Assay devices that utilize hollow particles

• US 7,829,328 B2
• Filed: 05/25/2006
• Issued: 11/09/2010
• Est. Priority Date: 04/03/2003
• Status: Expired due to Fees

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Atanassov, Zdravko Savov, Wei, Ning, Yang, Kaiyuan, Chidebelu-Eze, Chibueze Obinna, Kaylor, Rosann
• Primary Examiner(s): Yang; Nelson
• Application Number:
  US11/440,956
• Publication Number:
  US 20060216834A1
• Time in Patent Office: 1,629 Days
• Field of Search: 436/533, 436/534, 436/514, 435/7.34, 435/36
• US Class Current: 435/288.7
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G01N 33/587 Nanoparticles

Abstract

Hollow particles for use in various types of assay devices are provided. Due to their hollow or voided structure, the particles may exhibit a variety of beneficial properties. For instance, hollow particles are generally lightweight, and thus, relatively inexpensive in comparison to other types of particles. Hollow particles may also form a stable system without requiring refrigeration or rotation. In addition, hollow particles may possess enhanced light diffraction capabilities, which may be particularly beneficial in certain types of assay devices, e.g., diffraction-based assay devices.

Claims

1. An assay device for detecting an analyte in a test sample, the assay device comprising:

a porous membrane that defines a detection zone, wherein a biological receptive material is immobilized within the detection zone; and

detection probes that contain latex particles having an average size of from about 0.1 nanometer to about 100 microns, wherein the latex particles individually define a polymeric shell about a hollow interior constituting at least about 20% of the spatial volume occupied by the particle, wherein the polymeric shell of the latex particles comprises an organic polymer covalently conjugated with a specific binding member for the analyte, wherein the organic polymer is covalently conjugated with the specific binding member via a carboxylic functional group on the organic polymer, and wherein any remaining activated carboxylic functional groups on the organic polymer of the polymeric shell are blocked;

wherein the detection probes are capable of generating a detection signal when present within the detection zone.

2. The assay device of claim 1 wherein the hollow interior constitutes at least about 30% of the spatial volume occupied by the particle.

3. The assay device of claim 1, wherein the average size of the latex particles ranges from about 1 nanometer to about 10 microns.

4. The assay device of claim 1, wherein the organic polymer has a glass transition temperature that is greater than about 50°

C.

5. The assay device of claim 1, wherein the organic polymer is formed one or more ethylenically unsaturated monomers.

6. The assay device of claim 1, wherein the latex particles have a spherical shape.

7. The assay device of claim 1, wherein the latex particles are monodispersed.

8. The assay device of claim 1, wherein the organic polymer is covalently conjugated with the specific binding member via an amide bond.

9. The assay device of claim 8, wherein the organic polymer is covalently conjugated with the specific binding member via the carboxylic functional group on the organic polymer after activation of the carboxylic functional group using carbodiimide and subsequent reaction with an amino group of an antibody to form the amide bond.

10. The assay device of claim 9, wherein any remaining activated carboxylic functional groups on the organic polymer of the polymeric shell are blocked with ethanolamine.

11. The assay device of claim 1, wherein the covalent conjugation with the specific binding member is accomplished using carboxylic, amino, aldehyde, bromoacetyl, idodacetyle, thiol, or epoxy functional groups.

12. The assay device of claim 1, wherein the specific binding member comprises an immunoreactive specific binding member.

13. The assay device of claim 12, wherein the immunoreactive specific binding member comprises an antigen, hapten, aptamer, antibody, or complexes thereof.

14. The assay device of claim 12, wherein the immunoreactive specific binding member comprises an antigen.