Electrochemical sensors with a chemically attached molecular redox buffer

Patent metadata

Field	Value
Publication number	US-2018024087-A1
Application number	US-201715655457-A
Country	US
Kind code	A1
Filing date	Jul 20, 2017
Priority date	Jul 21, 2016
Publication date	Jan 25, 2018
Grant date	—

Abstract

Solid-contact electrodes include a molecular redox buffer that is covalently attached to one of the components of the electrodes. These electrodes can be incorporated into electrochemical sensor systems. The electrode components are an electron conductor, a membrane and optionally, an interlayer. The electrode includes covalent attachment of the molecular redox buffer to the interlayer, to the electron conductor or the membrane. The interlayer includes nanoporous carbon such as CIM-carbon. The molecular redox buffer includes a well-defined redox pair, e.g., a complex of Co(II)/Co(III). The electrodes are ion-selective electrodes (ISEs) or reference electrodes. Methods include constructing solid contact electrodes and using the electrodes in electrochemical sensor systems to determine the quantity of an analyte in a sample. The electrochemical sensor systems include disposable paper-based devices and/or wearable devices for measuring analytes in a sample.

First claim

What is claimed is:

1 . A solid-contact (SC)-electrode comprising a molecular redox buffer covalently attached to one of the components of the electrode, wherein the components of the electrode comprise a solid electron conductor and a membrane.

2 . The SC-electrode of claim 1 , wherein the components further comprise an interlayer comprising nanoporous carbon, the interlayer located between the solid electron conductor and the membrane and wherein the molecular redox buffer is covalently attached to the interlayer, the electron conductor or the membrane.

3 . The SC-electrode of claim 2 , wherein the nanoporous carbon is colloid-imprinted mesoporous (CIM) carbon.

4 . The SC-electrode of claim 2 , wherein the molecular redox buffer comprises complexes with pyridines, bipyridines, terpyridines, porphyrins, phthalocyanines, phenanthrolines, acetylacetones, bipyridylimino isoindolines, crown ethers, cryptands and combinations thereof.

5 . The SC-electrode of claim 2 , wherein the molecular buffer comprises a redox couple selected from Co 2+ /Co 3+ , Os 2+ /Os 3+ , Fe 2+ /Fe 3+ , Cu + /Cu 2+ , Ni 2+ /Ni 3+ , Mn 2+ /Mn 3+ , Cr 2+ /Cr 3+ , Ru 2+ /Ru 3+ , Mo 4+ /Mo 5+ , Ag + /Ag 2+ , Ag 2+ /Ag 3+ , Sn 2+ /Sn 4+ , Pb 2+ /Pb 4+ and Ir 2+ /Ir 3+ .

6 . The SC-electrode of claim 2 , wherein the molecular redox buffer is attached to the interlayer, the membrane or the electron conductor through a reactive functional group.

7 . The SC-electrode of claim 6 , wherein the reactive functional group is selected from azide (−N 3 ), thiol (—SH), trichlorosilane, trialkoxysilane, amine, vinyl, styryl, allyl, haloalkyl, epoxide, isocyanate and silazane and wherein the linkages formed are ester linkages, amide linkages, carbon-carbon linkages or carbon-silicon linkages.

8 . The SC-electrode of claim 1 , wherein the solid electron conductor is selected from gold, platinum, silver, copper, steel, carbon, nickel, brass, indium-tin-oxide (ITO), fluorine-doped tin oxide (FTO), aluminum and combinations thereof.

9 . The SC-electrode of claim 2 , wherein the electrode is incorporated within an electrochemical sensor system comprising two or more electrodes.

10 . The SC-electrode of claim 9 , wherein the electrochemical sensor system measures analytes selected from H + , Li + , Na + , K + , Mg 2+ , Ca 2+ , Cu 2+ , Ag + , Zn 2+ , Cd 2+ , Hg 2+ , Pb 2+ , NH 4 + , carbonate, bicarbonate, nitrate, nitrite, sulfide, phosphate, chloride, iodide, perfluoroalkylsulfonates, perfluoroalkanoates and combinations thereof.

11 . The SC-electrode of claim 9 , wherein at least one of the electrodes in the electrochemical sensor system is a solid-contact reference electrode, and wherein the membrane in the reference electrode is a reference membrane.

12 . The SC-electrode of claim 9 , wherein at least one of the electrodes is a solid-contact ion-selective electrode, and wherein the membrane in the ion-selective electrode is an ion-selective membrane.

13 . The SC-electrode of claim 9 , wherein the system is a wearable system, an implantable system, a printed system, a paper based system or combinations thereof.

14 . A method of making an electrochemical sensor system, the method comprising:
forming a SC-electrode by covalently attaching a molecular redox buffer to one of the components of the electrode, the SC-electrode comprising an electron conductor and a membrane.

15 . The method of claim 14 , wherein the components further comprise an interlayer comprising nanoporous carbon, the interlayer located between the solid electron conductor and the membrane and wherein the molecular redox buffer is covalently attached to the interlayer, the electron conductor or the membrane.

16 . The method of claim 15 , wherein the nanoporous carbon interlayer is the CIM carbon interlayer.

17 . The method of claim 15 , wherein the molecular redox buffer comprises a redox couple selected from Co 2+ /Co 3+ , Os 2+ /Os 3+ , Fe 2+ /Fe 3+ , Cu + /Cu 2+ , Ni 2+ /Ni 3+ , Mn 2+ /Mn 3+ , Cr 2+ /Cr 3+ , Ru 2+ /Ru 3+ , Mo 4+ /Mo 5+ , Ag + /Ag 2+ , Ag 2+ /Ag 3+ , Sn 2+ /Sn 4+ , Pb 2+ /Pb 4+ and Ir 2+ /Ir 3+ .

18 . The method of claim 15 , wherein the molecular redox buffer is attached to the interlayer using a reactive functional group.

19 . The method of claim 18 , wherein the reactive functional group is selected from azide (—N 3 ), thiol (—SH), trichlorosilane, trialkoxysilanes, amine, vinyl, styryl, allyl, haloalkyl, epoxide, isocyanate and silazane and wherein linkages formed are ester linkages, amide linkages, carbon-carbon linkages or carbon-silicon linkages.

20 . The method of claim 15 , wherein the molecular redox buffer complex is synthesized prior to coupling to one of the components of the electrode.

21 . The method of claim 15 , wherein the molecular redox buffer is synthesized on the interlayer with a reactive functional group from reactant monomers.

22 . A method of measuring an analyte in a sample comprising:
contacting an ion-selective electrode in an electrochemical system with a sample, the electrochemical system comprising at least one SC-electrode, wherein the SC-electrode comprises a molecular redox buffer covalently attached to one of the components of the solid-contact electrode, the components comprising a solid electron conductor and a membrane.

23 . The method of claim 22 , wherein the components further comprise an interlayer comprising nanoporous carbon, the interlayer located between the solid electron conductor and the membrane and wherein the molecular redox buffer is covalently attached to the interlayer, the electron conductor or the membrane.

24 . The method of claim 23 , wherein the electrochemical sensor system comprises at least two SC-electrodes, and wherein at least one of the SC-electrodes comprises the ion-selective electrode or the reference electrodes.

25 . The method of claim 23 , wherein the sample is a clinical sample, an industrial sample, a forensic sample, an agricultural sample, a residential sample, a bodily fluid sample, or an environmental sample.

26 . The method of claim 23 , wherein the electrochemical system comprises a sensor, wherein the sensor is a potentiometric sensor, ion-sensitive field effect transistor, a voltammetric sensor, an amperometric sensor, a coulometric sensor, or an impedance sensor.

27 . The method of claim 23 , wherein the method further comprises correlating the results from the sensor to determine the quantity or concentration of the analyte.

28 . The method of claim 23 , wherein the analyte measured is selected from H + , Li + , Na + , K + , Mg 2+ , Ca 2+ , Cu 2+ , Ag + , Zn 2+ , Cd 2+ , Hg 2+ , Pb 2+ , NH 4 + , carbonate, bicarbonate, nitrate, nitrite, sulfide, phosphate, chloride, iodide, perfluoroalkylsulfonates, perfluoroalkanoates and combinations thereof.

Assignees

• Univ Minnesota

Inventors

• Hu Jinbo
• Buhlmann Philippe
• Stein Andreas
• Zhen Xue

Classifications

• G01N27/333 Primary

  Ion-selective electrodes or membranes (glass electrodes G01N27/36) · CPC title