Fluorescent pH detector system and related methods

• US 7,968,346 B2
• Filed: 10/02/2009
• Issued: 06/28/2011
• Est. Priority Date: 08/19/2004
• Status: Expired due to Fees

• Current Assignee: Blood Cell Storage, Inc.
• Original Assignee: Blood Cell Storage, Inc.
• Inventors: Pfalzgraf, Randy D., Geelhood, Steven J., Harris, Paul C., Reed, Michael W.
• Primary Examiner(s): Siefke; Sam P
• Assistant Examiner(s): Kilpatrick; Bryan T
• Application Number:
  US12/572,566
• Publication Number:
  US 20100021958A1
• Time in Patent Office: 634 Days
• Field of Search: 436/163
• US Class Current: 436/163
• CPC Class Codes: G01N 2021/7786 Fluorescence
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• 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 21/80 Indicating pH value

Abstract

Fluorescent pH detector and methods for measuring pH using the fluorescent pH detector.

Claims

1. A method for measuring the pH of a sample, comprising:

(a) irradiating a fluorescent species immobilized on a substrate with excitation light emanating from a probe physically isolated from the sample and the fluorescent species immobilized on the substrate,

wherein the fluorescent species immobilized on the substrate is in liquid communication with the sample,

wherein the excitation light has a wavelength sufficient to effect fluorescent emission from the fluorescent species,

wherein the fluorescent species exhibits a first emission intensity at a first emission wavelength and a second emission intensity at a second emission wavelength, the ratio of the first and second emission intensities being dependent on pH; and

(b) measuring the first and second emission intensities to determined the pH of the sample.

2. The method of claim 1, wherein the probe is physically isolated from the fluorescent species immobilized on the substrate by a window transparent to the excitation light and the fluorescent emission.

3. The method of claim 1, wherein the probe comprises one or more optical fibers.

4. The method of claim 1, wherein the fluorescent species is selected from the group consisting of a naphthofluorescein compound and a seminaphthorhodamine compound.

5. The method of claim 1, wherein the naphthofluorescein compound is selected from the group consisting of a seminaphthofluorescein compound and a carboxynaphthofluorescein compound.

6. The method of claim 1, wherein the fluorescent species is a seminaphthofluorescein compound selected from the group consisting of 5′

(and 6′

)-carboxy-3,10-dihydroxy- spiro [7H-benzo [c]xanthene-7,1′

(3′

H)-isobenzofuran]-3′

-one and 2-(2-chloro-3-hydroxy-9-carboxyethyl-10-oxo-10H-benzo [c]xanthen-7-yl)benzoic acid.

7. The method of claim 1, wherein the fluorescent species immobilized on a substrate comprises a conjugate of a fluorescent species and a macromolecule.

8. The method of claim 7, wherein the macromolecule is an albumin.

9. The method of claim 1, wherein the fluorescent species immobilized on a substrate comprises a seminaphthofluorescein/human serum albumin conjugate.

10. The method of claim 1, wherein the sample comprises blood or a blood product.

11. The method of claim 1, wherein the sample is contained within a sealed vessel.