Abstract:
A particulate detector (10) comprises a radiation source (12) arranged to emit radiation in at least first and second predetermined wavebands towards a sampling region (18) suspected of containing particulates, and a detection element (14), shielded from the radiation source (12), and arranged to detect radiation from the sampling region (18) at least first and second instances. The radiation source (12) is such that the emissions in the wavebands temporarily overlap. The detector is such that, at the instances at which the radiation is detected, the relative contributions from the emissions in each predetermined waveband are distinguishable, thereby allowing characteristics of the particulates to be determined. The radiation source (12) may comprise a light emitting diode (24).
Abstract:
A method and apparatus for detecting pathogens and particles in a fluid in which particle size and intrinsic fluorescence of a simple particle is determined, comprising a sample cell; a light source on one side of the sample cell for sending a focused beam of light through the sample, whereby portions of the beam of light are scattered at various angles by particles of various sizes present in the sample area; a particle size detector positioned in the light path for detecting a portion of forward scattered light; a pair of fluorescence detectors positioned off axis from the beam of light; and a pair of elliptical mirrors positioned such that an intersection of the incoming particle stream and the light beam are at one foci of each ellipsoid, and one of said pair of fluorescence detectors lies at the other foci.
Abstract:
A particulate detector (10) comprises a radiation source (12) arranged to emit radiation in at least first and second predetermined wavebands towards a sampling region (18) suspected of containing particulates, and a detection element (14), shielded from the radiation source (12), and arranged to detect radiation from the sampling region (18) at at least first and second instances. The radiation source (12) is such that the emissions in the wavebands temporarily overlap. The detector is such that, at the instances at which the radiation is detected, the relative contributions from the emissions in each predetermined waveband are distinguishable, thereby allowing characteristics of the particulates to be determined. The radiation source (12) may comprise a light emitting diode (24).
Abstract:
A method of producing a surface enhanced Raman scattering spectrum which is useful for certain types of assays, in particular proximity assays. The method includes providing two SERS-active nanoparticles. The first SERS-active nanoparticle will absorb a photon at a first wavelength and emit a Raman-shifted photon at a second wavelength. The second SERS-active nanoparticle will absorb a photon at the second wavelength and emit a Raman-shifted photon at a third wavelength. Accordingly, when the first and second SERS-active nanoparticles are proximate to one another and the first SERS-active nanoparticle is illuminated at the first wavelength a Raman-shifted photon at the second wavelength may be emitted. This photon can be absorbed by the second SERS-active nanoparticle causing detectable emission of a second Raman-shifted photon at the third wavelength. Various assays may be designed based upon the above. Proximity assays using two SERS-active nanoparticles will have advantageous background signal characteristics.
Abstract:
Dispositif de détection de la fluorescence émise par des éléments chromophores contenus dans des puits d'une plaque à puits multiples, ce dispositif comprenant des moyens intégrés (54,56) dans les fonds transparents des puits (12) de la plaque (10) pour limiter la longueur de pénétration dans les puits d'un faisceau lumineux d'excitation des éléments chromophores (38) fixés sur les fonds (14) des puits.
Abstract:
The Laser Induced Fluorescence Attenuation Spectroscopy method and apparatus include a source (311) adapted to emit modulated radiation that is directed at a sample volume in a sample (314) to produce return light from the sample, a first sensor (321), displaced by a first distance from the sample volume for monitoring the return light and generating a first signal indicative of the intensity of return light, a second sensor (322) displaced by a second distance from the sample volume for monitoring the return light and generating a second signal indicative of the intensity of return light, and a processor (323) adapted to process the first and second signals so as to determine the modulation of the sample. Methods and devices are well-suited for determining the wavelength-dependent attenuation of a sample and using the attenuation to restore the intrinsic laser induced fluorescence thereof, and can be used to determine the ischemic or hypoxic condition of biological tissue.
Abstract:
The present invention relates to an apparatus (100) for inspecting a stream of matter (10) comprising: a first and a second light source (101;102) for emitting a first and a second light beam (111;112); a first and a second detector (131;132); a first scanning element (151) adapted to redirect the detection area (137) of the second detector from side to side across said stream, and a beam splitting element (140) arranged to receive said first and second light beams (111), after they have been reflected against said matter, wherein said beam splitting element (140) is adapted to guide said reflected first light beam (111) towards said first detector (131) and to guide said reflected second light beam (112) towards said second detector (132).
Abstract:
A side illuminated multi point multi parameter optical fiber sensor that requires no sensitive coating is provided. This sensor comprises an optical fiber having at least one removed cladding section as the sensitive region, at least one probing light source that side illuminates the fiber, a power supply, a detector, a signal processor and a display. The sensitive optical fiber is optically affected by the presence of a measurand medium that can fluoresce, phosphoresce, absorb and/or scatter the probing light. This probing light is guided by the fiber core towards a detector which measures the light intensity and this light intensity is correlated with a measurand.
Abstract:
The invention relates to a light source for irradiating molecules present in a detection volume with one or more selected wavelengths of light and directing the fluorescence, absorbance, transmittance, scattering onto one or more detectors. Molecular interactions with the light allow for the identification and quantitation of participating chemical moieties in reactions utilizing physical or chemical tags, most typically fluorescent and chromophore labels. The invention can also use the light source to separately and simultaneously irradiate a plurality of capillaries or other flow confining structures with one or more selected wavelengths of light and separately and simultaneously detect fluorescence produced within the capillaries or other flow confining structures. In various embodiments, the flow confining structures can allow separation or transportation of molecules and include capillary, micro bore and milli bore flow systems. The capillaries are used to separate molecules that are chemically tagged with appropriate fluorescent or chromophore groups.
Abstract:
Methods and devices for Laser Induced Fluorescence Attenuation (LIFAS) Spectroscopy, including, in particular, methods and devices for the detection of ischemia and hypoxia in biological tissue. The LIFAS method and apparatus preferably include a source adapted to emit radiation that is directed at a sample volume in a sample to produce return light from the sample, such return light including modulated return light resulting from modulation by the sample, a first sensor, displaced by a first distance from the sample volume for monitoring the return light and generating a first signal indicative of the intensity of return light, a second sensor, displaced by a second distance from the sample volume for monitoring the return light and generating a second signal indicative of the intensity of return light, and a processor associated with the first sensor and the second sensor and adapted to process the first and second signals so as to determine the modulation of the sample. The methods and devices of the inventions are particularly well-suited for determining the wavelength-dependent attenuation of a sample and using the attenuation to restore the intrinsic laser induced fluorescence of the sample. In turn, the attenuation and intrinsic laser induced fluorescence can be used to determine a characteristic of interest, such as the ischemic or hypoxic condition of biological tissue.