide. A conventional method is then applied to fabricate a hydrogen sulfide gas sensor.

Abstract: A base is provided with a concave and three leads, and the central lead is bent to the side opposite to the concave, and the other leads are bent to the side of the concave. A central electrode of a sensor element is attached to the central lead and the bottom of the concave and a coil serving as both a heater and an electrode is attached to the other leads to support the sensor element on a small base at four points.

Abstract: An exhaust gas sensor includes a housing and a sensor element supported by the housing. The sensor element includes a support member having an exhaust side, a reference side, and an aperture extending through the support member between the exhaust side and the reference side. The sensor element further includes an exhaust-side electrode on the exhaust side of the support member. The exhaust-side electrode is electrically connected to a contact on the reference side of the support member via a lead extending through the aperture. The aperture is sealed around the lead such that gas cannot pass through the aperture. The support member is oriented substantially parallel to the flow of exhaust gases when the exhaust gas sensor is installed on a vehicle. The sensor further includes a contact pin in the housing that engages the contact and biases the sensor element against a portion of the housing.

Abstract: A method and a device are described for producing and/or screening composite arrangements, especially of layer [laminated; coated] composite arrangements, with respect to one desired property, a plurality of composite arrangements (16a, 16b, . . . , 26a, 26b, . . . ) being produced in continuous form, in that on a substrate (10, 20) at at least two defined points (11a, and 11b, . . . , 21a, 21b, . . . ) at least one educt is applied in each case for at least two different materials and the latter are synchronously subjected to the same reaction conditions for the formation of the materials. In this context, one material along with one point (11a, the 11b, . . . , 21a, 21b, . . . ) of the substrate constitutes one composite arrangement (16a, 16b, . . . , 26a, 26b, . . . ). A change in one property of each composite arrangement (16a, 16b, . . . 26a, 26b, . . . ) is determined under the influence of an external stimulus, and the composite arrangement (16a, 16b, . . . , 26a, 26b, . . .

Abstract: A hydrocarbon sensor and collector. An element that is capable of absorbing and releasing hydrocarbons is positioned in the air intake system of a vehicle, upstream from the engine and wholly in the airflow. The element has a plurality of chambers defined in it that allow air to pass through the element. The hydrocarbon sensor and collector also includes a means for detecting the level of hydrocarbons absorbed by the element.

Abstract: The present invention includes free-standing, shaped ceramic-bearing bodies useful in fluid sensors, filters, and catalyst devices. The invention also includes methods and processes for using such devices. In a preferred embodiment of the invention, shaped metallic foils are converted into free-standing, porous rutile foils having an open pore structure by oxidation at an elevated temperature. The exposure of such foils to increasing concentrations of reducing gases such as carbon monoxide results in an increase in the steady-state electrical resistance. The resultant ceramic-bearing bodies may be used as effective sensors of reducing gas species in such applications as automobile and industrial emissions.

Abstract: In a catalytic sensor, a bead is located within a can having an aperture in its front surface. The bead is surrounded by thermally insulating material such as glass fiber and a filter material is arranged between the bead and the aperture in the can. This acts to remove H2S or other inhibiting gases before they reach the bead and impair its performance. The thermally insulating material allows the filter material to be included whilst still permitting the bead to be operated at a high temperature.

Abstract: In a gas sensor, a casing which accommodates a sensing element includes an inner cylindrical member and an outer cylindrical member which are caulked together by means of a caulked portion. The Vickers hardness H1 of the inner cylindrical member is Hv 250 to 430; the Vickers hardness H2 of the outer cylindrical member is Hv 160 to 330; and the hardness difference “H1-H2” is not less than 30. Through employment of the above ranges of H1 and H2, the caulked portion can maintain good airtightness even in a working environment involving, for example, thermal shocks.

Abstract: The invention relates to a method for detecting analytes and to a device for carrying out the method, for use for analysis or diagnosis in the fields of chemistry, biochemistry, molecular genetics, food chemistry, biotechnology, the environment and medicine. Marker particles (5) with different electrical properties or a different relative permeability to those of the measuring solution (3) surrounding them are used to detect the analytes (8). The marker particles (5) either bond specifically to the analytes (8) or to a base (2) in competition with the analyte. The analytes (8) are detected by the changes in an electrical field or an electrical current generated by electrodes (2) or in an electrical voltage applied to an electrode or in a magnetic field, said changes being caused by marker particles which have bonded with the analytes or by marker particles which have instead bonded to the base in an electrical field.

Abstract: A QCM sensor including a sensor device, the sensor device having a crystal substrate, on both of front and rear surfaces of which a pair of electrodes are disposed so as to oppose with each other and the QCM sensor detecting and quantitatively analyzing components of a sample from either a variation in a fundamental resonant frequency or a variation in an impedance when a surface of one of the pair of electrodes is immersed into either a sample gas or a sample solution. The sensor device is arranged in a multi-channel structure such that four mutually opposing electrodes (11A through 14A, 12B through 14B) are disposed on both front and rear surfaces of the crystal substrate 10, each electrode being arranged to enable a fixation of a receptor which is different for each component of a sample to be detected and quantitatively analyzed, whereby the QCM sensor detects and quantitatively analyzes once the components of one sample different for different electrodes.

Abstract: A humidity sensor 10 with high assembling properties and environmental resistance comprises a detecting element 14 having electrodes 14a and 14b formed on a base, conducting wires 12 and 13 connected individually to the electrodes by means of resin conductors formed of an organic high-molecular resin having an electrically conductive material dispersed therein, and a holding member 11 of an organic high-molecular resin for holding the detecting element and the conducting wires. The holding member has a connecting aperture 11c through which junctions between the electrodes and the conducting wires are exposed.

Abstract: Chemical sensors for detecting analytes in fluids comprising a plurality of alternating nonconductive regions (comprising a nonconductive material) and conductive regions (comprising a conductive material). In preferred embodiments, the conducting region comprises a nanoparticle. Variability in chemical sensitivity from sensor to sensor is provided by qualitatively or quantitatively varying the composition of the conductive and/or nonconductive regions. An electronic nose for detecting an analyte in a fluid may be constructed by using such arrays in conjunction with an electrical measuring device electrically connected to the conductive elements of each sensor.