Raman optrode processes and devices for detection of chemicals and microorganisms

• US 5,866,430 A
• Filed: 05/27/1997
• Issued: 02/02/1999
• Est. Priority Date: 06/13/1996
• Status: Expired due to Fees

• Current Assignee: Ann E. Grow
• Original Assignee: Ann E. Grow
• Inventors: Grow, Ann E.
• Primary Examiner(s): WEBER, JON P
• Application Number:
  US08/864,015
• Time in Patent Office: 616 Days
• Field of Search: 436/172, 436/20
• US Class Current: 506/6
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 2021/653 Coherent methods [CARS]
• CPC Class Codes: G01N 2021/655 Stimulated Raman
• CPC Class Codes: G01N 2021/656 Raman microprobe
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 21/658 enhancement Raman, e.g. surface plasmons
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 35/00009 provided with a sample supporting tape, e.g. with absorbent zones

Abstract

A methodology and devices for detecting or monitoring or identifying chemical or microbial analytes are described. The methodology comprises four basic steps: (1) The gas or liquid medium to be monitored or analyzed is brought into contact with a bioconcentrator which is used to bind with or collect and concentrate one or more analytes. (2) The bioconcentrator-analyte complex is then exposed to radiation of one or more predetermined wavelengths to produce Raman scattering spectral bands. (3) At least a portion of the Raman spectral bands are collected and processed by a Raman spectrometer to convert the same into an electrical signal. And (4) the electrical signal is processed to detect and identify, qualitatively and/or quantitatively, the analyte(s). The methodology of this invention may also comprise Raman reactive capacity analysis of the bioconcentrator itself, simultaneously with or independently from the detection of the analyte, to determine the potential ability of the bioconcentrator to complex with analytes; the results of this latter analysis may be used to affect or alter or modify the methodology involved in detection and analysis of the analytes. Also the invention is accomplished by a Raman Optrode comprising: a bioconcentrator capable of binding with the analyte(s); a mechanism or procedure or device for bringing the gas or liquid sample into contact with the bioconcentrator; a light source suitable for generating Raman scattering; a Raman spectrometer capable of collecting and processing the Raman scattering spectral information and translating it into an electrical signal; and electronic hardware and software for analyzing the electrical signal and translating the signal into information on the presence, identity and/or quantity of the bound analytes. Various forms of bioconcentrators are described, as well as a variety of analytes which may be detected, monitored, or identified by this invention, and a variety of devices which can be fabricated based on this invention.

Claims

1. The process for any one of at least the detection, identification and quantification of one or more analytes by Raman spectroscopy comprising the steps of:

providing a bioconcentrator which binds with at least one analyte,

bringing into contact with said bioconcentrator at least one analyte to effect binding of the at least one analyte on to the bioconcentrator to form a medium to be analyzed consisting essentially of said bioconcentrator and said at least one analyte and wherein at least some of said at least one analyte is bound to said bioconcentrator,

irradiating the said medium containing said bioconcentrator and the bound at least one analyte thereon with light from a source wherein said light produces Raman scattering from the irradiated bioconcentrator and the at least one analyte bound thereto, wherein the Raman scattering is not produced by a reporter attached to either the bioconcentrator or the analyte,

collecting and processing the Raman scattering emanating from said bioconcentrator and the at least one analyte on said bioconcentrator, and

analyzing the processed Raman scattering to determine the presence and/or identity of the at least one analyte.

2. The process as set forth in claim 1 wherein the bioconcentrator is located on a support member and wherein the bioconcentrator is selected from the group consisting of:

molecules, macromolecules, complexes, fragments of a molecule, and fragments and subunits of a complex, all derived from a biological source;

ligands that will bind molecules, macromolecules, complexes, fragments of a molecule, subunits of a complex, and fragments of a complex, all derived from a biological source;

wherein said molecules, macromolecules and complexes are selected from the group consisting of enzymes, enzyme cofactors, coenzymes, antibodies, antibody fragments, hemeproteins, natural and synthetic peptides, glycosphingolipids, lectins, lipids, phospholipids, carbohydrates, saccharides, gangliosides, nucleic acids, fragments of nucleic acids, pathogen adhesion factors, receptors, receptor subunits, liposomes, membranes, organelles, cells, tissues, complexes containing said molecules or macromolecules, and wherein said ligands are selected from the group consisting of enzyme substrates, enzyme inhibitors, antigens, antigen analogues, haptens, receptor agonists, receptor antagonists and sugars.

3. The process as set forth in claim 1 wherein said light is from a laser.

4. The process as set forth in claim 1 wherein said collecting and processing step includes the use of a Raman spectrometer in said processing.

5. The process as set forth in claim 4 wherein said spectrometer is an imaging spectrometer.

6. The process as set forth in claim 1 wherein the step of analyzing the processed Raman scattering includes the step of comparing the Raman spectrum of said medium containing said bioconcentrator and said bound analyte against the Raman spectrum of a reference standard having a known Raman spectrum corresponding to that of the same bioconcentrator and bound analyte.

7. The process as set forth in claim 1 wherein the analyte is in solution.

8. The process as set forth in claim 1 wherein the analyte is airborne.

9. The process as set forth in claim 1 wherein said at least one analyte comprises multiple analytes.

10. The process as set forth in claim 9 wherein said multiple analytes are bound on one bioconcentrator.

11. The process as set forth in claim 10 herein said multiple analytes are bound at different locations on said bioconcentrator.

12. The process as set forth in claim 1 wherein said steps are conducted at the same physical location.

13. The process as set forth in claim 1 wherein said step of bringing into contact with said bioconcentrator is conducted at one location and said steps of irradiating, collecting and analyzing are conducted at a different location from said step of bringing into contact with said bioconcentrator.

14. The process as set forth in claim 1 wherein said step of irradiating is performed continuously for real time analysis of the at least one analyte.

15. The process as set forth in claim 1 wherein said collecting and processing step is carried out by a Raman spectrometer selected from the group consisting of:

dispersing spectrometers, multichannel spectrometers, Fourier transform spectrometers, Hadamard transform spectrometers, stationary transform spectrometers, acousto-optic tunable filter spectrometers, integrated optic acousto-optic tunable filter spectrometers, fiber optic spectrometers, fiber optic array spectrometers, microscope spectrometers, imaging spectrometers, and imaging microscope spectrometers.

16. The process as set forth in claim 1 wherein said Raman scattering is selected from the group consisting of:

normal Raman scattering, surface enhanced Raman scattering, resonance Raman scattering, surface enhanced resonance Raman scattering and Raman evanescent wave scattering.

17. The process as set forth in claim 2 wherein said support member includes a roughened metal surface.

18. The process as set forth in claim 1 wherein said bioconcentrator is maintained stationary.

19. The process as set forth in claim 1 wherein said bioconcentrator is moved.

20. The process as set forth in claim 1 wherein a portion of the bioconcentrator is protected against contact with the analyte, and the analysis step includes the step of comparing one or more of the wavebands associated with the protected portion of the bioconcentrator with the Raman spectral signal of one or more wavebands emanating from the unprotected portion of the bioconcentrator and the bound at least one analyte.

21. The process as set forth in claim 2 wherein a chemical having a known Raman spectrum is located on said support member, and wherein said step of analyzing the processed Raman scattering includes the step of comparing the Raman spectrum of the bioconcentrator and the at least one analyte bound thereto against the Raman spectrum of said chemical.

22. The process as set forth in claim 1 wherein said analyzing is accomplished by comparing at least one waveband in the Raman spectrum of said medium containing said bioconcentrator and the at least one analyte bound thereto, said waveband being known to remain unchanged when the binding of the at least one analyte to the bioconcentrator is effected from the same waveband in the Raman spectrum of the unbound bioconcentrator, to at least one other waveband in said Raman spectrum of said medium containing said bioconcentrator and the at least one analyte bound thereto, said at least one waveband being known to change when the binding of the at least one analyte to the bioconcentrator is effected from the same at least one other waveband in the spectrum of the unbound bioconcentrator.

23. The process as set forth in claim 1 wherein there are several bioconcentrators located on one support member, and

an analyte is bound to each bioconcentrator and wherein the Raman spectrum from each bioconcentrator is analyzed.

24. The process as set forth in claim 1 wherein said analyzing comprises:

determining the spectrum of the bioconcentrator,

setting the values of the bioconcentrator to zero and comparing the value of the Raman scattering spectrum from the analyte bound to the bioconcentrator to said zero value.