Colorimetric sensor

Abstract

Disclosed herein are calorimetric sensor films comprising a reflective layer, polymeric detection layer, and semi-reflective layer. Also disclosed are devices comprising the colorimetric sensor films and methods of making the films and devices.

What is claimed is:  
     
         1 . A colorimetric sensor for measuring one or both of the presence and concentration of an analyte comprising: 
 a substantially continuous reflective layer;    a detection layer over the reflective layer, the detection layer comprising at least one polymer component, said layer being capable of a change in optical thickness upon exposure to said analyte; and    a substantially continuous semi-reflective layer over the detection layer, the semi-reflective layer having an index of refraction different from the index of refraction of the detection layer.    
     
     
         2 . The calorimetric sensor of  claim 1  further comprising a substrate layer under the reflective layer.  
     
     
         3 . The calorimetric sensor of  claim 1  wherein the detection layer comprises a porous material.  
     
     
         4 . The colorimetric sensor of  claim 1  wherein the change in optical thickness of the detection layer is due to a dimensional change of said detection layer.  
     
     
         5 . The colorimetric sensor of  claim 1  wherein the change in optical thickness of the detection layer is due to a change in the index of refraction of said detection layer.  
     
     
         6 . The calorimetric sensor of  claim 1  wherein the change in optical thickness of the detection layer is permanent.  
     
     
         7 . The colorimetric sensor of  claim 1  wherein the change in optical thickness of the detection layer is reversible.  
     
     
         8 . The colorimetric sensor of  claim 1  wherein the detection layer comprises two or more polymer components and wherein the optical thickness of each polymer component will change in the presence of a different analyte.  
     
     
         9 . The sensor of  claim 8  wherein the polymer components are blended.  
     
     
         10 . The sensor of  claim 8  wherein different polymer components comprise different areas of the detection layer.  
     
     
         11 . The colorimetric sensor of  claim 1  wherein the detection layer comprises at least two polymers and wherein the optical thickness of only one polymer will change in the presence of an analyte.  
     
     
         12 . The colorimetric sensor of  claim 11  wherein the at least two polymers are arranged such that a visible pattern will form when the sensor is exposed to the analyte.  
     
     
         13 . The colorimetric sensor of  claim 1  wherein at least one polymer in the detection layer is at least partially crosslinked.  
     
     
         14 . The colorimetric sensor of  claim 1  wherein at least one polymer in the detection layer is selected from the group consisting of polymers or copolymers comprising acrylates and methacrylates.  
     
     
         15 . The calorimetric sensor of  claim 1  wherein at least one polymer in the detection layer is a copolymer.  
     
     
         16 . The colorimetric sensor of  claim 1  wherein one or both of the reflective and semi-reflective layer comprises a metal.  
     
     
         17 . The colorimetric sensor of  claim 1  wherein the semi-reflective layer has a visible light transmittance of about 30 to about 70%.  
     
     
         18 . An array comprising two or more of the calorimetric sensors of  claim 1 .  
     
     
         19 . The array of  claim 18  wherein at least two sensors are on opposite sides of a substrate.  
     
     
         20 . The calorimetric sensor of  claim 1  further comprising molecular receptors in the detection layer.  
     
     
         21 . The colorimetric sensor of  claim 20  wherein the molecular receptors are selected from the group consisting of calixarenes, cyclodextrins, azacrowns, crown ethers, porphyrins, metalloporphrins, peptides, proteins, nucleic acids, and oligonucleotides.  
     
     
         22 . A device comprising the calorimetric sensor of  claim 1  and a light source.  
     
     
         23 . The device of  claim 22  further comprising a photo-detector.  
     
     
         24 . A method of detecting the presence or absence of an analyte comprising 
 providing the calorimetric sensor of  claim 1 ,    providing a light source,    contacting the sensor with a medium that may contain an analyte, and    monitoring the sensor for a change inoptical properties.    
     
     
         25 . The method of  claim 24  wherein a photo-detector is used to monitor the sensor for a change inoptical properties.  
     
     
         26 . The method of  claim 25  wherein the change in optical properties produces a visible change.  
     
     
         27 . The method of  claim 24  wherein the medium is a gas.  
     
     
         28 . The method of  claim 24  wherein the medium is a liquid.  
     
     
         29 . The method of  claim 24  wherein the analyte is a gas.  
     
     
         30 . The method of  claim 24  wherein the analyte is a liquid.  
     
     
         31 . A calorimetric sensor for measuring one or both of the presence and concentration of an analyte comprising: 
 a substantially continuous reflective layer;    a detection layer over the reflective layer, the detection layer comprising at least one polymer component; and    a substantially continuous semi-reflective layer over the detection layer, the semi-reflective layer having an index of refraction different from the index of refraction of the detection layer, said sensor being capable of a change in color upon exposure to said analyte.    
     
     
         32 . The colorimetric sensor of  claim 31  wherein the change in color is from a visible color to a lack of visible color.  
     
     
         33 . The calorimetric sensor of  claim 31  wherein the change in color is due to delamination of the detection layer from an adjacent layer.