Dielectric waveguide sensors and their use in immunoassays

Claim 2

A dielectric waveguide for use in fluorescence assays of an analyte in a fluid, comprising: (a) a core having an index of refraction (N 1 ) and an opening in the core; (b) a cladding about the core having an index of refraction (N 2 ) which is less than N 1 ; and (c) a reactant coating about the opening of the core which comprises an analyte-binder, wherein the core is transmissive to radiation which can excite fluorescence of a fluorescent tag and transmissive to fluorescent radiation from the fluorescent tag.

Claim 3

The dielectric waveguide of claim 1 wherein the core has hollow opening throughout its length.

Claim 4

The dielectric waveguide of claim 1 wherein the waveguide has a fiber shape with two ends, one of which has a mirror coating.

Claim 5

The dielectric waveguide of claim 1 wherein the waveguide has a fiber shape and a mirror coating on cladding.

Claim 6

The dielectric waveguide of claim 1 wherein the reactant coating is an immobilized antibody.

Claim 7

The dielectric waveguide of claim 1 wherein the reactant coating is an immobilized antigen.

Claim 8

The dielectric waveguide of claim 1 wherein the reactant coating is an enzyme.

Claim 9

A method of spectrophotometrically assaying an analyte in a fluid comprising: (a) contacting the dielectric waveguide of claim 1 with the fluid for a time sufficient for the analyte and the analyte-binder to be able to interact; (b) propagating radiation down the waveguide core so as to irradiate the interacting analyte and analyte-binder in the presence of a fluorescent tag; (c) detecting the fluorescence radiation resulting from the irradiation of the analyte interaction by monitoring the waveguide.

Claim 10

An improved apparatus for spectrophotometrically assaying an analyte in a fluid having a radiation source and a means for detecting fluorescence radiation, the improvement comprising: (a) the dielectric waveguide of claim 1; (b) a means for guiding radiation from the source, to the waveguide such that it is propagated down the waveguide; and (c) a means for guiding the fluorescence signal radiation from the waveguide to the detection means.

Claim 11

A multi-element dielectric waveguide for use in fluorescence assays of an analyte in a fluid comprising: (a) a support fiber having an index of refraction (N A ) and an opening therethrough; (b) a second core fiber axially positioned within the support fiber opening and having an index of refraction (N B ); (c) a means for maintaining the axial position of the core fiber within the support fiber; and (d) a reactant coating on the support fiber or on the core fiber which comprises an analyte-binder, wherein the support fiber and the core fiber are transmissive to radiation which can excite fluorescence of a fluorescent tag and transmissive to fluorescent radiation from the fluorescent tag.

Claim 12

A multi-element dielectric waveguide for use in fluorescence assays of an analyte in a fluid comprising: (a) a support fiber having an index of refraction (N A ) and an opening therethrough; (b) a second core fiber axially positioned within the support fiber opening and having an index of refraction (N B ); (c) a means for maintaining the axial position of the core fiber within the support fiber; and (d) a reactant coating on the support fiber or on the core fiber which comprises an analyte-binder, wherein the support fiber and the core fiber are transmissive to radiation which can excite fluorescence of a fluorescent tag and transmissive to fluorescent radiation from the fluorescent tag.

Claim 13

The dielectric waveguide of claim 10 wherein N B is greater than N A .

Claim 14

The dielectric waveguide of claim 10 wherein N B is equal to N A .

Claim 15

The dielectric waveguide of claim 10 wherein N B is less than N A .

Claim 16

The dielectric waveguide of claim 10 wherein a mirror coating is placed about the outside of support fiber.

Claim 17

The dielectric wavegude of claim 10 wherein the core fiber has a cladding on the outside with an index of refraction N C which is greater than N B .

Claim 18

The dielectric waveguide of claim 10 wherein the core fiber has a reactant coating which, in the presence of electromagnetic radiation, interacts with the analyte to form a signal radiation.

Claim 19

The dielectric waveguide of claim 10 wherein the support fiber has a reactant coating which, in the presence of electromagnetic radiation, interacts with the analyte to form a signal radiation.

Claim 20

A method of spectrophotometrically assaying an analyte in a fluid comprising: (a) contacting the dielectric waveguide of claim 10 with the fluid for a time sufficient for the analyte and the analyte-binder to be able to interact; (b) propagating radiation down the core fiber so as to irradiate the combination of analyte and analyte-binder in the presence of a fluorescent tag; (c) detecting the fluorescence radiation from the irradiated analyte and analyte-binder interaction by monitoring the waveguide.

Claim 21

A method of spectrophotometrically assaying an analyte in a fluid comprising: (a) contacting the dielectric waveguide of claim 10 with the fluid for a time sufficient for the analyte and the analyte-binder to be able to interact; (b) propagating radiation down the support fiber so as to irradiate the combination of analyte and analyte-binder in the presence of a fluorescent tag; (c) detecting the fluorescence radiation from the irradiated analyte and analyte-binder interaction by monitoring the waveguide.

Claim 22

A method of spectrophotometrically assaying an analyte in a fluid comprising: (a) contacting the dielectric waveguide of claim 10 with the fluid for a time sufficient for the analyte and the analyte-binder to be able to interact; (b) propagating radiation within the fluid so as to irradiate the combination of analyte and analyte-binder in the presence of a fluorescent tag; (c) detecting the fluorescence radiation from the irradiated analyte and reactant interaction by monitoring the waveguide.

Claim 23

A dielectric waveguide for use in fluorescence assays of an analyte in a fluid comprising: (a) a core having an index of refraction (N X ) and an opening therethrough; (b) a series of claddings about the core having alternating indices of refraction (N 2 ) and (N 1 ) where N 2 is less than N 1 and only one of either can equal N X , and of such a number and configuration so as to enable radiation which can excite the fluorescence of a fluorescent tag to propagate within the core opening and to enable the fluorescent radiation from the fluorescent tag to propagate within the core opening and; (c) a reactant coating on the core surface which comprises an analyte-binder.

Claim 24

A dielectric waveguide for use in fluorescence assays of an analyte in a fluid comprising: (a) a core having an index of refraction (N X ) and an opening therethrough; (b) a series of claddings about the core having alternating indices of refraction (N 2 ) and (N 1 ) where N 2 is less than N 1 and only one of either can equal N X , and of such a number and configuration so as to enable radiation which can excite the fluorescence of a fluorescent tag to propagate within the core opening and to enable the fluorescent radiation from the fluorescent tag to propagate within the core opening and; (c) a reactant coating on the core surface which comprises an analyte-binder.

Claim 25

A method of spectrophotometrically assaying an analyte comprising: (a) contacting the dielectric waveguide of claim 21 with the fluid for a time sufficient for the analyte and the analyte-binnder to interact; (b) propagating radiation down the waveguide so as to irradiate the combination of analyte and analyte-binder in the presence of a fluorescent tag; and (c) detecting the fluorescence radiation resulting from the irradiation of the analyte and analyte-binder interaction by monitoring the fluid.