Patent ID: 6974673

Claim:
An optical biosensor, comprising: a hollow optical waveguide having a light-input end, a light-output end, and a wall with a thickness and an inner surface; a second optical waveguide having a light-input end, a light-output end, and a length with an outer surface disposed within the hollow optical waveguide thereby creating a cavity between the inner surface of the hollow optical waveguide and the outer surface of the second optical waveguide; a source of optical energy directed into one or both of the light-input ends of the hollow and second optical waveguides, establishing an evanescent field that extends into the cavity from one or both of the inner surface of the hollow optical waveguide and the outer surface of the second optical waveguide; a first optoelectric detector operative to receive light from the light-output end of the hollow optical waveguide and convert the light received into a first electrical signal; a second optoelectric detector operative to receive light from the light-output end of the second optical waveguide and convert the light received into a second electrical signal; a first biomolecular constituent attached to one or both of the inner wall of the hollow optical waveguide and the outer surface of the second optical waveguide, such that the first biomolecular binding partner is substantially within the evanescent field, if present; and a fluid within the cavity which may contain a second biomolecular constituent, the second constituent having a binding affinity to the first biomolecular constituent, such that if binding occurs between the biomolecular constituents, a representative change occurs in the light emerging from one or both of the output ends of the hollow and second optical waveguides and the electrical signals from the optoelectric detectors.