Methods and apparatus for improved luminescence assays using microparticles

Abstract

A method and apparatus for performing electrochemiluminescence assays are presented. In exemplary embodiments of the present invention an apparatus comprises an ECL-inactive electrode surface having a first assay-ligand immobilized thereon and an ECL-active microparticle having a second assay ligand immobilized thereon. In exemplary embodiments of the present invention a method comprises (a) forming a mixture comprising an electrochemiluminescent label and a microparticle having a first assay-ligand immobilized thereon, (b) applying electrochemical energy to an electrode surface in the presence of said mixture, and (c) measuring emitted electrochemiluminescence, where the microparticle is ECL-active and where the electrode surface is ECL-inactive when electrochemical energy is applied to it in the presence of said mixture.

1 . A microparticle comprised of an electrically conductive material having (a) one or more copies of an assay-ligand immobilized on its surface and (b) a plurality of electrochemiluminescent moieties immobilized on its surface. 
     
     
         2 . The microparticle of  claim 1  further comprised of a coating upon said electrically conductive material, wherein (a) said one or more copies of an assay-ligand are immobilized on said coating and (b) said plurality of electrochemiluminescent moieties are immobilized on said coating. 
     
     
         3 . A microparticle comprised of an electrically conductive material having a plurality of copies of an assay-ligand labeled with an electrochemiluminescent moiety immobilized on its surface. 
     
     
         4 . A microparticle comprised of an electrically conductive material having a plurality of copies of a binding reactant labeled with an electrochemiluminescent moiety immobilized on its surface. 
     
     
         5 . The microparticle of  claim 1 , wherein said binding reagent is an immunoreactant. 
     
     
         5 - 107 . (canceled)