Electrochemical affinity biosensor system and methods

• US 8,557,989 B2
• Filed: 09/25/2012
• Issued: 10/15/2013
• Est. Priority Date: 07/01/2003
• Status: Expired due to Fees

• Current Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Diebold, Eric R., Ghoshal, Mitali, Deng, David Z., Tsai, Jane Shiow-Chuan
• Primary Examiner(s): KOSACK, JOSEPH R
• Application Number:
  US13/626,358
• Publication Number:
  US 20130213822A1
• Time in Patent Office: 385 Days
• Field of Search: 546/10, 548/101, 205/775, 530/409
• US Class Current: 546/10
• CPC Class Codes: C07F 15/002 Osmium compounds
• CPC Class Codes: C07F 15/0026 without a metal-carbon linkage
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: G01N 2458/30 Electrochemically active labels
• CPC Class Codes: G01N 33/5306 Improving reaction conditions, e.g. reduction of non-specific binding, promotion of specific binding
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

The present invention provides novel osmium-based electrochemical species for the detection of wide variety of analytes using immunological techniques. The present invention also provides diagnostic kits and test sensors supporting electrode structures that can be used with the osmium-based electrochemical species. The test sensor can be fabricated to support interdigitated arrays of electrodes that have been designed to provide amplification of the electrical signal amplification desired to analyze analytes that may be present at low concentrations.

Claims

1. A compound of the formula:

2. The compound of claim 1 wherein R and R′

are the same and are selected from 2,2′

-bipyridyl, 4,4′

-disubstituted-2,2′

-bipyridyl, or 5,5′

-disubstituted-2,2′

-bipyridyl substituted with a methyl, an ethyl or a phenyl group.

3. The compound of claim 1 wherein L is —

(CH₂)_nNR³ and n is an integer between 1 and 10.

4. The compound of claim 1 wherein Q is NR³.

5. The compound of claim 1 wherein B comprises an epitope recognizable by an antibody capable of specific binding to an analyte.

6. The compound of claim 1 wherein B comprises an epitope capable of binding to an analyte selected from the group consisting of a biowarfare agent, an abused substance, a therapeutic agent, an environmental pollutant, a protein or a hormone.

7. The compound of claim 1 wherein X is selected from the group consisting of:

chloride, bromide, iodide, and fluoride.

8. A method of detecting an analyte in a liquid sample, said method comprising:

contacting a portion of said sample with a specific binding partner for said analyte and a redox reversible conjugate, said conjugate comprising the compound of claim 1;

simultaneously applying a first potential voltage to a first working electrode and a second potential voltage to a second working electrode using a bipotentiostat; and

measuring a current generated by a portion of the redox reversible conjugate not bound to the specific binding partner.

9. A compound of the formula:

10. The compound of claim 9 wherein A is —

(CH₂)_j—

NH₂ wherein j is an integer between 1-5.