Osmotic reaction detector for detecting biological and non-biological reactions

• US 7,790,111 B2
• Filed: 12/20/2004
• Issued: 09/07/2010
• Est. Priority Date: 12/20/2004
• Status: Expired due to Fees

• Current Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Daniels, Jonathan S., Lean, Meng H., Torres, Francisco E.
• Primary Examiner(s): JARRETT, LORE RAMILLANO
• Application Number:
  US11/017,394
• Publication Number:
  US 20060134601A1
• Time in Patent Office: 2,087 Days
• Field of Search: 422/82.02, 422/68.1, 73/644.7, 436/34
• US Class Current: 422/82.02
• CPC Class Codes: B01L 3/505 flexible containers not provided for above
• CPC Class Codes: G01N 13/04 Investigating osmotic effects
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures

Abstract

A method and apparatus for measuring the presence or absence of interaction between at least a first and second material of interest by measuring osmotic pressure changes in an osmotic cell. Changes in osmotic pressure are determined by measuring the amount of compression exhibited by a compressible, semi-permeable material positioned in the cell.

Claims

1. A system for detecting interactions between at least a first material of interest and a second material of interest, said system comprising:

one cavity for receiving and retaining at least said first and second materials of interest and said carrier fluid, said cavity having a bottom surface;

a compressible, semi-permeable polymer gel material comprising carbon black particles;

said compressible, semi-permeable material having an initial uncompressed state and a second compressed state indicating compression responsive to osmotic pressure acting on said compressible, semi-permeable material;

a mixture including at least first and second materials of interest and a carrier fluid is positioned above the semi-permeable material;

a top conductor and a bottom conductor, wherein the top conductor is positioned on a top surface of said compressible, semi-permeable material, and the bottom conductor is positioned at a bottom surface of said compressible, semi-permeable material, wherein said compressible, semi-permeable material has a conductance dependent on its compression state;

an interface surface positioned between said mixture and said top conductor;

a capacitance detector

configured to monitor compression changes in said compressible, semi-permeable material by measuring the capacitance across said pair of conductors; and

a pair of conductor lines connected to said top and bottom conductors and said capacitance detector, wherein said compressible, semi-permeable material, said mixture, said top and bottom conductors, said interface surface, said capacitance detector, and said pair of conductor lines are positioned inside said cavity.

2. A system according to claim 1, wherein said compressible, semi-permeable material is impermeable to at least one of said first and second materials of interest during the time scale needed for a measurement operation to be completed by the system and is permeable to said carrier fluid.

3. A system according to claim 1, wherein said compressible, semi-permeable material has a thickness of from 50-100 nm.

4. A system according to claim 1, wherein said compressible, semi-permeable material has an E modulus of from about 1 to 50 kPa.

5. A system according to claim 1, wherein pressure changes as low as 3.8 Pa can be detected in said material.

6. A system according to claim 1, wherein changes in concentration as low as 1.5 μ

M of at least one of said first and second materials of interest can be detected.

7. A system according to claim 1, wherein said compressible, semi-permeable material maintains a constant or near-constant volume under compression.

8. A system according to claim 1, wherein a volume of the mixture is less than 10 μ

L.

9. A system according to claim 1, wherein a volume of the mixture is less than or equal to 1 μ

L.

10. A system according to claim 1, wherein a volume of the mixture is less than or equal to 100 nL.

11. A system according to claim 1, wherein a volume of the mixture is less than or equal to 20 nL.

12. A system according to claim 1, wherein said system includes an array of said locations, and at least two of the locations of the array utilize different first and/or second materials of interest.