Abstract: An exemplary embodiment of a method of detecting hydrocarbons in Systems and methods for sensing analytes in an aqueous solution, include pretreating a water sample to provide a test sample. A flow cell includes at least one sensor with a polymer coating having at least partial selectivity for at least one analyte. The flow cell receives a test sample and a reference sample. At least one output signal from the at least one sensor is processed with a microcontroller using a model of the sensor response and a bank of Kalman filters to estimate a concentration of at least one analyte in the aqueous solution.

Abstract: An exemplary embodiment of a method of detecting hydrocarbons in Systems and methods for sensing analytes in an aqueous solution, include pretreating a water sample to provide a test sample. A flow cell includes at least one sensor with a polymer coating having at least partial selectivity for at least one analyte. The flow cell receives a test sample and a reference sample. At least one output signal from the at least one sensor is processed with a microcontroller using a model of the sensor response and a bank of Kalman filters to estimate a concentration of at least one analyte in the aqueous solution.

Abstract: There is provided an optical detection system (100) comprising a photodetector (110) and a substrate (120). The substrate (120) comprises an aperture array (121) wherein light is transmittable to the photodetector (110) via the apertures (122) of the substrate (120) only, and the apertures (122) are functionalised to provide capture of a target analyte (151) at an aperture such that capture of an analyte at an aperture causes attenuation of light at said aperture. The photodetector (110) being configured to detect the capture of an analyte at an aperture of the aperture array by detecting attenuation at an aperture. The system comprises a lensless detection system.

Abstract: Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.

Abstract: A process for a pre-concentration unit including: a sorbent material coated passage-way having an entrance for receiving a hydrocarbon-containing groundwater sample and for pre-concentrating the hydrocarbons in a hydrocarbon-containing groundwater sample by successive sorption/desorption cycles, and having an exit for discharging the pre-concentrated hydrocarbons; a heating unit for heating the sorbent material coated passage-way; and; an array of shear horizontal-surface acoustic wave sensors with coatings adapted for detecting and quantifying the pre-concentrated hydrocarbons, disposed at the exit of the sorbent material coated passage-way; and a housing for enclosing the pre-concentration unit and the array of shear horizontal-surface acoustic wave sensors, adapted for continuous use at a body of hydrocarbon-containing groundwater, and coupled to mathematical methods for generating concentrations of specific analytes from both transient and steady-state signals.

Abstract: Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.

Abstract: A process for a pre-concentration unit including: a sorbent material coated passage-way having an entrance for receiving a hydrocarbon-containing groundwater sample and for pre-concentrating the hydrocarbons in a hydrocarbon-containing groundwater sample by successive sorption/desorption cycles, and having an exit for discharging the pre-concentrated hydrocarbons; a heating unit for heating the sorbent material coated passage-way; and; an array of shear horizontal-surface acoustic wave sensors with coatings adapted for detecting and quantifying the pre-concentrated hydrocarbons, disposed at the exit of the sorbent material coated passage-way; and a housing for enclosing the pre-concentration unit and the array of shear horizontal-surface acoustic wave sensors, adapted for continuous use at a body of hydrocarbon-containing groundwater, and coupled to mathematical methods for generating concentrations of specific analytes from both transient and steady-state signals.

Abstract: Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.

Abstract: The present invention discloses an electrochemical device for detecting single particles, and methods for using such a device to achieve high sensitivity for detecting particles such as bacteria, viruses, aggregates, immuno-complexes, molecules, or ionic species. The device provides for affinity-based electrochemical detection of particles with single-particle sensitivity. The disclosed device and methods are based on microelectrodes with surface-attached, affinity ligands (e.g., antibodies, combinatorial peptides, glycolipids) that bind selectively to some target particle species. The electrodes electrolyze chemical species present in the particle-containing solution, and particle interaction with a sensor element modulates its electrolytic activity. The devices may be used individually, employed as sensors, used in arrays for a single specific type of particle or for a range of particle types, or configured into arrays of sensors having both these attributes.

Abstract: An improved microfluidics device and system for sample loading and injection are disclosed. The device includes three main channels—a separation channel, supply channel, and drain channel—for use in loading and injecting a sample from the supply channel. Pairs of peripheral channels connecting the supply channel with upstream and downstream regions of the separation channel, and connecting supply and drain channels to a downstream region of the separation channel promote fluid flow and/or ion in the channel network to effect (i) sample shaping in the separation channel, when an electrokinetic or pneumatic force is applied between the supply and drain channels, and (ii) sample pullback in the supply and drain channels, when an electrokinetic or pneumatic force is applied between opposite ends of the separation channel. The system incorporates the device, electrodes that interact with reservoirs in the device, and a control unit.

Abstract: The present invention discloses an electrochemical device for detecting single particles, and methods for using such a device to achieve high sensitivity for detecting particles such as bacteria, viruses, aggregates, immuno-complexes, molecules, or ionic species. The device provides for affinity-based electrochemical detection of particles with single-particle sensitivity. The disclosed device and methods are based on microelectrodes with surface-attached, affinity ligands (e.g., antibodies, combinatorial peptides, glycolipids) that bind selectively to some target particle species. The electrodes electrolyze chemical species present in the particle-containing solution, and particle interaction with a sensor element modulates its electrolytic activity. The devices may be used individually, employed as sensors, used in arrays for a single specific type of particle or for a range of particle types, or configured into arrays of sensors having both these attributes.

Abstract: A method and apparatus for performing a plurality of small-volume reactions simultaneously with components in a bulk-phase medium are disclosed. The apparatus includes a device having an elongate or planar channel providing a plurality of discrete small-volume reaction regions within the channel, each communicating with supply and hold reservoirs from which material can be introduced into the regions, and to which material can be transferred from the reaction regions. A reaction-specific reagent is carried on a wall portion of each reaction region, or in a reservoir associated with a reaction region, for reacting in solution with one or more components in the bulk-phase medium, to effect a selected solution-phase reaction in each region or in a region-specific reservoir associated therewith.

Abstract: A microchannel apparatus and method for processing a sample are disclosed. The apparatus include a multisite reaction channel, one or more sample-preparation stations upstream of the reaction channel, for carrying out one or more selected sample-preparation steps effective to convert a sample to the bulk-phase medium, and one or more product-processing stations downstream of the reaction channel, for processing products generated in one or more of the reaction regions. Also included is structure for transferring solvent or solvent components between one of the sample-preparation stations and one or more selected reaction regions in the reaction channel, and between one or more selected reaction regions in the reaction channel and one of said product-processing stations, under the control of a control unit.

Abstract: A microfluidic device having integrated components for conducting chemical operations. Depending upon the desired application, the components include electrodes for manipulating charged entities, heaters, electrochemical detectors, sensors for temperature, pH, fluid flow, and other useful components. The device may be fabricated from a plastic substrate such as, for example, a substantially saturated norbornene based polymer. The components are integrated into the device by adhering an electrically conductive film to the substrate. The film may be made of metal or an electrically conducting ink and is applied to the device through metal deposition, printing, or other methods for applying films. Methods for reducing bubble formation during electrokinetic separation and methods for heating material in a microfluidic device are also disclosed.

Abstract: A substrate having a dendrimer monolayer film thereon is provided. The film can comprise either dendrimers, or dendrons (dendrimer branches). In each case, the monolayer films are covalently bonded to the desired surface. The resulting structure can be employed in a variety of applications including chemical sensors.

Abstract: An improved microfluidics device and system for sample loading and injection are disclosed. The device includes three main channels—a separation channel, supply channel, and drain channel—for use in loading and injecting a sample from the supply channel. Pairs of peripheral channels connecting the supply channel with upstream and downstream regions of the separation channel, and connecting supply and drain channels to a downstream region of the separation channel promote fluid flow and/or ion in the channel network to effect (i) sample shaping in the separation channel, when an electrokinetic or pneumatic force is applied between the supply and drain channels, and (ii) sample pullback in the supply and drain channels, when an electrokinetic or pneumatic force is applied between opposite ends of the separation channel. The system incorporates the device, electrodes that interact with reservoirs in the device, and a control unit.

Abstract: Optical apparatus for forming correlation spectrometers and optical processors. The optical apparatus comprises one or more diffractive optical elements formed on a substrate for receiving light from a source and processing the incident light. The optical apparatus includes an addressing element for alternately addressing each diffractive optical element thereof to produce for one unit of time a first correlation with the incident light, and to produce for a different unit of time a second correlation with the incident light that is different from the first correlation. In preferred embodiments of the invention, the optical apparatus is in the form of a correlation spectrometer; and in other embodiments, the apparatus is in the form of an optical processor. In some embodiments, the optical apparatus comprises a plurality of diffractive optical elements on a common substrate for forming first and second gratings that alternately intercept the incident light for different units of time.

Abstract: A combustible gas sensor that uses a resistively heated, noble metal-coated, micromachined polycrystalline Si filament to calorimetrically detect the presence and concentration of combustible gases. The filaments tested to date are 2 .mu.m thick.times.10 .mu.m wide.times.100, 250, 500, or 1000 .mu.m-long polycrystalline Si; some are overcoated with a 0.25 .mu.m-thick protective CVD Si.sub.3 N.sub.4 layer. A thin catalytic Pt film was deposited by CVD from the precursor Pt(acac).sub.2 onto microfilaments resistively heated to approximately 500.degree. C.; Pt deposits only on the hot filament. Using a constant-resistance-mode feedback circuit, Pt-coated filaments operating at ca. 300.degree. C. (35 mW input power) respond linearly, in terms of the change in supply current required to maintain constant resistance (temperature), to H.sub.2 concentrations between 100 ppm and 1% in an 80/20 N.sub.2 /O.sub.2 mixture. Other catalytic materials can also be used.

Abstract: A combustible gas sensor that uses a resistively heated, noble metal-coated, micromachined polycrystalline Si filament to calorimetrically detect the presence and concentration of combustible gases. A thin catalytic Pt film was deposited by CVD from the precursor Pt(acac).sub.2 onto microfilaments resistively heated to approximately 500 .degree. C.; Pt deposits only on the hot filament. The filaments tested to date are 2 .mu.m thick .times.10 .mu.m wide .times.100, 250, 500, or 1000 .mu.m-long polycrystalline Si; some are overcoated with a 0.25 .mu.m-thick protective CVD Si.sub.3 N.sub.4 layer.

Abstract: A method for preventing micromechanical structures from adhering to another object includes the step of immersing a micromechanical structure and its associated substrate in a chemical species that does not stick to itself. The method can be employed during the manufacture of micromechanical structures to prevent micromechanical parts from sticking or adhering to one another and their associated substrate surface.