Glucose sensing molecules having selected fluorescent properties

• US 6,682,938 B1
• Filed: 09/15/2000
• Issued: 01/27/2004
• Est. Priority Date: 09/15/1999
• Status: Expired due to Term

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America), Minimed, Inc. (Medtronic Plc)
• Original Assignee: Minimed, Inc. (Medtronic Plc), Regents of the University of California (University of California)
• Inventors: Satcher, Joe H. Jr., Cary, Douglas R., Tran, Joe Anh, Darrow, Christopher B., Lane, Stephen M.
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Cole, Monique T.
• Application Number:
  US09/663,567
• Time in Patent Office: 1,229 Days
• Field of Search: 568/1, 436/172
• US Class Current: 436/172
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: C07F 5/025 Boronic and borinic acid compounds
• CPC Class Codes: C09B 19/00 Oxazine dyes
• CPC Class Codes: C09B 57/08 Naphthalimide dyes; Phthalimide dyes
• CPC Class Codes: C09B 57/10 Metal complexes of organic compounds not being dyes in uncomplexed form
• CPC Class Codes: G01N 33/52 Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose

Abstract

An analyte sensing fluorescent molecule that employs intramolecular electron transfer is designed to exhibit selected fluorescent properties in the presence of analytes such as saccharides. The selected fluorescent properties include excitation wavelength, emission wavelength, fluorescence lifetime, quantum yield, photostability, solubility, and temperature or pH sensitivity. The compound comprises an aryl or a substituted phenyl boronic acid that acts as a substrate recognition component, a fluorescence switch component, and a fluorophore. The fluorophore and switch component are selected such that the value of the free energy for electron transfer is less than about 3.0 kcal mol⁻¹. Fluorescent compounds are described that are excited at wavelengths greater than 400 nm and emit at wavelengths greater than 450 nm, which is advantageous for optical transmission through skin. The fluorophore is typically selected from transition metal-ligand complexes and thiazine, oxazine, oxazone, or oxazine-one as well as anthracene compounds. The fluorescent compound can be immobilized in a glucose permeable biocompatible polymer matrix that is implantable below the skin.

Claims

1. A method of making a fluorescent compound that emits a signal that can be correlated to an analyte concentration, wherein the compound has the general formula:

wherein R¹ is selected form the group consisting of hydrogen, lower aliphatic and aromatic functional groups;

wherein R² and R⁴ are optional functional selected from the group consisting of hydrogen, lower aliphatic and aromatic functional groups and groups that form covalent bonds to a polymer matrix;

wherein L¹ and L² are optional linking groups having from zero to four atoms selected from the group consisting of nitrogen, carbon, oxygen, sulfur, and phosphorus;

wherein Z is a heteroatom selected from the group consisting of nitrogen, sulfur, oxygen and phosphorus;

wherein R³ is an optional group selected from the group consisting of hydrogen, lower aliphatic and aromatic functional groups and groups that form covalent bonds to a polymer matrix;

wherein F is a fluorophore with selected molecular properties;

the method comprising selecting F and Z to satisfy the following equation such that Δ

G, the free energy for electron transfer, is less than about 3.0 kcal mol<sup>−

1</sup>;

3. The method as recited in claim 1, wherein F emits at a wavelength greater than about 500 nm.

4. The method as recited in claim 1, wherein F emits at a wavelength greater than about 550 nm.

5. The method as recited in claim 1, wherein F emits at a wavelength greater than about 600 nm.

6. The method as recited in claim 1, wherein the excitation wavelength for F is greater than about 400 nm.

7. The method as recited in claim 1, wherein the excitation wavelength for F is greater than about 450 nm.

8. The method as recited in claim 1, wherein F is selected from the group consisting of transition metal-ligand complexes, oxazines, oxazine-ones, oxazones, thiazines and anthracenes.

9. The method as recited in claim 8, wherein F comprises an oxazine-one boronate.

10. The method as recited in claim 1, wherein F comprises an anthracene-boronate.

11. The method as recited in claim 1, wherein F comprises a transition metal-ligand complex comprising a metal selected from the group consisting of ruthenium and chromium.

12. The method as recited in claim 1, wherein Z is nitrogen.

13. The method as recited in claim 1, wherein the fluorescent compound emits a signal that is correlated with the concentration of glucose.

2. A method of identifying a fluorescent compound having substituents with complimentary molecular properties, wherein the compound has the general formula:

wherein R¹ is selected from the group consisting of hydrogen, lower aliphatic and aromatic functional groups;

wherein R² and R⁴ are optional functional selected from the group consisting of hydrogen, lower aliphatic and aromatic functional groups and groups that form covalent bonds to a polymer matrix;

wherein L¹ and L² arc optional linking groups having from zero to four atoms selected from the group consisting of nitrogen, carbon, oxygen, sulfur, and phosphorus;

wherein Z is a heteroatom selected from the group consisting of nitrogen, sulfur, oxygen and phosphorus;

wherein R³ is an optional group selected from the group consisting of hydrogen, lower aliphatic and aromatic functional groups and groups that form covalent bonds to a polymer matrix;

wherein F is a fluorophore with selected molecular properties;

the method comprising determining whether F and Z satisfy the following equation such tat Δ

G, the free energy for electron transfer, is less than about 3.0 kcal mol<sup>−

1</sup>;

 

Δ

G=23.06[E⁰(Z^oxidation)−

E⁰(F^reduction)]−

Δ

E₀₀],

wherein E⁰(Z^oxidation) is the oxidation potential of Z, E⁰(F^reduction) is the reduction potential of F, and Δ

E₀₀ is the energy of F in the excited state.

14. The method as recited in claim 2, wherein F emits at a wavelength greater than about 500 nm.

15. The method as recited in claim 2, wherein F emits at a wavelength greater than about 550 nm.

16. The method as recited in claim 2, wherein F emits at a wavelength greater than about 600 nm.

17. The method as recited in claim 2, wherein the excitation wavelength for F is greater than about 400 nm.

18. The method as recited in claim 2, wherein the excitation wavelength for F is greater than about 450 nm.

19. The method as recited in claim 2, wherein F is selected from the group consisting of transition metal-ligand complexes, oxazines, oxazine-ones, oxazones, thiazines and anthracenes.

20. The method as recited in claim 19, wherein F comprises an oxazine-one boronate.

21. The method as recited in claim 19, wherein F comprises an anthracene-boronate.

22. The method as recited in claim 2, wherein F comprises a transition metal-ligand complex comprising a metal selected from the group consisting of ruthenium and chromium.

23. The method as recited in claim 2, wherein Z is nitrogen.

24. The method as recited in claim 2, wherein the fluorescent compound emits a signal that is correlated with the concentration of glucose.