Electrochemical sensor

• US 7,179,354 B2
• Filed: 05/07/2003
• Issued: 02/20/2007
• Est. Priority Date: 05/21/2002
• Status: Expired due to Fees

• Current Assignee: Tanita Corporation (Tanita)
• Original Assignee: Tanita Corporation (Tanita)
• Inventors: Harima, Shinichi, Uchiyama, Shunichi, Yajima, Tatsuhiko
• Primary Examiner(s): Noguerola; Alex
• Application Number:
  US10/430,301
• Publication Number:
  US 20030217919A1
• Time in Patent Office: 1,385 Days
• Field of Search: 204416-418, 204419-421, 204/433
• US Class Current: 204/422
• CPC Class Codes: G01N 27/301 Reference electrodes
• CPC Class Codes: G01N 27/302 pH sensitive, e.g. quinhydron, antimony or hydrogen electrodes ion selective electrodes G01N27/333, glass electrodes G01N27/36
• 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
• CPC Class Codes: G01N 27/401 Salt-bridge leaks; Liquid junctions
• CPC Class Codes: G01N 27/4035 Combination of a single ion-sensing electrode and a single reference electrode G01N27/406 and G01N27/413 take precedence
• CPC Class Codes: G01N 27/4167 pH electrodes therefor G01N27/302, G01N27/36
• CPC Class Codes: G01N 27/4168 Oxidation-reduction potential, e.g. for chlorination of water water analysis G01N33/18

Abstract

Disclosed is an electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode comprising a substrate that reacts to the liquid under test for generating an electric potential according to the concentration of the liquid under test, and said reference electrode comprising a substrate that reacts to the liquid under test for generating a fixed electric potential. According to the present invention, at least one of the work electrode and the reference electrode comprises said substrate coated with a function film for serving to generate the electric potential through the intervention of the film between said substrate and the liquid under test.

Claims

1. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising gold;

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said substrate and the liquid under test; and

wherein said reference electrode comprises a basic solution immersion film provided on said reference electrode substrate as said function film by immersing the reference electrode substrate in a basic solution comprising sodium hydroxide or potassium hydroxide.

2. An electrochemical sensor according to claim 1 wherein said work electrode comprises a plasma polymerized film having selective material transmission capability provided on said substrate, said plasma polymerized film consisting of at least one of an aromatic compound, a fluorinated compound, and an alcohol compound.

3. An electrochemical sensor according to claim 2 wherein said selective material transmission capability for said plasma polymerized film of the work electrode provides selective transmission of hydrogen ion.

4. An electrochemical sensor according to claim 2 wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

5. An electrochemical sensor according to claim 1 wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

6. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising silver coated with silver chloride film;

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said reference electrode substrate and the liquid under test;

wherein said reference electrode comprises a salt bridge retaining film provided on said reference electrode substrate as said function film;

wherein said work electrode comprises a plasma polymerized film having selective material transmission capability provided on said work electrode substrate, said plasma polymerized film consisting of at least one of an aromatic compound, a fluorinated compound, and an alcohol compound; and

wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

7. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising silver coated with silver chloride film;

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said reference electrode substrate and the liquid under test;

wherein said reference electrode comprises a salt bridge retaining film provided on said reference electrode substrate as said function film; and

wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

8. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising gold;

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said reference electrode substrate and the liquid under test;

wherein said reference electrode comprises a plasma polymerized film having selective material non-transmission capability provided on said gold reference electrode substrate as said function film, said plasma polymerized film consisting of at least one of an aromatic compound, a fluorinated compound, and alcohol compound;

wherein said work electrode comprises a plasma polymerized film having selective material transmission capability provided on said work electrode substrate, said plasma polymerized film consisting of at least one of an aromatic compound, a fluorinated compound, and an alcohol compound; and

wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

9. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising gold;

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said reference electrode substrate and the liquid under test;

wherein said reference electrode comprises a plasma polymerized film having selective material non-transmission capability provided on said gold reference electrode substrate as said function film, said plasma polymerized film consisting of at least one of an aromatic compound, a fluorinated compound, and alcohol compound; and

wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

10. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising silver coated with silver chloride film, or comprising gold,

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said reference electrode substrate and the liquid under test;

wherein said work electrode comprises a plasma polymerized film having selective material transmission capability provided on said work electrode substrate, said plasma polymerized film consisting of at least one of an aromatic compound, a fluorinated compound, and an alcohol compound; and

wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

11. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising silver coated with silver chloride film, or comprising gold,

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said reference electrode substrate and the liquid under test;

wherein said work electrode and said reference electrode are coated with a fixed hydrophobic film consisting of alkane polymer and annular olefin polymer.

12. An electrochemical sensor according to claim 11 wherein said work electrode and said reference electrode are integrally assembled, but insulated from each other.

13. An electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode having a substrate comprising at least one of platinum, gold, and platinum black, and said reference electrode having a substrate comprising silver coated with silver chloride film;

wherein said reference electrode substrate is coated with a function film for serving to generate the electric potential through the intervention of the film between said reference electrode substrate and the liquid under test;

wherein said reference electrode comprises a salt bridge retaining film provided on said reference electrode substrate as said function film; and

wherein said salt bridge retaining film is a perfluoroalkylsulfonic acid film impregnated with a salt bridge comprising potassium chloride or sodium chloride.

14. An electrochemical sensor according to claim 13 wherein said salt bridge is a mixture to which silver chloride is further added.