Fiber optic sensor, apparatus, and methods for detecting an organic analyte in a fluid or vapor sample

• US 5,244,813 A
• Filed: 04/20/1992
• Issued: 09/14/1993
• Est. Priority Date: 01/25/1991
• Status: Expired due to Term

• Current Assignee: Trustees of Tufts College
• Original Assignee: Trustees of Tufts College
• Inventors: Bernard, Steven M., Walt, David R.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/870,949
• Time in Patent Office: 512 Days
• Field of Search: 128/634, 385/12, 422/82.06, 422/82.07, 422/82.08, 422/82.09, 422/86, 422/88, 436/91, 436/126, 436/127, 436/128, 436/129, 436/130, 436/139, 436/140, 436/141, 436/142, 436/167, 436/172
• US Class Current: 436/172
• CPC Class Codes: G01N 2021/6434 Optrodes
• CPC Class Codes: G01N 2021/773 Porous polymer jacket; Polymer matrix with indicator
• CPC Class Codes: G01N 2021/7793 Sensor comprising plural indicators
• 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

Abstract

The present invention provides fiber optic sensors, apparatus, methods of optical detection, and methods of sensor manufacture for detection of organic analytes having a fixed polarity. The sensor requires an optical fiber strand; an immobilized polarity-sensitive dye; and an immobilized polymeric material which not only contains the polarity-sensitive dye but also absorbs and partitions the organic analyte of interest.

Claims

1. A fiber optic sensor for detecting an organic analyte of discernible polarity in a fluid sample, said fiber optic sensor comprising:

an optical fiber strand able to convey light energy of a predetermined wavelength, said optical fiber strand having a proximal end, a distal end, and a strand length;

at least one polarity-sensitive dye immobilized at the distal end of said optical fiber strand, said at least one polarity-sensitive dye being able to absorb light energy of a predetermined wavelength and change its spectral properties upon exposure to an entity of discernible polarity; and

at least one polymeric material immobilized at the distal end of said optical fiber strand in a manner such that said at least one immobilized polarity-sensitive dye is contained within and is surrounded by said at least one polymeric material and the spectral properties of said at least one contained polarity-sensitive dye are mediated by said surrounding at least one immobilized polymeric material, through which at least a portion of such organic analyte of discernible polarity as is presented by a fluid sample becomes absorbed and at least partially partitioned by said at least one immobilized polymeric material concomitant with making reactive contact with said at least one contained polarity-sensitive dye and a detectable change in the spectral properties of said at least one contained polarity-sensitive dye is produced as a consequence of such reactive contact.

3. The fiber optic sensor as recited in claim 1 or 2 wherein said optical fiber strand conveys exciting light energy of a first wavelength and emitted light energy of a second wavelength.

4. The fiber optic sensor as recited in claim 1 or 2 wherein said at least one polarity-sensitive dye is a chromophore.

5. The fiber optic sensor as recited in claim 1 or 2 wherein said at least one polarity-sensitive dye is a fluorophore.

6. The fiber optic sensor as recited in claim 1 or 2 wherein said at least one polymeric material is a silicone based polymer.

7. The fiber optic sensor as recited in claim 6 wherein said contained at least polarity-sensitive dye is Nile Red.

8. The fiber optic sensor as recited in claim 1 or 2 wherein said at least one polymeric material is selected from the group consisting of polyethylene, polypropylene, polymethylmethacrylate, polystyrene, polyhydroxyethylmethacrylate, polyurethanes, polyvinyl chlorides, polyvinylidene chloride, fluorinated polyolefins, parafilm, and chlorofluoro polyolefins.

2. A fiber optic sensor for detecting an organic analyte of discernible polarity in a fluid sample, said fiber optic sensor comprising:

an optical fiber strand able to convey light energy of a predetermined wavelength, said optical fiber strand having a proximal end, a distal end, and a strand length;

at least one polarity-sensitive dye immobilized at the distal end of said optical fiber strand, said at least one polarity-sensitive dye being able to absorb light energy of a predetermined wavelength and change its spectral properties upon exposure to an entity of discernible polarity;

at least one polymeric material immobilized at the distal end of said optical fiber strand in a manner such that said at least one immobilized polarity-sensitive dye is contained within and is surrounded by said at least one polymeric material and the spectral properties of said at least one contained polarity-sensitive dye are mediated by said surrounding at least one immobilized polymeric material, through which at least a portion of such organic analyte of discernible polarity as is presented by a fluid sample becomes absorbed and at least partially partitioned by said at least immobilized polymeric material concomitant with making reactive contact with said at least one contained polarity-sensitive dye and a detectable change in the spectral properties of said at least one contained polarity-sensitive dye is produced as a consequence of such reactive contact;

means for introducing light energy of a predetermined wavelength to the proximal end of said optical fiber strand; and

means for detecting light energy conveyed from said at least one contained polarity-sensitive dye.

9. The fiber optic sensor as recited in claim 2 wherein said means for detecting light energy allows for detection of emitted light energy of another wavelength.

10. A method for detecting an organic analyte of discernible polarity in a fluid sample, said method comprising the steps of:

admixing a fluid sample comprising an organic analyte of discernible polarity with a fiber optic sensor comprised of;

(a) an optical fiber strand able to convey light energy of a predetermined wavelength, said optical fiber strand having a proximal end, a distal end, and a strand length;

(b) at least one polarity-sensitive dye immobilized at the distal end of said fiber optic strand, said at least one polarity-sensitive dye being able to absorb light energy of a predetermined wavelength and change its spectral properties upon exposure to an entity of discernible polarity, and

(c) at least one polymeric material immobilized at the distal end of said optical fiber strand in a manner such that said at least one immobilized polarity-sensitive dye is contained within and is surrounded by said at least one polymeric material and the spectral properties of said at least one contained polarity-sensitive dye are mediated by said surrounding at least one immobilized polymeric material, through which at least a portion of such organic analyte of discernible polarity as is presented by the fluid sample becomes absorbed and at least partially partitioned by said at least one immobilized polymeric material concomitant with making reactive contact with said at least one contained polarity-sensitive dye and a detectable change in the spectral properties of said at least one contained polarity-sensitive dye is produced as a consequence of such reactive contact;

introducing light energy of a predetermined wavelength to the proximal end of said fiber optic sensor whereby said light energy is conveyed to said distal end of said optical fiber strand and said at least one contained polarity-sensitvie dye absorbs at lest a portion of said introduced light energy; and

detecting light energy conveyed from said at least one contained polarity-sensitive dye of said fiber optic sensor after reactive contact with the fluid sample, said detected light energy being a measure of the organic analyte of discernible polarity in the fluid sample.

11. A method for making a fiber optic sensor able to detect an organic analyte of discernible polarity in a fluid sample, said method comprising the steps of:

obtaining an optical fiber strand able to convey light energy of a predetermined wavelength, said optical fiber strand having a proximal end, a distal end, and a strand length;

admixing at least one polarity-sensitive dye to absorb light energy of a predetermined wavelength and change its spectral properties upon exposure to an entity of discernible polarity with at least one polymerizable material to form a reaction mixture; and

polymerizing said reaction mixture at the distal end of said optical fiber strand in a manner such that said at least one polarity-sensitive dye is contained within and is surrounded by an immobilized polymeric material and the spectral properties of said at least one contained polarity-sensitive dye are mediated by said surrounding immobilized polymeric material, through which at least a portion of such organic analyte of discernible polarity as is presented by a fluid sample becomes absorbed and at least partially partitioned by said immobilized polymeric material concomitant with making reactive contact with said at least one contained polarity-sensitive dye and a detectable change in the spectral properties of said at least one contained polarity-sensitive dye is produced as a consequence of such reactive contact.