Porous inorganic substrate for high-density arrays

• US 6,750,023 B2
• Filed: 03/18/2002
• Issued: 06/15/2004
• Est. Priority Date: 09/02/1999
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Tepesch, Patrick D., Wusirika, Raja R., Tanner, Cameron W.
• Primary Examiner(s): FORMAN, BETTY J
• Application Number:
  US10/101,135
• Publication Number:
  US 20030003474A1
• Time in Patent Office: 820 Days
• Field of Search: 435/6, 435/7.1, 435/174, 435/283.1, 435/287.2, 422/68.1
• US Class Current: 427/2.11
• CPC Class Codes: B01J 20/28033 Membrane, sheet, cloth, pad, lamellar or mat
• CPC Class Codes: B01J 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/28083 being in the range 2-50 nm, i.e. mesopores
• CPC Class Codes: B01J 20/28097 being coated, filled or plugged with specific compounds
• CPC Class Codes: B01J 2219/00529 DNA chips
• CPC Class Codes: B01J 2219/00533 essentially rectangular
• CPC Class Codes: B01J 2219/00576 fluorophore
• CPC Class Codes: B01J 2219/00608 DNA chips
• CPC Class Codes: B01J 2219/00612 the surface being inorganic
• CPC Class Codes: B01J 2219/0063 Other, e.g. van der Waals forces, hydrogen bonding
• CPC Class Codes: B01J 2219/00637 by coating it with another layer
• CPC Class Codes: B01J 2219/00641 the porous medium being continuous, e.g. porous oxide substrates
• CPC Class Codes: B01J 2219/00659 Two-dimensional arrays
• CPC Class Codes: B01J 2219/00677 Ex-situ synthesis followed by deposition on the substrate
• CPC Class Codes: B01J 2219/00722 Nucleotides
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C03C 11/005 obtained by leaching after a phase separation step
• CPC Class Codes: C03C 17/30 with silicon-containing compounds
• CPC Class Codes: C03C 2218/111 by dipping, immersion
• CPC Class Codes: C40B 40/06 Libraries containing nucleotides or polynucleotides, or derivatives thereof

Abstract

A porous inorganic substrate and method of fabricating such substrate for attaching an array of biological or chemical molecules to be used in a high-density microarray device. The substantially planar substrate comprises a porous inorganic layer adhered to a flat, rigid, non-porous, inorganic understructure having a coefficient of thermal expansion compatible with that of the porous inorganic layer. The porous inorganic layer is characterized as having dispersed throughout it a plurality of interconnecting voids as defined by a network of contiguous inorganic material, each of a predetermined mean size. The continuous inorganic material and contents of the voids exhibit a high contrast in their indices of refraction relative to each other. The substrate further comprises a uniform coating of a binding agent over at least a part of the surface area of the voids and the top surface of the porous inorganic layer.

Claims

1. A method of forming a substrate for attaching an array of biological or chemical analytes, said method comprises:

a) providing a flat, rigid, non-porous, impermeable, inorganic understructure;

b) applying a porous, predominantly inorganic layer to a top surface of said inorganic understructure;

wherein said porous inorganic layer is formed by an process that comprises;

1) applying a frit layer of individual particles of an inorganic material to a top surface of said inorganic understructure, said particles having a predetermined mean size of not less than 0.1 μ

m;

2) forming a network of inorganic material from said individual particles to create a plurality of interconnected voids of a predetermined mean size of not less than 0.1 μ

m dispersed through-out said porous inorganic layer, and having void channels that extend through to a top surface of said porous inorganic layer;

c) configuring said inorganic material and contents of said voids to exhibit a high contrast in their indices of refraction relative to each other such as to scatter light;

d) preparing said top surface of said porous inorganic layer for binding biological or chemical analytes.

2. The method according to claim 1, further comprising applying an interlayer disposed between said inorganic understructure and said porous inorganic layer, and said interlayer having a coefficient-of-thermal-expansion compatible with said inorganic understructure and with said porous inorganic layer.

3. The method according to claim 1, wherein said preparing step comprises applying a uniform coating of a binding agent over at least a part of a surface area of said voids and said top surface of said porous inorganic layer.

4. The method according to claim 3, wherein said binding agent is a cationic polymer.

5. The method according to claim 3, wherein said cationic polymer is either gamma-aminopropyltriethoxysilane or polylysine.

6. The method according to claim 1, wherein said inorganic material is characterized as a material that is non-absorbing and transparent to light when in the form of a solid of an amorphous or single crystal material.

7. The method according to claim 6, wherein said material is a glass, or a metal oxide.

8. The method according to claim 7, wherein said material is a silicate, aluminosilicate, boroaluminosilicate or borosilicate glass.

9. The method according to claim 7, wherein said material is TiO₂, SiO₂, Al₂O₃, Cr₂O₃, CuO, ZnO, or ZrO₂.

10. The method according to claim 1, wherein said porous inorganic layer has a thickness of at least 5 μ

m.

11. The method according to claim 1, wherein said inorganic material particles having a predetermined mean size in the range of about 0.3 μ

m to about 5 μ

m.

12. The method according to claim 1, further comprises after step b) and before step c) firing said porous inorganic layer at a temperature to adhere said individual particles into said network of inorganic material.

13. The method according to claim 1, wherein said voids have a predetermined mean size in the range of about 0.3 μ

m to about 5 μ

m.

14. The method according to claim 1, wherein said voids have a predetermined mean size in the range of about 0.5 μ

m to about 3.5 μ

m.

15. The method according to claim 1, wherein said content of said voids consists of either a gas, a liquid, or a solid.

16. The method according to claim 1, wherein said porous inorganic layer is characterized as having a microstructure that produces a sensitivity of fluorescent molecules of at least one order of magnitude greater than that of a comparable, non-porous substrate.

17. The method according to claim 1, wherein said substrate is fabricated using a tape casting process.

18. The method according to claim 1, wherein said substrate is fabricated using a screen printing process.

19. The method according to claim 1, wherein said porous inorganic layer has a coefficient of thermal expansion compatible with that of said inorganic understructure.

20. The method according to claim 1, wherein said inorganic material forms a continuous networked matrix.

21. The method according to claim 12, wherein said porous inorganic layer is fired at a temperature of about 650°

C. to about 735°

C.

22. The method according to claim 21, wherein said porous inorganic layer is fired at a temperature of about 650°

C. to about 720°

C.