Sensor for the determination of electrolyte concentrations

• US 4,892,640 A
• Filed: 07/12/1988
• Issued: 01/09/1990
• Est. Priority Date: 04/16/1985
• Status: Expired due to Fees

• Current Assignee: AVL AG
• Original Assignee: AVL AG
• Inventors: Braun geb. Hochmuth, Petra, Wolfbeis, Otto S.
• Primary Examiner(s): Tung, T.
• Application Number:
  US07/218,445
• Time in Patent Office: 546 Days
• Field of Search: 204/1 T, 204/403, 204/416-420, 250/458.1, 250/459.1, 324/96, 356/317, 356/318
• US Class Current: 204/403.06
• CPC Class Codes: G01N 27/3335 the membrane containing at least one organic component G01N27/3271 takes precedence; aspects concerning the enzyme reagent in enzyme electrodes C12Q1/001

Abstract

An ion-selective electrode for determining an electrolyte concentration in an aqueous solution includes an ion-selective layer and a potential-sensitive fluorescent indicator in the ion-selective layer, the fluorescence intensity of the potential-sensitive fluorescent indicator being measured to provide an indication of the electrolyte concentration.

Claims

1. A sensor for determining the concentration of an electrolyte in an aqueous sample solution, said sensor comprising an ion-selective membrane which contains valinomycin as an ion-carrier material and which has a first side that can be brought into contact with an electrolyte-containing aqueous sample solution, and a potential-sensitive fluorescent indicator immobilized at said first side of said ion-selective membrane, said fluorescent indicator, when excited, emitting fluorescence having an intensity which is dependent on a potential difference which arises at the boundary surface between said ion-selective membrane and said electrolyte-containing aqueous sample solution due to ion transport from said sample solution into said ion-selective membrane at said boundary surface by means of said ion-carrier material, said fluorescence intensity corresponding to the concentration of electrolyte in the electrolyte-containing aqueous sample solution.

2. A sensor according to claim 1, wherein said ionselective membrane includes a second side, and wherein said sensor includes a transparent carrier plate supporting said second side of said ion-selective membrane.

3. A sensor according to claim 2, wherein said transparent plate is composed of glass.

4. A sensor according to claim 1, wherein said ionselective membrane includes a second side which is opposite to said first side, and including a light conductor having an end in contact with said second side of said ion-selective membrane.

5. A sensor according to claim 4, wherein said light conductor is an optical fiber.

6. A sensor according to claim 4, wherein said potential-sensitive fluorescent indicator is rhodamine B.

7. A sensor according to claim 4, wherein said ion-selective membrane comprises a polymer membrane having a first side that can be brought into contact with an electrolyte-containing aqueous sample solution, and wherein said ion-carrier material is located at said first side of said polymer membrane.

8. A sensor for determining the concentration of an electrolyte in an aqueous sample solution, said sensor comprising an ion-selective membrane which contains N,N'"'"'-bibenzyl-N,N'"'"'-diphenyl-1, 2-phenylenedioxide-diacetamide as an ion-carrier material and which has a first side that can be brought into contact with an electrolyte-containing aqueous sample solution, and a potential-sensitive fluorescent indicator immobilized at said first side of said ion-selective membrane, said fluorescent indicator, when excited, emitting fluorescence having an intensity which is dependent on a potential difference which arises at the boundary surface between said ion-selective membrane and said electrolyte-containing aqueous sample solution due to ion transport from said sample solution into said ion-selective membrane at said boundary surface by means of said ion-carrier material, said fluorescence intensity corresponding to the concentration of electrolyte in the electrolyte-containing aqueous sample solution.

9. A sensor according to claim 8, wherein said ion-selective membrane includes a second side, and wherein said sensor includes a transparent carrier plate supporting said second side of said ion-selective membrane.

10. A sensor according to claim 9, wherein said transparent plate is composed of glass.

11. A sensor according to claim 8, wherein said ion-selective membrane includes a second side which is opposite to said first side, and including a light conductor having an end in contact with said second side of said ion-selective membrane.

12. A sensor according to claim 11, wherein said light conductor is an optical fiber.

13. A sensor according to claim 11, wherein said potential-sensitive fluorescent indicator is rhodamine B.

14. A sensor according to claim 11, wherein said ion-selective membrane comprises a polymer membrane having a first side that can be brought into contact with an electrolyte-containing aqueous sample solution, and an ion-carrier material at said first side of said polymer membrane.