ELECTROCHEMICAL DETECTION OF NITRO-CONTAINING COMPOUNDS

• US 20180372673A1
• Filed: 06/14/2018
• Published: 12/27/2018
• Est. Priority Date: 06/15/2017
• Status: Active Grant

• Current Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Original Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Inventors: Patolsky, Fernando, Krivitsky, Vadim, Filanovsky, Boris
• Granted Patent: US 10,948,451 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 27/304 Gas permeable electrodes
• CPC Class Codes: G01N 27/308 at least partially made of carbon
• CPC Class Codes: G01N 27/4045 for gases other than oxygen
• CPC Class Codes: G01N 33/0057 Warfare agents or explosives

Abstract

A carbon electrode having a functional moiety that forms a charge-transfer complex with a nitro-containing compound covalently attached to a surface of the electrode, and a process of preparing such an electrode are provided. Also provided are sensing systems integrating the carbon electrode and methods utilizing same for electrochemical detection of nitro-containing compounds.

Claims

1. A sensing electrode comprising a carbon electrode and a functional moiety covalently attached to a surface of said electrode, said functional moiety being such that forms a charge-transfer complex with a nitro-containing compound.

2. The electrode of claim 1, wherein said carbon electrode is a carbon fiber microelectrode.

3. The electrode of claim 1, wherein said carbon electrode is a carbon paper microelectrode.

4. The electrode of claim 1, wherein said carbon electrode is gas-permeable.

5. The electrode of claim 1, wherein said carbon electrode is a surface-modified carbon electrode featuring a plurality of surface reactive groups.

6. The electrode of claim 1, wherein said functional moiety comprises an electron donating moiety.

7. The electrode of claim 6, wherein said electron donating moiety is a C_1-10 alkyl substituted by an electron donating group.

8. The electrode of claim 7, wherein said electron donating group is amine.

9. The electrode of claim 1, wherein said functional moiety comprises a silyl substituted by an aminoalkyl, said alkyl being 1-10 carbon atoms in length.

10. The electrode of claim 1, usable for determining a presence and/or level of a nitro-containing compound in a sample, upon integrating the electrode in an electrochemical cell which further comprises an electrolyte.

11. A sensing system comprising a sensing electrode according to claim 1, the sensing electrode being connectable to a power source.

12. The sensing system of claim 11, wherein said sensing electrode forms a part of an electrochemical cell.

13. The system of claim 12, further comprising an electrolyte solution in contact with said sensing electrode.

14. The system of claim 13, wherein said electrolyte features a pH lower than 8, or lower than 7.

15. The system of claim 13, wherein said electrolyte comprises a mixture of an aqueous solvent and an organic solvent.

16. The system of claim 13, wherein said electrolyte comprises a quaternary ammonium salt.

17. The system of claim 11, being devoid of means for deaerating the system prior to contacting the system with a sample.

18. The system of claim 11, further comprising a power source electrically connected to said sensing electrode.

19. The system of claim 11, further comprising a device for measuring an electrochemical parameter of said sensing electrode.

20. The system of claim 11, wherein said electrochemical cell is configured such that upon contacting a sample containing a nitro-containing compound with said sensing electrode, a presence and/or level of an electrochemical parameter generated in response to applying potential to said sensing electrode is indicative of a presence and/or level of the nitro-containing compound.

21. A method of detecting a nitro-containing compound in a sample, the method comprising:

contacting the sample with a sensing electrode according to claim 1;

applying potential to said sensing electrode; and

measuring an electrochemical parameter of said sensing electrode, wherein a presence and/or level of said parameter is indicative of a presence and/or level of the nitro-containing compound in the sample.

22. The method of claim 21, wherein said electrochemical parameter comprises an electrical current generated at said sensing electrode, wherein a presence and/or level of said electrical current is indicative of a presence and/or level of the nitro-containing compound.

23. The method of claim 21, being devoid of deaerating the system.

24. The method of claim 21, wherein the sample comprises oxygen.

25. The method of claim 21, wherein contacting the sample with the sensing electrode comprises contacting an electrolyte solution comprising the sample with the sensing electrode.

26. The method of claim 25, wherein a concentration of dissolved oxygen in said electrolyte is at least 1 ppm.

27. The method of claim 21, wherein said nitro-containing compound is a nitro-containing explosive.

28. A process of preparing the sensing electrode of claim 1, the process comprising:

coupling to a carbon electrode featuring a plurality of a first reactive group on at least a portion of its surface and a compound featuring said functional moiety and a second reactive group that forms a covalent bond with said first reactive group,

thereby preparing the electrode.

29. The process of claim 28, further comprising, prior to said coupling, generating said first reactive group on said at least a portion of said surface of the carbon electrode.

30. The process of claim 29, wherein said generating said reactive groups comprises subjecting the carbon electrode to oxygen plasma treatment.