Patent ID: 7989220
Filing Date: 2011-08-02
Classification: G01N

Abstract:
1. A method for determining the quantity of an analyte comprising: a) providing a functionalized substrate that comprises metallic nanoparticles and a plurality of substantively identical bioactive target molecules affixed to a substrate, wherein the bioactive target molecule binds to a particular analyte; b) providing a reagent comprising a plurality of substantively identical detection molecules, wherein the detection molecule comprises a fluorophore, and the detection molecule binds to the particular analyte or competes with the particular analyte for binding to the target molecule; c) contacting the functionalized substrate to a test sample and the reagent; d) exposing the functionalized substrate and a covering solution resulting from step c) to polarized electromagnetic waves that excite the fluorophore; and e) determining a quantity of the particular analyte in the test sample based on measuring polarization anisotropy of fluorescent emissions directly from the substrate and the covering solution, wherein the detection molecule is selected so that polarization anisotropy decreases with an increase in a ratio of a number of detection molecules bound directly or indirectly to the functionalized substrate divided by a number of free detection molecules in the covering solution.