Sensor with overcoating and process for making same

• US 4,919,891 A
• Filed: 05/15/1987
• Issued: 04/24/1990
• Est. Priority Date: 04/18/1986
• Status: Expired due to Fees

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Hui, Henry K., Yafuso, Masao, Yan, Cheng F., Miller, William W.
• Primary Examiner(s): Richman, Barry S.
• Assistant Examiner(s): Johnston, Jill
• Application Number:
  US07/049,844
• Time in Patent Office: 1,075 Days
• Field of Search: 422/58, 422/68, 436/68, 436/167, 250/227, 356/39, 128/642, 427/2, 350/96.29, 350/96.3, 350/96.33
• US Class Current: 422/401
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: G01N 2021/6434 Optrodes
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/643 non-biological material
• CPC Class Codes: G01N 21/80 Indicating pH value
• CPC Class Codes: G01N 21/81 Indicating humidity
• CPC Class Codes: G01N 31/223 for investigating presence of specific gases or aerosols G01N31/221, G01N31/222 take precedence; actuation of fire alarm by presence of smoke or gases G08B17/10

Abstract

A sensor comprising a sensing element capable of sensing a component in an aqueous medium and an overcoating at least partially covering the sensing element. The overcoating comprises a water insoluble, component permeable, cross-linked cellulosic material and an effective amount of an opaque agent.

Claims

1. A sensor comprising a sensing element capable of sensing a component in an aqueous medium and an overcoating at least partially covering said sensing element, said overcoating comprising a water insoluble, component permeable cellulosic material cross-linked with one or more multi-functional cross-linking agents and an effective amount of an opaque agent.

2. The sensor of claim 1 wherein said sensing element is selected from the group consisting of optical indicators and electro-chemical indicators.

3. The sensor of claim 1 wherein, said sensing element is selected from the group consisting of optical indicators.

4. The sensor of claim 1 wherein said sensing element is selected from the group consisting of fluorescence indicators and absorbance indicators.

5. The sensor of claim 1 wherein said sensing element is selected from the group consisting of fluorescence indicators.

6. The sensor of claim 5 wherein said opaque agent is a dye adsorptive opaque agent.

7. The sensor of claim 6 wherein said opaque agent is a dye adsorptive opaque agent and said dye adsorptive opaque agent is carbon black.

8. The sensor of claim 6 wherein said sensing element is a fluorescence indicator capable of sensing carbon dioxide.

9. The sensor of claim 5, wherein said opaque agent is a dye non-adsorptive opaque agent.

10. The sensor of claim 9 wherein said dye non-adsorptive opaque agent is selected from the group consisting of ferric oxide and metallic phthalocyanines.

11. The sensor of claim 10 wherein said dye non-adsorptive opaque agent is a metallic phthalocyanine and the metallic portion of said phthalocyanine is selected from the group consisting of copper, iron, cobalt, lithium, magnesium, nickel, zinc, vanadium, manganese, sodium and mixtures thereof.

12. The sensor of claim 9 wherein said sensing element is a fluorescence indicator capable of sensing oxygen.

13. The sensor of claim 12 wherein said dye non-adsorptive opaque agent is copper phthalocyanine.

14. The sensor of claim 1 wherein said aqueous medium is a bodily fluid.

15. The sensor of claim 14 which further comprises a blood compatible film located on the outside surface of said overcoating.

16. The sensor of claim 1 wherein said aqueous medium is blood.

17. The sensor of claim 1 wherein said cross-linked cellulosic material is cross-linked cellulose.

18. The sensor of claim 1 wherein said component is selected from the group consisting of gases, hydrogen ions, other electrolytes and glucose.

19. The sensor of claim 1 wherein said component is selected from the group consisting of gases and hydrogen ions.

20. The sensor of claim 1 wherein said component is selected from the group consisting of oxygen, carbon dioxide and hydrogen ions.

21. An overcoated sensing element produced in accordance with the process comprising:

contacting a sensing element with a composition containing a solvent and a solvent soluble cellulosic coating material or a solvent soluble precursor of said cellulosic coating material to form a composition coated sensing element; and

treating said composition coated sensing element to form an overcoating on said sensing element, said overcoating being permeable to a component of interest, wherein said composition further includes a permeability enhancing agent in an amount effective to enhance the component permeability of said overcoating formed.

22. An overcoated sensing element as defined in claim 21 wherein said permeability enhancing agent is substantially removed from said composition coated sensing element during said treating step.

23. An overcoated sensing element as defined in claim 22 wherein said permeability enhancing agent is water soluble and said treating step comprises contacting said composition coated sensing element at conditions effective to form a cross-linked cellulosic material on said sensing element and contacting said sensing element containing said cross-linked cellulosic material with an aqueous liquid at conditions effective to substantially remove said permeability enhancing agent.

24. An overcoated sensing element as defined in claim 23 wherein said composition coated sensing element is contacted at conditions effective to hydrolyze at least a portion of said cellulosic material on said sensing element, and said sensing element containing said hydrolyzed cellulosic material is contacted with at least one cross-linking agent at conditions effective to form a cross-linked cellulosic material on said sensing element.

25. A probe capable of sensing a plurality of different components in an aqueous medium which comprises:

a plurality of sensing elements each of which is capable of sensing a different one of said components in said aqueous medium;

a plurality of first overcoatings each of which is located on a different one of said sensing elements and each of which comprises a water insoluble, component permeable cellulosic material cross-linked with one or more multi-functional cross-linking agents and an effective amount of first opaque agent; and

a second overcoating located on all said first overcoated sensing elements and comprising a water insoluble, all component permeable cellulosic material cross-linked with one or more multi-functional across-linking agents.

26. The probe of claim 25 wherein said sensing elements are selected from the group consisting of optical indicators and electro-chemical indicators.

27. The probe of claim 26 wherein said aqueous medium is a bodily fluid.

28. The probe of claim 25 wherein said sensing elements are selected from the group consisting of optical indicators.

29. The probe of claim 25 wherein said sensing elements are selected from the group consisting of fluorescence indicators and absorbance indicators.

30. The probe of claim 25 wherein said sensing elements are selected from the group consisting of fluorescence indicators.

31. The probe of claim 30 wherein each of said first opaque agents is a dye adsorptive opaque agent.

32. The probe of claim 31 wherein said second overcoating further comprises an effective amount of a second opaque agent and wherein said second opaque agent is a dye non-adsorptive opaque agent.

33. The probe of claim 32 wherein said dye adsorptive opaque agent is carbon black and said dye non-adsorptive opaque agent is copper phthalocyanine.

34. The probe of claim 30 wherein each of said first opaque agents is a dye non-adsorptive opaque agent.

35. The probe of claim 25 wherein said second overcoating further comprises an effective amount of a second opaque agent.

36. The probe of claim 25 wherein said aqueous medium is blood.

37. The probe of claim 25 wherein said cross-linked cellulosic material is cross-linked cellulose.

38. The probe of claim 25 wherein said components are selected from the group consisting of gases, hydrogen ions, other electrolytes and glucose.

39. The probe of claim 25 wherein said aqueous medium is blood and said probe further comprises a blood compatible film located on said second overcoating.