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 the presence of a target analyte comprising:
 a. providing an electrode comprising:
 i. a covalently attached a first capture binding ligand; 
 ii. a colloidal particle comprising a second capture binding ligand; and 
 iii. a target analyte, bound to said first and said second ligands; and 
   b. detecting an electronic signal from said electrode as an indication of the presence of said target analyte.   
     
     
         8 . A method according to  claim 7  wherein said first and said second capture binding ligands are nucleic acid sequences and said target analyte is a nucleic acid sequence. 
     
     
         9 . A method according to  claim 7  or  8  wherein said colloidal particle comprises a material selected from the group consisting of Au, Se, Te, Co, Ni, Fe, Cu and Pt. 
     
     
         10 . A method according to  claim 9  wherein said colloidal particle comprises Au. 
     
     
         11 . A method according to  claim 7  wherein said detecting utilizes AC voltametry. 
     
     
         12 . A method of detecting the presence of a target analyte comprising:
 a. providing an array of electrodes, each electrode comprising:
 i. a covalently attached first nucleic acid probe; 
 ii. a colloidal particle comprising a second nucleic acid probe; and 
 iii. a target nucleic acid, hybridized to said first and said second nucleic acid probes; 
   b. detecting a signal from said electrode as an indication of the presence of said target analyte.   
     
     
         13 . A method according to  claim 7  wherein said signal is electrical. 
     
     
         14 . A method according to  claim 7  wherein said signal is optical. 
     
     
         15 . A method according to  claim 12  wherein said colloidal particle comprises Au. 
     
     
         16 . A method of detecting a target analyte comprising forming an assay complex comprising contacting:
 a. a magnetic particle comprising a first capture binding ligand;   b. a colloidal particle comprising:
 i) a second capture binding ligand; and 
 ii) a third binding ligand different from said second binding ligand 
   c. a target analyte, bound to said first and said second binding ligands.   
     
     
         17 . A method according to  claim 8  wherein said colloidal particle comprises a material selected from the group consisting of Au, Se, Te, Co, Ni, Fe, Cu and Pt.