Detection of target analytes using particles and electrodes

Abstract

The invention relates to the use of particles comprising binding ligands and electron transfer moieties (ETMs). Upon binding of a target analyte, a particle and a reporter composition are associated and transported to an electrode surface. The ETMs are then detected, allowing the presence or absence of the target analyte to be determined.

1 - 6 . (canceled)  
     
     
         7 . A method of detecting cells using colloid particles, comprising: 
 a) forming an assay complex on a surface, wherein said assay complex comprises 
 1) said cells;  
 2) at least one colloid particle comprising a binding ligand; and  
 3) at least one signaling moiety that is either directly or indirectly attached to said assay complex; and  
   b) detecting said cells by detecting said signaling moiety.    
     
     
         8 . A method according to  claim 7 , wherein said surface is an electrode.  
     
     
         9 . A method according to  claim 7 , wherein said colloid particle is a gold colloid particle.  
     
     
         10 . A method according to  claim 7 , wherein said colloid particle further comprises a self-assembled monolayer (SAM).  
     
     
         11 . A method according to  claim 10 , wherein said SAM is a mixed SAM comprising a at least two species of molecules.  
     
     
         12 . A method according to  claim 10 , wherein said binding ligand is attached to said SAM via a transitional metal ligand.  
     
     
         13 . A method according to  claim 12 , wherein said transitional metal ligand comprises nickel.  
     
     
         14 . A method according to any of  claims 7  to  13 , wherein said binding ligand is a protein.  
     
     
         15 . A method according to  claim 7 , wherein said signaling moiety is an electron transfer moiety (ETM).  
     
     
         16 . A method according to  claim 7 , wherein said signaling moiety is a fluorescent moiety.  
     
     
         17 . A composition comprising a colloid particle comprising: 
 1) at least one signaling moiety; and    2) a mixed self-assembled monolayer (SAM), wherein said SAM comprises at least two species of molecules.    
     
     
         18 . A composition according to  claim 17 , wherein one of said species of molecules comprises a protein.  
     
     
         19 . A composition according to  claim 17 , wherein one of said species of molecule comprises an insulator.  
     
     
         20 . A composition according to  claim 19 , wherein said insulator comprises an alkyl or a heteroalkyl oligomer.  
     
     
         21 . A composition according to  claim 17 , wherein said signaling moiety comprises an electron transfer moiety (ETM).  
     
     
         22 . A composition comprising a colloid particle comprising: 
 a) a self-assembled monolayer (SAM); and    b) a non-DNA binding ligand attached to said colloid particle.    
     
     
         23 . A composition according to  claim 22 , wherein said binding ligand comprises a protein.  
     
     
         24 . A composition according to  claim 23 , wherein said protein is a peptide.