Method and apparatus for improved light collection

Abstract

An apparatus for enhancing the collection of optical signals comprises a waveguide, which comprises a structure in a channel adapted for the flow of assay fluid. In one embodiment, fluorophore is coupled to a surface of the structure, where the fluorophore has a receptor for an analyte (ligand) in the assay fluid and the structure is adapted to transmit optical signals from the fluorophore to a detector that is adapted to detect optical signals from the fluorophore coupled to the waveguide.

1 . An apparatus for enhancing the collection of optical signals comprising: 
 a waveguide, said waveguide comprising at least one aperture in a conduit adapted to channel the flow of an assay fluid;    a reflective coating positioned on said conduit coincident with said opening, said coating comprising at least one dielectric layer; and    a detector adapted to detect optical signals from at least one fluorophore coupled to at least one analyte in said assay fluid, said detector positioned coincident with said aperture.    
   
   
       2 . The apparatus according to  claim 1 , wherein: 
 said reflective coating comprises layers of Ta 2 O 5  alternating with SiO 2 .    
   
   
       3 . The apparatus according to  claim 2 , wherein: 
 said layer in contact with said assay fluid comprises SiO 2 .    
   
   
       4 . The apparatus according to  claim 3 , wherein: 
 said layer in contact with said assay fluid comprises said fluorophore.    
   
   
       5 . The apparatus according to  claim 1 , wherein: 
 said reflective coating comprises a single reflective layer comprising at least one highly reflective material chosen from gold and silver.    
   
   
       6 . The apparatus according to  claim 5 , wherein: 
 said single reflective layer comprises said fluorophore.    
   
   
       7 . An apparatus for enhancing the collecting of optical signals comprising: 
 a waveguide, said waveguide comprising at least one aperture in a conduit adapted to channel the flow of an assay fluid;    at least one additive to alter the refractive index of said assay fluid positioned within said conduit coincident with said aperture; and    a detector adapted to detect optical signals from at least one fluorophore coupled to at least one analyte in said assay fluid, said detector positioned coincident with said aperture.    
   
   
       8 . The apparatus according to  claim 7 , wherein: 
 said additive comprises at least one material chosen from gold, polyethylene glycol, polysulfone, and dye.    
   
   
       9 . The apparatus according to  claim 7 , wherein: 
 said additive comprises gold, said gold coupled to said fluorophore.    
   
   
       10 . A method for enhancing an optical signal comprising: 
 receiving said optical signal, wherein said optical signal is generated from a fluorophore created by an optically tagged analyte;    directing said optical signal using a waveguide, the waveguide having a structure, said structure adapted to channel flow of an assay fluid; and    detecting said optical signal.    
   
   
       11 . The method as recited in  claim 10 , wherein the structure further comprises: 
 at least two fingers adapted to protrude into an assay fluid flow, wherein said assay fluid flows between said fingers.    
   
   
       12 . The method as recited in  claim 11 , wherein said fingers have a ratio of thickness to length of 1:100 to 1:1000.  
   
   
       13 . The method as recited in  claim 11 , wherein the structure comprises at least two pores adapted to channel said assay fluid flow through said pores, said pores having a diameter less than a wavelength of the optical signal transmitted through said structure.  
   
   
       14 . The method as recited in  claim 10 , wherein said structure comprises at east two recessions etched into said waveguide, said recessions adapted to channel said assay fluid flow.