Microporous substrate for use in a disposable bioassay cartridge

Abstract

A microporous substrate for detection of surface bound target analyte molecules includes a microporous substrate material having opposed surfaces and tapered micropores extending through the substrate with the micropores having wider openings on one side of the substrate compared to the other side. The micropores have bound therein analyte specific receptors complementary to the target molecules. When a liquid sample containing the target analyte molecules with optical probes attached to the target molecules is flowed through the substrate, they bind to their complementary analyte specific receptors and emit light. This microporous substrate structure gives an increase in the collection efficiency of light emitted from optical probes when the light is detected by a light detector spaced from the side of the microporous substrate facing the larger micropores openings compared to a light collection efficiency of light emitted from the optical probes when the micropores are straight and not tapered.

1 . A microporous substrate for detection of surface bound target analyte molecules, comprising:
 a microporous substrate material having opposed surfaces and micropores, the micropores having bound therein analyte specific receptors complementary to the target analyte molecules, the micropores having tapered walls extending through a thickness of said microporous substrate in which the micropores are wider near one surface of the microporous substrate compared to a width of the micropores on the opposed surface to increase the collection efficiency of light emitted from optical probes bound to target analyte molecules when the target analyte molecules are captured by the analyte specific receptors which is detected by a light detector spaced from the side of the microporous substrate facing the larger micropore openings compared to a light collection efficiency of light emitted from the optical probes when the micropores are straight and not tapered.   
     
     
         2 . The microporous substrate according to  claim 1 , wherein the micropores are progressively wider near one surface of the microporous substrate. 
     
     
         3 . The microporous substrate according to  claim 1 , wherein the micropores have a rectangular cross section. 
     
     
         4 . The microporous substrate according to  claim 1 , wherein the micropores have a square cross section. 
     
     
         5 . The microporous substrate according to  claim 1 , wherein the micropores have a circular cross section. 
     
     
         6 . The microporous substrate according to  claim 1 , wherein in which tapering of the micropore walls is conical, spherical, or parabolic. 
     
     
         7 . The microporous substrate according to  claim 1 , wherein a micropore dimension on the side opposite the side of the widened micropores are substantially smaller thereby providing structural stability. 
     
     
         8 . The microporous substrate according to  claim 1 , wherein the micropores are of uniform dimensions and morphology. 
     
     
         9 . The microporous substrate according to  claim 1 , further comprising reinforcement ribs to provide structural stability. 
     
     
         10 . The microporous substrate according to  claim 9 , wherein the reinforcement ribs are an integral part of the microporous substrate. 
     
     
         11 . The microporous substrate according to  claim 9 , wherein the reinforcement ribs are separate from the microporous substrate and made in a form of a rigid supporting mesh. 
     
     
         12 . The microporous substrate according to  claim 11 , wherein said microporous substrate is attached to a supporting mesh placed on the surface of said microporous substrate having the smaller micropore openings. 
     
     
         13 . The microporous substrate according to  claim 12 , wherein said microporous substrate is placed between two supporting meshes placed on the opposite sides of said microporous substrate. 
     
     
         14 . The microporous substrate according to  claim 1 , wherein the microporous substrate has a thickness of between 0.15 to about 0.75 mm. 
     
     
         15 . The microporous substrate according to  claim 1 , wherein the tapered surface of a micropore is covered with a reflective coating. 
     
     
         16 . The microporous substrate according to  claim 1 , wherein the microporous substrate is made of silicon. 
     
     
         17 . The microporous substrate according to  claim 1 , wherein the microporous substrate is made of a material that is opaque such that light from one micropore cannot be transmitted to neighboring micropores with the microporous substrate. 
     
     
         18 . The microporous substrate according to  claim 1 , wherein the microporous substrate is generally planar. 
     
     
         19 . A method for manufacturing the microporous substrate according  claim 1 , comprising:
 performing electrochemical etching of silicon to manufacture the microporous substrate.   
     
     
         20 . A method for manufacturing the microporous substrate according  claim 1 , comprising:
 embossing or molding of a plastic material to manufacture the microporous substrate.