Abstract: An object of the present invention is to suppress variations in measurement values when measuring a specific binding reaction between a physiologically active substance and a tested substance using a surface plasmon resonance measurement device, so that binding detection data with high reliability is obtained. The present invention provides a method for measuring a change in surface plasmon resonance, which comprises: using a surface plasmon resonance measurement device comprising a flow channel system having a cell formed on a metal film and a light-detecting means for detecting the state of surface plasmon resonance by measuring the intensity of a light beam totally reflected on the metal film; and exchanging the liquid contained in the above flow channel system, wherein a major axis of the metal film is 0.

Abstract: The invention is a method of measuring oxygen concentration in a package having an oxygen sensitive product disposed therein. The method includes exposing a luminescent compound that is disposed in an interior of the package to light having a wavelength that is absorbed by the luminescent compound so that the luminescent compound is promoted into an excited state. When the exposure of the light is terminated, the excited luminescent compound emits light that is detectable by a detector positioned outside of the package. The intensity of the emitted light is inversely proportional to the oxygen concentration and is used in conjunction with mathematical function that describes the luminescent intensity of the luminescent compound as a function of oxygen concentration and temperature to calculate the oxygen concentration. The method may be used to verify and track the oxygen concentration of a package as it moves through a distribution system.

Abstract: The methods and apparatus 100, disclosed herein are of use for sequencing 150 and/or identifying 160 proteins 230, 310, polypeptides 230, 310 or peptides 230, 310. Proteins 230, 310 containing labeled amino acid residues may be synthesized and passed through nanopores 255, 330. A detector 257, 345 operably coupled to a nanopore 255, 330 may detect labeled amino acid residues as they pass through the nanopore 255, 330. Distance maps 140 for each type of labeled amino acid residue may be compiled. The distance maps 140 may be used to sequence 150 and/or identify 160 the protein 230, 310. In different embodiments of the invention, amino acid residues labeled with luminescent labels 235, 245 or nanoparticles 315 may be detected using photodetectors 257 or electrical detectors 345. Apparatus 100 of use for protein 230, 310 sequencing 150 and/or identification 160 are also disclosed herein.

Abstract: The invention makes it possible to measure binding of a biochemical substance with a high throughput and with high sensitivity using a small cell capable of being filled with a small amount of chemical solution. A space between a first substrate and a second substrate such that probes are immobilized on their mutually facing planes is used as a cell that houses a specimen solution. Light is irradiated from a first substrate side, and reflected light is subjected to spectroscopy. Binding of the target with the probe is detected by a wavelength shift in the reflection spectrum.

Abstract: Optical detection of molecules using a biochip having at least one reagent immobilizing area designed to receive one or more reagents and at least one calibration structure with a predetermined height to provide a height reference for optical measurement is disclosed. When the calibration structure is illuminated by a probe beam of light, a first reflected beam of light is reflected off the calibration structure, and a second reflected beam of light is reflected off the reagent immobilizing area. The first reflected beam and the second reflected beam are compared to determine a height at the reagent immobilizing area.

Abstract: The present invention provides a sensor device for detecting a substance contained in a fluid comprising a first photonic crystal region, a second photonic crystal region, a first channel which is connected to the first photonic crystal region, and passes the fluid containing the substance therein, a second channel which is connected to the second photonic crystal region, and passes a fluid for reference therein, an optical waveguide which is connected to the first photonic crystal region and the second photonic crystal region, and guides light, and a detecting section for detecting a difference between a light which has passed through the optical waveguide and the first photonic crystal region and a light which has passed through the optical waveguide and the second photonic crystal region.

Abstract: Embodiments of optofluidic devices or methods according to the application can provide on-chip, label-free, massively parallel analysis of analytes. An embodiment of the optofluidic device can comprise a microresonator, a waveguide optically coupled to the microresonator, and a fluidic channel that exposes an analyte to an evanescent field from the microresonator, wherein the light signal has a linewidth lesser than the width of at least one resonance of the light signal propagating in the microresonator. The light signal can be tuned across a spectrum of light wavelengths, wherein the spectrum of wavelengths includes one or more wavelengths defining the at least one resonance in the microresonator. The light transmission through the waveguide over the spectrum of wavelengths of the input light can be detected, and an absorption spectrum of the analyte can be determined.

Abstract: The invention concerns a device for enhancing fluorescence comprising a support (10) carrying fluorescence enhancement means (11), the fluorescence enhancement means offering a reception surface for chemical or biological elements intended to be read by detection of a fluorescence signal emitted by a fluorophore, associated with the chemical or biological elements, under the effect of an excitation light beam. The fluorescence enhancement means (11) is made up of a thin, transparent, dielectric layer or a stack of thin, transparent, dielectric layers (12 to 16) ensuring a mirror function for the fluorescence signal and excitation light beam, the material of the thin layer or of each thin layer of the stack being chosen from among the following materials: TiO2, Ta2O5, HfO2, ZrO2, MgO, SiO2, Si3N4, MgF2 and YF3. The fluorescence enhancement device may be used for a biological or chemical optic sensor.

Abstract: Integrated photoluminescence (PL)-based chemical and biological sensors are provided comprising a photodetector (PD), a long-pass filter, an excitation source, and a sensing element, all based on thin films or structures. In one embodiment the light source is an organic light emitting device (OLED) and the sensing element is based on thin films or solutions in microfluidic channels or wells. The PD and optical filters are based on thin film amorphous or nanocrystalline silicon and related materials. In another embodiment, sensor components are fabricated on transparent substrates, which are attached back-to-back to generate a compact, integrated structure.

Abstract: A method for detecting binding of biological and/or chemical components of liquid or gaseous mixtures and solutions, which are of mainly biological origin and/or determine parameters of living activity of biological objects, to substances that bind said components due to a biological, chemical or physical interaction; and analysis of mixtures and solutions to determine presence of biological and/or chemical components. Binding substances are arranged on a surface of or inside a sensor layer, which changes its thickness due to the binding being detected; the layer is affected by light of different wavelengths; a signal due to interference on the sensor layer is registered in the reflected or transmitted light.

Abstract: A liquid analyser has a reactor portion and an associated measurement portion. A sample pump is operable to deliver a liquid sample to a reactor vessel. A base pump supplies a base solution to the reactor vessel. An ozone generator supplies ozone to the reactor vessel. The liquid sample is oxidised in the reactor vessel by means of hydroxyl radicals which are generated using the base solution and ozone to reduce complex components of the liquid sample to their lowest state in solution. The oxidised sample solution is delivered to an optical detector in the measurement portion to determine the concentration of one or more selected materials such as nitrogen, phosphorous or a heavy metal in the oxidised sample solution.

Abstract: A device includes a planar optical waveguide, as part of a sensor platform, and, connected to the platform directly or by means of a sealing medium, a sealing layer. The sealing layer forms either directly or by means of a sealing medium a tightly sealing layer. The sealing layer includes a multitude of recesses at least open towards the sensor platform, which form a corresponding multitude of sample compartments in a 2-dimensional arrangement.

Abstract: Provided herein are methods and systems for detecting biomolecular binding events using gigahertz or terahertz radiation. The methods and systems use low-energy spectroscopy to detect biomolecular binding events between molecules in an aqueous solution. The detected biomolecular binding events include, for example, nucleic acid hybridizations, antibody/antigen binding, and receptor/ligand binding.

Abstract: The invention provides a method and apparatus for separating blood into components, may be expanded to include other types of cellular components, and can be combined with holographic optical manipulation or other forms of optical tweezing. One of the exemplary methods includes providing a first flow having a plurality of blood components; providing a second flow; contacting the first flow with the second flow to provide a first separation region; and differentially sedimenting a first blood cellular component of the plurality of blood components into the second flow while concurrently maintaining a second blood cellular component of the plurality of blood components in the first flow. The second flow having the first blood cellular component is then differentially removed from the first flow having the second blood cellular component.

Abstract: A sensor for sensing at least one biological target or chemical target is provided. The sensor includes a membrane includes a membrane material that supports generation and propagation of at least one waveguide mode, where the membrane material includes a plurality of voids having an average size<2 microns. The sensor also includes at least one receptor having structure for binding to the target within the plurality of voids, and an optical coupler for coupling light to the membrane sufficient to generate the waveguide mode in the membrane from photons incident on the optical coupler.

Abstract: An assay system having a channel bounded by first and second reflective surfaces adapted to accommodate a fluid material therebetween and defining a plurality of regions in an array between those surfaces with each region defining a resonant cavity and adapted to receive a capturing material on a surface thereof whereby a source of radiation illuminates each region to provide a standing wave of radiation of within the cavity indicative of binding of said capturing agent to material under investigation, a binding thereof being detected in response to radiation from each cavity indicative of a change in the standing wave pattern.

Abstract: The present invention provides, a system and method for unobtrusively determining water content within a fuel cell. One embodiment of a system in accordance with the present invention includes a fuel cell body including an ionomeric membrane, water and a fluorophore contained therein. The system further includes a medium for permitting light transfer therein, such as an optical fiber, having opposing ends, wherein one end contacts or is disposed in a portion of the ionomeric membrane and the other end extends from the fuel cell body. The other end is preferably divided into at least two portions, one portion being operatively associated with a light source, and another portion being operatively associated with a spectrometer.

Abstract: Magnetic particles with a metal coat holding target substance captors are made to react with a target substance contained in a specimen in a solution where the magnetic particles are dispersed in a liquid medium. Subsequently, the dispersion of the magnetic particles is applied to a surface having a periodic structure that is adapted to generate plasmon resonance and a change in the plasmon resonance attributable to the concentration of the target substance held on the magnetic particles fixed magnetically to the surface is optically detected to determine the concentration of the target substance in the specimen.

Abstract: A system and method for detecting mass based on a frequency differential of a resonating micromachined structure, such as a cantilever beam. A high aspect ratio cantilever beam is coated with an immobilized binding partner that couples to a predetermined cell or molecule. A first resonant frequency is determined for the cantilever having the immobilized binding partner. Upon exposure of the cantilever to a solution that binds with the binding partner, the mass of the cantilever beam increases. A second resonant frequency is determined and the differential resonant frequency provides the basis for detecting the target cell or molecule. The cantilever may be driven externally or by ambient noise. The frequency response of the beam can be determined optically using reflected light and two photodetectors or by interference using a single photodetector.

Abstract: A surface plasmon resonance assay apparatus is loaded with a sensor unit. A sensing surface of a thin film detects reaction of a sample. A dielectric prism is overlaid with the thin film to constitute an interface. A reflection angle upon occurrence of attenuated total reflection of the illuminating light is changeable according to reaction of the sample on the sensing surface. Protecting panels are disposed to face outer surfaces of the prism, for covering and protecting at least partially the outer surfaces. A first window in one of the protecting panels is positioned on a path of the illuminating light traveling for incidence on the interface, for passing the illuminating light. A second window in one remaining protecting panel is positioned on a path of the illuminating light traveling upon reflection by the interface, for passing the illuminating light.

Abstract: A sensor is provided which comprises a waveguide for allowing an electromagnetic wave to propagate therethrough and disposing an object at a plurality of positions thereof, and a detecting portion for detecting the electromagnetic wave which has interacted with the object at the plurality of positions and propagated through the waveguide, wherein a property of the object is analyzed or identified based on an information obtained from the electromagnetic wave detected by the detecting portion. Thereby, accurate detection can be effected even when the amount of an object is small.

Abstract: A one- or two-dimensional arrangement of flow cells is provided, as part of an array of sample compartments, with at least one inlet and outlet for each sample compartment, formed by a base plate and a body, with an arrangement of spatial recesses corresponding to the (geometrical) arrangement of the sample compartments, combined with the base plate. The arrangement allows for supplying to or removing from the sample compartments, which can be arranged at a high quantity on a small base area, even very small amounts of samples or reagents.

Abstract: The present invention is directed to a waveguide sensor as well as to an evanescent field induced evanescent field induced sensor system for use in diagnostic housing and an integrated waveguide sensor comprising: a waveguide layer,—capture compounds applied on the upper surface of said waveguide layer for 5 specific bonding to target substances,—a cladding layer surface of said waveguide layer,—a filter which is transmitting for luminescent radiation while absorbs and/or reflects radiation of excitation radiation, wherein the filter is arranged below the lower 10 surface of said cladding layer, at least one detector for sensing luminescent radiation, wherein the detector is arranged below the lower surface of said filter, a substrate that is connected with the detector and comprises the electrical interface of said detector; wherein 15 between the upper surface of the waveguide layer and along at least a lower surface section of the housing a channel is formed for receiving a fluidic probe; and the luminesce

Abstract: In a sensor device and a sensing method capable of simultaneously extracting plural pieces of information including information about the presence/absence, distribution, and so on, of targets, in case of measuring changes in nature of a detecting portion (11) upon coupling with targets (a and b), information about changes in quantities of the targets (a and b) with time is extracted in addition to information about the presence/absence, distribution, and so on, of the targets (a and b) from geometrical structures of the detecting portion (11), such as locations and/or shapes of bonding sites (A and B) for selectively coupling with the targets (a and b), respectively.

Abstract: An assay technique for label-free, highly parallel, qualitative and quantitative detection of specific cell populations in a sample and for assessing cell functional status, cell-cell interactions and cellular responses to drugs, environmental toxins, bacteria, viruses and other factors that may affect cell function.

Abstract: The invention provides a luminescent based sensor having a luminescent material optically coupled to a substrate, and adapted to be used in a medium or environment such as water or air. A detector is provided to detect light that is emitted into the substrate by the material. The substrate is adapted to redirect light that is emitted into the substrate at angles with the range ?esc ? ? ? ?lsc where ?esc is the critical angle of the environment/substrate interface and ?lsc is the critical angle of the luminescent layer/substrate interface. Examples of possible configurations are described.

Abstract: Optical time domain reflectometry caused by absorption of a volatile or analyte into the fiber optic cladding is used an optical nose. The fiber optics (14) are covered with a gas permeable film (44) which is patterned to leave millimeter wide gas permeable notches (48a-48d). The notches contain a sensing polymer that responds to different gases by expanding or contracting.

Abstract: Optical assay apparatus and methods are provided having an optical assay cup for detecting analytes in a sample fluid. The cup's sidewall may include an optical waveguide having a detection coating on its inner surface. During use, the waveguide receives evanescent or darkfield interrogation light, interrogates at least part of cup's interior volume with it, and emits signal light as a function of the analytes. The detection coating may have fluid or non-fluid detection layers, at least part of which may form at least part of a waveguide for the interrogation light. The cup may be spun during use, such as to centrifugally-concentrate any high-density analytes towards cup's sidewall. The assay apparatus may further include an interrogation light source, a cover or spinning apparatus for the cup, and an optical detector for the signal light.

Abstract: The invention is related to different embodiments of a kit for the simultaneous qualitative and/or quantitative determination of a multitude of analytes comprising a sensor platform comprising an optical thin-film waveguide with a layer (a) transparent at least at an excitation wavelength on a layer (b) with lower refractive index than layer (a), also transparent at least at said excitation wavelength, and at least one grating structure (c) modulated in said layer (a), for the incoupling of said excitation light into layer (a), at least one array of biological or biochemical or synthetic recognition elements immobilized in discrete measurement areas (d) directly or by means of an adhesion-promoting layer on layer (a), for specific recognition and/or binding of said analytes and/or for specific interaction with said analytes, means for laterally resolved referencing of the excitation light intensity available in the measurement areas, and optionally means for the calibration of one or more luminescences gen

Abstract: The invention provides a microfluidic device wherein capillaries are connected to the microfluidic device by a deformable penetrable substance.

Abstract: A biconically tapered optical fiber serves as a biosensor at all optical wavelengths of interest ranging from UV to far IR at subfemtogram per mL sensitivity. The biconically tapered sensor detects biomaterials such as pathogenic species, proteins and DNA and others biological analytes. Although it uses the principles of evanescent fields, absorption, adsorption, fluorescence capture and retransmission through the fiber, the detection at the sub-nanogram per mL level is achieved primarily by adsorption or a surface activity due to a refractive index change. The geometry of the biconically tapered optical sensor affects its performance. The sensing modality is achieved in situ with a source connected at one end of a tapered fiber and a suitable detector at the other end. The tapered region is optionally immobilized with a recognition molecule such as an antibody to the target antigen or a complementary DNA strand. The sample is brought in contact with the tapered region either in batch mode or in a flow mode.

Abstract: The present invention describes (bio)chemo-functional waveguide grating structures consisting of at least one (bio)chemo-functional waveguide grating structure unit or at least one (bio)chemo-functional sensor location with beam guidance permitting light beam separation, as well as detection methods for parallel analysis which are marking-free or based on marking.

Abstract: The invention provides methods for fabricating calorimetric resonant reflection biosensors.

Abstract: An apparatus and method for detection of peak wavelength values of colorimetric resonant optical biosensors using tunable filters and tunable lasers is provided. Biomolecular interactions may be detected on a biosensor by directing collimated white light towards a surface of the biosensor. Molecular binding on the surface of the biosensor is indicated in a shift in the peak wavelength value of the reflected or transmitted light from the biosensor, while an increase in the wavelength corresponds to an increase in molecular absorption. A tunable laser light source may generate the collimated white light and a tunable filter may receive the reflected or transmitted light and pass the light to a photodiode sensor. The photodiode sensor then quantifies an amount of the light reflected or transmitted through the tunable filter as a function of the tuning voltage of the tunable filter.

Abstract: Apparatus and method of exposing a chemical, biological or biochemical sample to radiation. A sample in liquid or vapour phase is segmented and conveyed along a sample path. At least one generator or source for generating electromagnetic radiation is directed at the sample and at least one of reflected, emitted and transmitted radiation is measured at least one point along the sample path. In one embodiment, the sample is a luminescent culture produced by a continuous culture system.

Abstract: An optical assay apparatus having an optical filter, an optical sensor with a light ray redirection portion and an assay sensing portion, and a filter to block certain wavelengths of excitation light rays and to pass certain wavelengths of signal recovery light rays from the optical sensor. A method for performing an assay that includes providing at least one assay station, moving the optical sensor into position over a respective fluid in at least one assay station, immersing the assay sensing portion in the respective fluid, and removing the assay sensing portion from the respective fluid.

Abstract: A microfluidic optical sensor utilizes at least one subwavelength nanowire or nanoribbon waveguide coupled to a fluidic structure having at least one nanofluidic channel through which one or more molecular species are conveyed. In response to optical pumping (e.g., a laser source) the waveguide optically interrogates nearby molecular species retained within said fluidic structure to detect chemical species in response to optical characterization of small (on the order of sub-picoliter) volumes of solution. Characterization is performed in response to evanescent wave sensing. In one aspect, optical characterization is selected from the group of optical characterizations consisting of absorbance, fluorescence and surface enhanced Raman spectroscopy (SERS).

Abstract: An optical reader system is described herein that uses a scanned optical beam to interrogate a biosensor to determine if a biomolecular binding event occurred on a surface of the biosensor. In one embodiment, the optical reader system includes a light source, a detector and a processor (e.g., computer, DSP). The light source outputs an optical beam which is scanned across a moving biosensor and while this is happening the detector collects the optical beam which is reflected from the biosensor. The computer processes the collected optical beam and records the resulting raw spectral or angle data which is a function of a position (and possibly time) on the biosensor. The processor can then analyze the raw data to create a spatial map of resonant wavelength (peak position) or resonant angle which indicates whether or not a biomolecular binding event occurred on the biosensor. Several other uses of the raw data are also described herein.

Abstract: A variety of characteristics of body fluid may be measured by introducing a sample to a textured surface on optical material such as waveguides and sheets. The textured surface presents a field of elongated projections which are spaced apart to exclude certain components of the body fluid sample from entering into the spaces between the projections, while permitting other parts of the body fluid sample which contains the analyte to enter into those spaces. The analyte contacts a chemistry on the surface which is sensitive to the analyte, whereupon the analyte and the analyte-sensitive chemistry interact in a manner that is optically detectable. The optical material is packaged in suitable structures such as elongated cylinders, flat test strips, and sheets. A structure containing the optical material is mounted on a detector, which both illuminates the optical material and detects and analyzes the light that returns from the textured surface.

Abstract: A sample detection device includes a disk substrate which allows a light beam to be transmitted, and the substrate has flow paths each of which allows polymers to be injected therein, wherein the substrate further includes a guiding groove, provided in a perpendicular direction with respect to a longitudinal direction of each flow path, along which the light beam for detecting polymers scans. According to the sample detection device, it is possible to efficiently detect many kinds of polymers in accordance with respective separation rates of the polymers.

Abstract: A method for using a double resonance effect within a grating-coupled waveguide (GCW) sensor, as generated from a light beam with a given span of wavelengths or angles, is provided. The method can be used for label-independent detection of biological and chemical agents, to interrogate biological-binding events or chemical reactions within a sensing region at increased sensitivity, and with decreased sensitivity to environmental perturbations. Also described is an optical interrogation system incorporating the method.

Abstract: Methods and compositions are provided for detecting biomolecular interactions. The use of labels is not required and the methods can be performed in a high-throughput manner. The invention also provides optical devices useful as narrow band filters.

Abstract: An apparatus and non-invasive method of measuring oxygen by exciting a luminescent compound disposed in a container and then measuring the intensity of the light emitted by the excited luminescent compound as it relaxes to the ground state. A plot of emission intensity as a function of time results in an exponential decay curve the area of which is inversely proportional to the oxygen concentration. The oxygen concentration can be determined over a wide temperature range by measuring the temperature of the container and the emission intensity and then applying the following equation: [O2]=(ATa(T)2+BTa(T)+CTa)(tau)2+(ATb(T)2+BTb(T)+CTb)(tau)+(ATc(T)2+BTc(T)+CTc) T is the measured temperature; tau is the area of the exponential decay curve; and ATa, BTa, CTa, ATb, BTb, CTb, ATc, BTc, and CTc are coefficients that are specific to the luminescent compound being examined.

Abstract: It is an object of the present invention to provide a biosensor on which a large amount of protein can be immobilized and nonspecific adsorption is less likely to occur with the use of a SAM compound having high water solubility and good performance in terms of supply. The present invention provides a biosensor comprising a substrate on which a hydrophilic polymer having a reactive group capable of binding to a physiologically active substance is immobilized via a compound represented by the following formula (1), said compound at a concentration of 1 mM being dissolved in water at 25° C.: X-L-Y??(1) wherein X represents a group capable of binding to metal, L represents a linking group, and Y represents a functional group to which the hydrophilic polymer is bound.

Abstract: It is an object of the present invention to provide a method for carrying out on a same biosensor both of the measurement of the amount of a physiologically active substance immobilized on a biosensor substrate and the measurement of the biological activity of the above physiologically active substance, thereby analyzing the interaction of a substance with the above physiologically active substance that maintains its activity. The present invention provides a measurement method using a biosensor substrate, wherein both the amount of a physiologically active substance immobilized on the substrate and the biological activity of the physiologically active substance immobilized on the substrate are measured on said same biosensor substrate.

Abstract: The present invention relates to a method for analysing a cell sample for cell surface-bound or intracellularly bound analytes by providing an array of immobilised specific binding agents for a set of different ligands, where each ligand is specific to a respective cell surface-bound or intracellularly bound analyte, and using the array and the set of ligands in an inhibition type or a direct type assay format to determine cell surface-bound or intracellularly bound analytes in the cell sample. The invention also relates to assay kits for cell characterization.

Abstract: The present invention relates to novel methods for the diagnosis of Helicobacter pylori infection. Specifically, the present invention relates to novel non-invasive methods for the detection of the presence or absence of a Helicobacter pylori antigen or a metabolite produced by the bacterium in a biological sample with a biosensor-based measurement. The present invention also related to the use of a biosensor containing specific antibodies against H. pylori or antigen-binding fragments thereof immobilized thereto together with biomolecule-repellent polymers preventing the non-specific binding. The invention also relates to test kits useful in the methods.

Abstract: An assay element is described including recognition ligands bound to a film on a single mode planar optical waveguide, the film from the group of a membrane, a polymerized bilayer membrane, and a self-assembled monolayer containing polyethylene glycol or polypropylene glycol groups therein and an assay process for detecting the presence of a biological target is described including injecting a biological target-containing sample into a sensor cell including the assay element, with the recognition ligands adapted for binding to selected biological targets, maintaining the sample within the sensor cell for time sufficient for binding to occur between selected biological targets within the sample and the recognition ligands, injecting a solution including a reporter ligand into the sensor cell; and, interrogating the sample within the sensor cell with excitation light from the waveguide, the excitation light provided by an evanescent field of the single mode penetrating into the biological target-containing samp

Abstract: An assay element is described including recognition ligands adapted for binding to carcinoembryonic antigen (CEA) bound to a film on a single mode planar optical waveguide, the film from the group of a membrane, a polymerized bilayer membrane, and a self-assembled monolayer containing polyethylene glycol or polypropylene glycol groups therein and an assay process for detecting the presence of CEA is described including injecting a possible CEA-containing sample into a sensor cell including the assay element, maintaining the sample within the sensor cell for time sufficient for binding to occur between CEA present within the sample and the recognition ligands, injecting a solution including a reporter ligand into the sensor cell; and, interrogating the sample within the sensor cell with excitation light from the waveguide, the excitation light provided by an evanescent field of the single mode penetrating into the biological target-containing sample to a distance of less than about 200 nanometers from the wave

Abstract: A composite waveguide for evanescent sensing in fluorescent binding assays comprising a substrate layer having one or more thin-film waveguide channels deposited thereon. Binding molecules having the property of binding with specificity to an analyte are immobilized on the surface of the thin-film channels. In preferred embodiments, the composite waveguide includes integral light input coupling means adapted to the thin-film channels. Light coupling means may include a grating etched into the substrate prior to deposition of the thin film, or a waveguide coupler affixed to the upper surface of the thin film. The waveguide coupler has an input waveguide of high refractive index which receives the laser light through one end, propagating it by total internal reflection. Propagated light is coupled evanescently into the thin film across a spacer layer of precise thickness with a lower index of refraction than that of the input waveguide or the thin-film waveguide.