Methods and device for detecting and quantifying substances in body fluids

• US 6,040,194 A
• Filed: 06/06/1995
• Issued: 03/21/2000
• Est. Priority Date: 12/14/1989
• Status: Expired due to Fees

• Current Assignee: Sensory Technologies LLC (DSI Video Systems LLC)
• Original Assignee: Sensory Technologies LLC (DSI Video Systems LLC)
• Inventors: Chick, William L., Cardullo, Richard A., Wolf, David E.
• Primary Examiner(s): Housel, James C.
• Assistant Examiner(s): HINES, JANA A
• Application Number:
  US08/467,915
• Time in Patent Office: 1,750 Days
• Field of Search: 436/95, 436/501, 436/537, 436/805, 436/807, 436/815, 604/632, 604/633, 424/9.1, 424/9.6, 128/634, 435/4, 435/7.4, 435/7.7, 435/7.9, 435/7.92, 435/7.72, 435/6, 422/82.07, 422/82.08
• US Class Current: 436/501
• CPC Class Codes: A61K 49/0004 Screening or testing of compounds for diagnosis of disorders, assessment of conditions, e.g. renal clearance, gastric emptying, testing for diabetes, allergy, rheuma, pancreas functions
• CPC Class Codes: A61K 49/0006 Skin tests, e.g. intradermal testing, test strips, delayed hypersensitivity
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures
• CPC Class Codes: Y10S 436/815 Test for named compound or class of compounds
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

An in vivo method and apparatus for detecting an analyte in an individual. A sensor that includes a fluorescence reagent is placed in communication with the body fluids of the individual suspected of containing the analyte in such a way that once in place said sensor does not exit the skin of the individual. The sensor is configured to retain the fluorescence reagent while allowing analyte to diffuse into and out of said sensor. The sensor is illuminated transdermally, and the fluorescence from the fluorescence reagent associated with the presence of the analyte is measured.

Claims

1. An in vivo method for determining an analyte in the body fluids of an individual comprising the steps of

a) placing a sensor in communication with the body fluids of said individual suspected of containing said analyte in such a way that once in place said sensor does not exit the skin of the individual,

said sensor comprising a fluorescence reagent for detecting said analyte that reversibly binds to said analyte,

said fluorescence reagent having a fluorescence intensity, an emission spectrum, an excitation spectrum, or an excited state lifetime in the presence of said analyte that is different from its fluorescence intensity, emission spectrum, excitation spectrum, or excited state lifetime in the absence of said analyte,

said sensor being configured to retain said fluorescence reagent while allowing said analyte to diffuse into and out of said sensor;

b) transdermally illuminating said sensor; and

c) measuring the fluorescence intensity, emission spectrum, excitation spectrum, or excited state lifetime of said fluorescence reagent relative to the fluorescence intensity, emission spectrum, excitation spectrum, or excited state lifetime of said fluorescence reagent in the absence of said analyte; and

d) correlating the change in fluorescence intensity, emission spectrum, excitation spectrum, or excited state lifetime of said fluorescence reagent with the presence or amount of said analyte in said individual.

2. The method of claim 1 wherein said analyte is a carbohydrate.

3. The method of claim 2 wherein said carbohydrate is glucose or a derivative thereof.

4. The method of claim 1 wherein said fluorescence reagent comprises a fluorophore or compound labelled with said fluorophore that binds directly to said analyte.

5. The method of claim 4 wherein said fluorophore or compound labelled with said fluorophore exhibits a change in fluorescence intensity upon binding to said analyte, and said fluorescence is measured by measuring said change in fluorescence intensity.

6. The method of claim 4 wherein said fluorophore or compound labelled with said fluorophore exhibits a change in excitation or emission spectrum upon binding to said analyte, and said fluorescence is measured by measuring said change in the excitation or emission spectrum.

7. The method of claim 6 wherein the change in said excitation or emission spectrum of said fluorophore or compound labelled with said fluorophore is measured by measuring (a) the appearance or disappearance of emission peaks, (b) the ratio of the signal observed at two or more emission wavelengths, (c) the appearance or disappearance of excitation peaks, or (d) the ratio of the signal observed at two or more excitation wavelengths.

8. The method of claim 4 wherein said fluorophore or compound labelled with said fluorophore exhibits a change in excited state lifetime upon binding to said analyte, and said fluorescence is measured by measuring said change in the excited state lifetime.

9. The method of claim 1 wherein said fluorescence reagent comprises an analogue of said analyte labelled with a flourophore and a ligand capable of binding to both said analogue and said analyte.

10. The method of claim 9 wherein said analogue labelled with said fluorophore exhibits a change in fluorescence intensity upon binding to said analyte, and said fluorescence is measured by measuring said change in fluorescence intensity.

11. The method of claim 9 wherein said analogue labelled with said fluorophore exhibits a change in excitation or emission spectrum upon binding to said analyte, and said fluorescence is measured by measuring said change in the excitation or emission spectrum.

12. The method of claim 11 wherein the change in said excitation or emission spectrum of said analogue labelled with said fluorophore is measured by measuring (a) the appearance or disappearance of emission peaks, (b) the ratio of the signal observed at two or more emission wavelengths, (c) the appearance or disappearance of excitation peaks, or (d) the ratio of the signal observed at two or more excitation wavelengths.

13. The method of claim 9 wherein said analogue labelled with said fluorophore exhibits a change in excited state lifetime upon binding to said analyte, and said fluorescence is measured by measuring said change in the excited state lifetime.

14. The method of claim 1 wherein said fluorescence reagent comprises an analogue of said analyte and a ligand labelled with a fluorophore and capable of binding to both said analogue and said analyte.

15. The method of claim 14 wherein said ligand labelled with said fluorophore exhibits a change in fluorescence intensity upon binding to said analyte, and said fluorescence is measured by measuring said change in fluorescence intensity.

16. The method of claim 14 wherein said ligand labelled with said fluorophore exhibits a change in excitation or emission spectrum upon binding to said analyte, and said fluorescence is measured by measuring said change in the excitation or emission spectrum.

17. The method of claim 16 wherein the change in said excitation or emission spectrum of said ligand labelled with said fluorophore is measured by measuring (a) the appearance or disappearance of emission peaks, (b) the ratio of the signal observed at two or more emission wavelengths, (c) the appearance or disappearance of excitation peaks, or (d) the ratio of the signal observed at two or more excitation wavelengths.

18. The method of claim 14 wherein said ligand labelled with said fluorophore exhibits a change in excited state lifetime upon binding to said analyte, and said fluorescence is measured by measuring said change in the excited state lifetime.

19. The method of claim 1 wherein said fluorescence reagent is labelled with an energy-absorbing donor molecule and an energy-absorbing acceptor molecule, the excited state energy level of the donor overlapping with the excited state energy level of the acceptor, and said fluorescence is measured by determining the extent to which non-radiative fluorescence resonance energy transfer occurs between the donor and the acceptor upon binding.

20. The method of claim 19 wherein said fluorescence reagent comprises a specific binding pair, one member of which is labelled with said donor molecule and the other member of which is labelled with said acceptor molecule.

21. The method of claim 20 wherein said specific binding pair comprises a ligand capable of binding to said analyte and an analogue of said analyte capable of binding to said ligand.

22. The method of claim 19 wherein said fluorescence reagent comprises (a) a first ligand labelled with said energy-absorbing donor molecule and capable of binding to a first portion of said analyte and (b) a second ligand labelled with said energy-absorbing acceptor molecule and capable of binding to a second portion of said analyte different from said first portion, and said fluorescence is measured by determining the extent to which non-radiative fluorescence resonance energy transfer occurs between the donor and the acceptor upon binding.

23. The method of claim 19 wherein said fluorescence reagent comprises an agent capable of binding to said analyte, said agent being labelled with both said energy-absorbing donor molecule and said energy-absorbing acceptor molecule, said fluorescence being measured by determining the extent to which non-radiative fluorescence resonance energy transfer occurs between the donor and the acceptor upon binding.

24. The method of claim 19 wherein said illumination excites the donor and non-radiative fluorescence resonance energy transfer is determined by measuring the ratio of the fluorescence signal at two emission wavelengths, one of which is due to donor emission and the other of which is due to acceptor emission.

25. The method of claim 19 wherein said illumination is chosen such that it excites the donor at a first wavelength and the acceptor at a second wavelength, and non-radiative fluorescence resonance energy transfer is determined by measuring the ratio of the fluorescence signal due to the acceptor following donor excitation and the fluorescence signal due to the acceptor following acceptor excitation.

26. The method of claim 19 wherein said non-radiative fluorescence resonance energy transfer is determined by assessing whether there is a decrease in donor lifetime, a quenching of donor fluorescence, or an enhancement of acceptor fluorescence intensity.

27. The method of claim 19 wherein one or both of the donor-acceptor pair are fluorophores.

28. An in vivo method for determining an analyte in the body fluids of an individual comprising the steps of

a) placing a sensor in communication with the body fluids of said individual suspected of containing said analyte,

said sensor comprising a fluorescence reagent for detecting said analyte that reversibly binds to said analyte,

said sensor being configured to retain said fluorescence reagent while allowing analyte to diffuse into and out of said sensor,

said fluorescence reagent comprising an energy-absorbing donor molecule and an energy-absorbing acceptor molecule, the excited state energy level of the donor overlapping with the excited state energy level of the acceptor;

b) transdermally illuminating said sensor so as to

i) excite the donor or

ii) excite both the donor and acceptor; and

c) measuring the fluorescence from said fluorescence reagent associated with the presence of said analyte in said individual by determining the extent to which non-radiative fluorescence resonance energy transfer occurs between the donor and the acceptor upon binding,

said non-radiative fluorescence resonance energy transfer being determined by measuring

i) the ratio of the fluorescence signal at two emission wavelengths, one of which is due to donor emission and the other of which is due to acceptor emission, when only the donor is excited,

ii) the ratio of the fluorescence signal due to the acceptor following donor excitation and the fluorescence signal due to the acceptor following acceptor excitation,

iii) a change in donor lifetime,

iv) quenching of donor fluorescence, or

v) an enhancement of acceptor fluorescence intensity; and

d) correlating said non-radiative fluorescence resonance energy transfer with the presence or amount of said analyte in said individual.

29. An in vivo sensor for determining an analyte in the body fluids of an individual comprising a fluorescence reagent for determining said analyte that reversibly binds to said analyte,

said fluorescence reagent having a fluorescence intensity, an emission spectrum, an excitation spectrum, or an excited state lifetime in the presence of said analyte that is different from its fluorescence intensity, emission spectrum, excitation spectrum, or excited state lifetime in the absence of said analyte,

said sensor being configured such that (a) once implanted in the individual said sensor does not exit the skin of the individual, and (b) said fluorescence reagent is retained within said sensor while said analyte is allowed to diffuse into and out of said sensor.

30. An in vivo sensor for determining an analyte in the body fluids of an individual comprising a fluorescence reagent for determining said analyte that reversibly binds to said analyte,

said fluorescence reagent comprising an energy-accepting donor molecule and an energy-absorbing acceptor molecule, the excited state energy level of the donor overlapping with the excited state energy level of the acceptor,

said sensor being configured such that (a) once implanted in the individual said sensor does not exit the skin of the individual, and (b) said fluorescence reagent is retained within said sensor while said analyte is allowed to diffuse into and out of said sensor.