Method for forming nanoparticle films and application thereof

• US 7,212,284 B2
• Filed: 05/12/2004
• Issued: 05/01/2007
• Est. Priority Date: 05/12/2004
• Status: Expired due to Fees

• Current Assignee: Morpho Detection (Safran SA)
• Original Assignee: General Electric Company
• Inventors: Deng, Tao, Smentkowski, Amy Linsebigler
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US10/843,832
• Publication Number:
  US 20050255236A1
• Time in Patent Office: 1,084 Days
• Field of Search: 356/301
• US Class Current: 356/301
• CPC Class Codes: B05D 1/00 Processes for applying liquids or other fluent materials B05D5/00, B05D7/00 take precedence
• CPC Class Codes: B05D 1/20 substances to be applied floating on a fluid
• CPC Class Codes: B05D 1/202 Langmuir Blodgett films (LB films)
• CPC Class Codes: B05D 7/222 of pipes
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C03C 17/006 with materials of composite character
• CPC Class Codes: C03C 17/10 by deposition from the liquid phase
• CPC Class Codes: C03C 2217/255 Au
• CPC Class Codes: C03C 2217/42 consisting of particles only
• CPC Class Codes: C03C 2218/111 by dipping, immersion
• CPC Class Codes: C23C 2/04 characterised by the coating material
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: G01N 21/658 enhancement Raman, e.g. surface plasmons
• CPC Class Codes: Y10S 977/84 Manufacture, treatment, or detection of nanostructure
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles

Abstract

Disclosed herein is a method for making a nanoparticle film comprising dispersing nanoparticles in a first liquid; adding a second liquid to the first liquid to form a nanoparticle film on top of a solution comprising the first liquid, the second liquid and the nanoparticles, wherein the second liquid has a dielectric constant that is different from a dielectric constant of the first liquid; and contacting a substrate with the solution to deposit the nanoparticle film onto the contacted portion of the substrate. Disclosed herein too is a method for detecting an analyte comprising dispersing nanoparticles in a first liquid; adding a second liquid to the first liquid to form a nanoparticle film on top of a solution comprising the first liquid, the second liquid and the nanoparticles, wherein the second liquid has a dielectric constant that is different from a dielectric constant of the first liquid; contacting a substrate with the solution to deposit the nanoparticle film onto the substrate; disposing upon the nanoparticle film an analyte; and performing surface enhanced Raman spectroscopy to determine the identity of the analyte.

Claims

1. A method for making a nanoparticle film comprising:

dispersing nanoparticles in a first liquid, the first liquid capable of dissolving at least a portion of the nanoparticles;

adding a second liquid to the first liquid to form a nanoparticle film on top of a solution comprising the first liquid, the second liquid and the nanoparticles, wherein the second liquid has a dielectric constant that is different from a dielectric constant of the first liquid; and

contacting a substrate with the solution to deposit the nanoparticle film onto the contacted portion of the substrate.

2. The method of claim 1, further comprising adding a third and/or a fourth liquid to the solution, wherein the dielectric constant of the third and the fourth liquid are not equal to each other and are further different from the dielectric constant of the first liquid and the dielectric constant of the second liquid.

3. The method of claim 1, wherein the nanoparticles are solid and are made from a metal or wherein the nanoparticles are coated with a metal.

4. The method of claim 3, wherein the metal is copper, gold, platinum, palladium, aluminum, iron, titanium, vanadium, chromium, nickel, silver, tantalum, tungsten, tin, gallium, germanium, or combinations of at least two of the foregoing metals.

5. The method of claim 1, wherein the nanoparticles comprise a core that comprises a polymer, a ceramic or a metal, or a liquid, and wherein the core is coated with a metal.

6. The method of claim 1, wherein the nanoparticles have average particle sizes of less than or equal to about 500 nanometers.

7. The method of claim 1, wherein the nanoparticles are present in the solution in an amount of about 0.0000001 to about 20 wt %, based on the total weight of the solution.

8. The method of claim 1, wherein the first liquid and the second liquid have a dielectric constant of about 1 to about 1000.

9. The method of claim 1, wherein the nanoparticles are soluble in the first liquid.

10. The method of claim 1, wherein the first liquid and the second liquid are polar liquids, non-polar liquids, ionic liquids, or combinations comprising at least one of the foregoing liquids.

11. The method of claim 1, wherein the first liquid is present in an amount of about 1 to about 99.99 wt %, based on the total weight of the solution.

12. The method of claim 1, wherein the second liquid is present in an amount of about 1 to about 99.99 wt %, based on the total weight of the solution.

13. The method of claim 1, wherein the nanoparticles comprise gold, wherein the first liquid is water, the second liquid is ethanol and wherein the substrate comprises silica.

14. The method of claim 1, wherein the substrate comprises a polymer, a ceramic or a metal.

15. The method of claim 1, wherein the substrate has a surface that is flat, curved, grooved, braided, patterned, or a combination comprising at least one of the foregoing surfaces.

16. An article comprising the a nanoparticle film, said nanoparticle film comprising a plurality of nanoparticles, each of said plurality of nanoparticles including a core comprised of a ceramic material or a polymer, and a metal coating disposed on said core.

17. A method for detecting an analyte comprising:

dispersing nanoparticles in a first liquid, the first liquid capable of dissolving at least a portion of the nanoparticles;

adding a second liquid to the first liquid to form a nanoparticle film on top of a solution comprising the first liquid, the second liquid and the nanoparticles, wherein the second liquid has a dielectric constant that is different from a dielectric constant of the first liquid;

contacting a substrate with the solution to deposit the nanoparticle film onto the substrate;

disposing upon the nanoparticle film an analyte; and

performing surface enhanced Raman spectroscopy to determine the identity of the analyte.

18. The method of claim 17, wherein the analyte is present in a solution of the analyte in a concentration of less than or equal to about 1×

10<sup>−

6</sup> moles.

19. The method of claim 18, wherein the analyte is present in a concentration of less than or equal to about 1×

10 −

9 moles.

20. The method of claim 17, wherein the nanoparticles comprise gold, wherein the first liquid is water, the second liquid is ethanol and wherein the substrate comprises silica.