Method and apparatus for assay based on light diffraction
First Claim
1. An apparatus for detection of analytes in a medium using diffraction of light, comprising:
- a source of illumination;
a sensing element including a diffractive optic element having analyte-specific receptors bound to a surface of said diffractive optic element for binding selected analytes, the analyte-specific receptors being laid out on said surface in a pre-selected pattern such that when analytes are present in the medium they bind to said analyte-specific receptors, said pre-selected pattern being configured so that under illumination by a beam of light a diffraction pattern is produced having at least one diffraction spot spaced from said beam of light with a sufficient amount of intensity of said diffraction pattern being located at said at least one diffraction spot to indicate presence of analytes bound to said analyte-specific receptors, said pre-selected pattern excluding said analyte-specific receptors arrayed in parallel straight lines of substantially equal width spaced evenly from each other, or in a periodic array of circles, said source of illumination being positioned so as to illuminate said diffractive optic element, wherein said diffractive optic element is a diffractive optic beam splitter, which produces a pre-selected number of light beams of approximately equal intensities when illuminated by a single incident beam of light;
detection means positioned with respect to said sensing element to detect light diffracted from said diffractive optic element; and
processing means for analysing said diffracted light for presence of a diffraction image representative of binding of one or more analytes with their analyte-specific receptors and identifying from said diffraction pattern analytes present in said medium.
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Abstract
The present invention relates to a method and apparatus for detecting analytes in a medium, and more particularly the present invention relates to an assay based on light diffraction which appears or changes upon the binding of analytes to their specific receptors laid out in patterns on a substrate, which has high sensitivity due to the appropriate choice of such patterns. The present invention is based on the principle that the pattern of recognition elements, which gives rise to the diffraction of the incident light in a diffraction-based assay, can be chosen in such a way so as to facilitate detection, and to enhance the signal to be detected compared to known gratings such as parallel straight lines. In one aspect the substrate itself has a surface topography designed to enhance the diffraction pattern signals. In another aspect the substrate is a diffractive optic element having the analyte-specific receptors affixed to the optic element. In another aspect the diffractive optic element is used as a master stamp for producing patterns of analyte-specific receptors which give the signal enhancements.
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Citations
19 Claims
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1. An apparatus for detection of analytes in a medium using diffraction of light, comprising:
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a source of illumination; a sensing element including a diffractive optic element having analyte-specific receptors bound to a surface of said diffractive optic element for binding selected analytes, the analyte-specific receptors being laid out on said surface in a pre-selected pattern such that when analytes are present in the medium they bind to said analyte-specific receptors, said pre-selected pattern being configured so that under illumination by a beam of light a diffraction pattern is produced having at least one diffraction spot spaced from said beam of light with a sufficient amount of intensity of said diffraction pattern being located at said at least one diffraction spot to indicate presence of analytes bound to said analyte-specific receptors, said pre-selected pattern excluding said analyte-specific receptors arrayed in parallel straight lines of substantially equal width spaced evenly from each other, or in a periodic array of circles, said source of illumination being positioned so as to illuminate said diffractive optic element, wherein said diffractive optic element is a diffractive optic beam splitter, which produces a pre-selected number of light beams of approximately equal intensities when illuminated by a single incident beam of light; detection means positioned with respect to said sensing element to detect light diffracted from said diffractive optic element; and processing means for analysing said diffracted light for presence of a diffraction image representative of binding of one or more analytes with their analyte-specific receptors and identifying from said diffraction pattern analytes present in said medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification