EP0326291A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Biological sensors
Assignee: GE Healthcare Ltd
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Filing: 1989-01-20
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Granted: —
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Expires: 2009-01-20
Abstract
Abstract A biological sensor which utilises the phenomenon of surface plasmon resonance to detect the refractive index change which occurs when two components - for example antibody and corresponding antigen - react with one another. Surface plasmon resonance takes place at the sloping exit surface of an optical waveguide such as a fibre optic 23. The input end of fibre optic 12 is connected to a light source 12. A layer 25 of metal is applied to the sloping exit surface so as to cause total internal reflection of the light proceeding down the fibre optic. Reflected light is detected by a detector 13. A sensitive, for example antibody, layer 26 is applied to the metal layer. Sample (not shown) reacts with layer 26 in such a way that the refractive index changes. Provided conditions are correct, this variation in refractive index can be monitored in detector 13 by virtue of the surface plasmon resonance which occurs in the area of total internal reflection.
Inventors
- 👤 Martin Francis Finlan
- 👤 Richard Paul Harvey
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 12:24
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54366; G01N33/54373; G01N21/00; G01N21/17; G01N21/55; G01N21/552; G01N21/553
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
162 words
A sensor for use in biological, biochemical or chemical testing, said sensor comprising an optical waveguide having an input end and an output end, a source of electromagnetic radiation whose output is applied to the input end of said optical waveguide, and wherein said output end of the optical waveguide is cut off at an angle to its axis to provide a sloping end face, means for monitoring the radiation from said source which is internally reflected at said face, a layer of metallic material applied to said sloping face, a layer of sensitive material applied to the metallic layer, and means for introducing onto the sensitive layer so as to react therewith a sample to be analysed, the arrangement being such that the radiation incident at said face of the optical waveguide causes surface plasmon resonance to occur, the characteristics of which resonance, as detected by said monitoring means, is dependent upon the reaction between the sample and the sensitive layer.
Claim 2
Dependent Claim
162 words
A sensor for use in biological, biochemical or chemical testing, said sensor comprising an optical waveguide having an input end and an output end, a source of electromagnetic radiation whose output is applied to the input end of said optical waveguide, and wherein said output end of the optical waveguide is cut off at an angle to its axis to provide a sloping end face, means for monitoring the radiation from said source which is internally reflected at said face, a layer of metallic material applied to said sloping face, a layer of sensitive material applied to the metallic layer, and means for introducing onto the sensitive layer so as to react therewith a sample to be analysed, the arrangement being such that the radiation incident at said face of the optical waveguide causes surface plasmon resonance to occur, the characteristics of which resonance, as detected by said monitoring means, is dependent upon the reaction between the sample and the sensitive layer.
Claim 3
Dependent Claim
37 words
A sensor as claimed in Claim 1 wherein said optical waveguide is formed of solid material transparent to the radiation in use, and along which the radiation propagates by means of internal reflections off its internal surfaces.
Claim 4
Dependent Claim
15 words
A sensor as claimed in Claim 2 wherein the optical waveguide is a fibre optic.
Claim 5
Dependent Claim
23 words
A sensor as claimed in Claim 2 wherein the optical waveguide is a rectangular slab of transparent material, such as a microscope slide.
Claim 6
Dependent Claim
36 words
A sensor as claimed in any one of Claims 2 to 4 wherein the material of the waveguide is clad with a material having a refractive index which is lower than that of the waveguide material.
Claim 7
Dependent Claim
31 words
A sensor as claimed in any one of Claims 2 to 5 wherein the material of the waveguide, and its cladding (if any) is embedded in a block of transparent material.
Claim 8
Dependent Claim
26 words
A sensor as claimed in Claim 6 wherein the material of said block has a refractive index which is lower than that of the waveguide material.
Claim 9
Dependent Claim
56 words
A sensor as claimed in either one of Claims 6 or 7 wherein said block is arranged to receive light internally reflected off said sloping end face and passing out of said waveguide medium, and wherein said block has an output face through which such internally reflected light passes, to be incident on said monitoring means.
Claim 10
Dependent Claim
32 words
A sensor as claimed in Claim 8 wherein said output face is curved, having a centre of curvature coincident with the point at which the radiation is incident on said end face.
Claim 11
Dependent Claim
27 words
A sensor as claimed in any one of the preceding claims further including focussing means for focussing the radiation from the source onto the sloping end face.
Claim 12
Dependent Claim
30 words
A sensor as claimed in any one of Claims 1 to 9 further including focussing means for focussing the radiation from said source onto the input of the optical waveguide.
Claim 13
Dependent Claim
38 words
A sensor as claimed in Claim 11 wherein the optical waveguide is of circular cross section, further including means for forming the radiation from the source into a series of separate radially spaced, coaxial beams of annular section.
Claim 14
Dependent Claim
34 words
A sensor as claimed in Claim 11 wherein the optical waveguide is of rectangular cross section, further including means for forming the radiation from the source into a series of separate spaced planar beams.
Claim 15
Dependent Claim
38 words
A sensor as claimed in either one of Claims 12 or 13 wherein the axial length of the optical waveguide is such that all of the separate input beams come to a common focus at the end face.
Claim 16
Dependent Claim
50 words
A sensor as claimed in any one of the preceding claims including one or more further optical waveguides illuminated by a common source of radiation or by respective separate sources of radiation to enable testing of multiple analytes in a single sample, or multiple samples, to be carried out simultaneously.
References Cited (Backward Citations)
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