Optical sensor-based cupric reducing antioxidant capacity (cuprac) assay

Abstract

An example embodiment is an apparatus for measuring antioxidant presence comprising a solid media, and a reagent carried by the media, the reagent reactive with at least one antioxidant to cause changes in light that is incident upon the reagent while carried by the solid media.

1 .- 15 . (canceled) 
     
     
         16 . A method for measuring antioxidant concentration in a material, the method comprising the steps of:
 exposing a reagent carried on a solid media to the material to cause a reduction of the reagent and a corresponding color change of the reagent;   illuminating the membrane with a light source to determine the color change;   using the color change to determine the concentration of antioxidant in the material.   
     
     
         17 . A method as defined by  claim 16  wherein the material is liquid phase, and wherein the step of exposing the reagent to the material comprises applying the liquid phase material to the solid media membrane. 
     
     
         18 . A method as defined by  claim 16  wherein:
 the media is a solid phase matrix; 
 the reagent is a CUPRAC reagent embedded in the membrane; and, 
 the reduction of the CUPRAC reagent results in a chelate formed on the surface of the membrane. 
 
     
     
         19 . A method as defined by  claim 16  wherein:
 the media is a perfluorosulfonate ion exchange membrane; 
 the reagent comprises a Cu(II)-Nc embedded in the membrane; and, 
 exposing the material to the reagent comprises reduction of the Cu(II)-Nc reagent to form a Cu(I)-Nc chelate. 
 
     
     
         20 . A method as defined by  claim 16  wherein using the color change to determine the antioxidant concentration comprises applying a linear color change scale to determine the total antioxidant capacity in the material over a range of antioxidant concentrations.