Waveguide sensor with input and reflecting gratings and its use in immunoassay
First Claim
1. A planar waveguide comprising an input grating structure constructed so as to couple excitation radiation into the waveguide so as to propagate therethrough, a reflecting grating structure spacially disposed from said input grating structure and constructed so as to reflect said excitation radiation propagating within the waveguide, and a transduction region located between said input grating structure and said reflecting grating structure, whereby during use said excitation radiation traverses said transduction region at least twice.
2 Assignments
0 Petitions
Accused Products
Abstract
Waveguides suitable for use in optical assay techniques are described, as well as methods of assay employing such waveguides. The waveguide comprises an input grating structure to couple excitation radiation into the waveguide, a reflecting grating structure to reflect the excitation radiation propagating within the waveguide, and a transduction region located between the two grating structures, whereby during use the excitation radiation traverses the transduction region at least twice.
136 Citations
18 Claims
- 1. A planar waveguide comprising an input grating structure constructed so as to couple excitation radiation into the waveguide so as to propagate therethrough, a reflecting grating structure spacially disposed from said input grating structure and constructed so as to reflect said excitation radiation propagating within the waveguide, and a transduction region located between said input grating structure and said reflecting grating structure, whereby during use said excitation radiation traverses said transduction region at least twice.
- 8. A waveguide sensor useful for the optical assay of a chemical, biological or biochemical substance, said waveguide sensor comprising a planar waveguide comprising an input grating structure constructed so as to couple excitation radiation into the waveguide so as to propagate therethrough, a reflecting grating structure spacially disposed from said input grating structure and constructed so as to reflect said excitation radiation propagating within the waveguide, and a transduction region located between said input grating structure and said reflecting grating structure, said transduction region having immobilized thereon, directly or indirectly, a reagent constructed so as to interact with another assay reagent during use so as to produce an optically measurable result, whereby during use said excitation radiation traverses said transduction region at least twice.
-
13. In a method of assaying for a ligand in a sample which method comprises incubating the sample with components (a) a specific binding partner for the ligand and (b) a ligand analogue or a specific binding partner for the ligand, one of said components being immobilised on the surface of a transduction region of a planar waveguide and the other of said components carrying a fluorophore, said fluorophore becoming bound to said transduction region as a result of complex formation;
- propagating excitation radiation in the waveguide so as to cause said bound fluorophore to emit signal radiation into the waveguide; and
measuring said signal radiation to determine the presence or amount of said ligand;
the improvement wherein said waveguide comprises an input grating structure constructed so as to couple excitation radiation into the waveguide so as to propagate therethrough, a reflecting grating structure spacially disposed from said input grating structure and constructed so as to reflect said excitation radiation propagating within the waveguide, and said transduction region being located between said input grating structure and said reflecting grating structure, whereby during said assay said excitation radiation traverses said transduction region at least twice. - View Dependent Claims (14, 15)
- propagating excitation radiation in the waveguide so as to cause said bound fluorophore to emit signal radiation into the waveguide; and
-
16. In a method of assaying for a ligand in a sample which method comprises incubating the sample with components (a) a specific binding partner for the ligand and (b) a ligand analogue or a specific binding partner for the ligand, one of said components being immobilised on the surface of a transduction region of a planar waveguide, the immobilised component or the surface of the transduction region having a fluorophore bound thereto, and the other of said components being such that on complex formation the signal radiation emitted by said fluorophore is quenched;
- propagating excitation radiation into the waveguide so as to cause said fluorophore to emit signal radiation into the waveguide; and
measuring the extent to which said signal radiation is quenched to determine the presence or amount of said ligand;
the improvement wherein said waveguide comprises an input grating structure constructed so as to couple excitation radiation into the waveguide so as to propagate therethrough, a reflecting grating structure spacially disposed from said input grating structure and constructed so as to reflect said excitation radiation propagating within the waveguide, and said transduction region being located between said input grating structure and said reflecting grating structure, whereby during said assay said excitation radiation traverses said transduction region at least twice. - View Dependent Claims (17, 18)
- propagating excitation radiation into the waveguide so as to cause said fluorophore to emit signal radiation into the waveguide; and
Specification