Surface-enhanced raman medical probes and system for disease diagnosis and drug testing

• US 5,864,397 A
• Filed: 09/15/1997
• Issued: 01/26/1999
• Est. Priority Date: 09/15/1997
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Inventors: Vo-Dinh, Tuan
• Primary Examiner(s): Hantis, K. P.
• Application Number:
  US08/929,612
• Time in Patent Office: 498 Days
• Field of Search: 356/301, 356/300, 600/310, 600/314, 600/315, 600/316, 600/317, 600/318, 600/322, 600/323
• US Class Current: 356/301
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 21/658 enhancement Raman, e.g. surface plasmons

Abstract

A probe for a surface-enhanced Raman scattering spectrometer includes a member of optically transmissive material for receiving the excitation radiation from a laser and for carrying the radiation emitted from a specimen to a detector. An end of the member for placing against the specimen has a coating that produces surface enhancement of the specimen during Raman scattering spectroscopic analysis. Specifically the coating is formed by a first layer of microparticles on the member and a metal layer over the first layer. The first layer may form a microstructure surface over which a metal layer is applied. Alternatively the coating may be a material containing microparticles of a metal. An optional layer of a material may be applied to the metal layer to concentrate onto the probe compounds of analytical interest onto the probe.

Claims

1. A probe for a surface-enhanced Raman scattering spectrometer which has a source of excitation radiation and a detector for radiation emitted from a specimen being examined, the probe comprising:

a member of optically transmissive material for receiving the excitation radiation from the source and for carrying the radiation emitted from the specimen to the detector, the member having an end for placing against to the specimen;

a layer of optically transmissive material coated on the end of the member with the coating having a microstructured surface with protrusions; and

metal material applied to the layer of optically transmissive material for producing surface enhancement of the specimen during Raman scattering spectroscopic analysis.

2. The probe as recited in claim 1 wherein the member comprises an optical fiber.

3. The probe as recited in claim 1 wherein the end of the member is shaped to form a lens system.

4. The probe as recited in claim 1 wherein the end of the member is tapered.

5. The probe as recited in claim 1 wherein the metal material comprises metal particles between a one nanometer and one micrometer in size.

6. The probe as recited in claim 1 wherein the protrusions are between one nanometer and one micrometer high.

7. The probe as recited in claim 6 wherein the optically transmissive material is a polymer.

8. The probe as recited in claim 6 wherein the metal material comprises a layer of metal applied over the coating of optically transmissive material.

9. The probe as recited in claim 6 wherein the metal material comprises metal particles embedded the layer of optically transmissive material.

10. The probe as recited in claim 9 wherein the metal material is selected from the group consisting of alumina and titania.

11. The probe as recited in claim 1 wherein the metal material comprises a layer of a metal having a thickness of substantially no greater than 100 nm, thereby producing islands of metal at the end of the member of optically transmissive material.

12. The probe as recited in claim 11 wherein the layer of metal is selected from the group consisting of silver, gold, nickel, copper and cadmium.

13. The probe as recited in claim 1 further comprising a bioreceptor layer applied to the end of the member to concentrate onto the probe compounds to be analyzed spectroscopically.

14. The probe as recited in claim 1 further comprising a layer of a material applied to the end of the member to concentrates onto the probe compounds to be analyzed spectroscopically.

15. The probe as recited in claim 14 wherein the a layer of a material is selected from the group consisting of a polymer, an antibody, a protein, an enzyme, a nucleic acid and a molecular imprint material.

16. The probe as recited in claim 1 further comprising a sleeve of a material that is transparent to the excitation radiation wherein the sleeve removably extends around the end of the member, and the metal material is applied to the sleeve.

17. The probe as recited in claim 1 further comprising a removably coupling for attaching the member to an optical fiber.

18. The probe as recited in claim 1 wherein the member has an end surface that is beveled with a reflective material applied thereto, and the coating is applied to a side surface of the member through which the excitation radiation is reflected by the reflective material.