Lead ion sensors, methods of making and uses thereof
View Patent ↗Copolymers including at least one optionally substituted 2-hydroxy-5-sulfonic aniline as a first constituent unit and at least one optionally substituted phenylenediamine as a second constituent unit are disclosed. Compositions containing the copolymers, and methods of making the copolymers are also disclosed. The compositions can also contain for example an ethylene-vinyl acetate copolymer (EVA) and/or electrical conducting additives. The compositions can, for example, be used for detecting lead ions in a sample.
1. A copolymer comprising at least one optionally substituted 2-hydroxy-5-sulfonic aniline as a first constituent unit and at least one optionally substituted phenylenediamine as a second constituent unit, wherein the first constituent unit is present in the copolymer in an amount of about 5% to about 10% by mole and the second constituent unit is present in the copolymer in an amount of about 90% to about 95% by mole, and wherein particles of the copolymer have an average diameter of about 2000 nm.
2. The copolymer of claim 1 , wherein the first constituent unit is represented by Formula I:
wherein R 1 is hydrogen or an electron-donating group, and R 2 is hydrogen or an electron-donating group.
3. The copolymer of claim 2 , wherein R 1 is —CH 3 , —NH 2 , —NHC(O)OCH 2 CH 3 , or hydrogen.
4. The copolymer of claim 2 , wherein the electron-donating group is C 1-6 alkyl, C 1-6 alkoxy, —OH, an amino group, C 1-6 hydroxyalkyl, C 1-6 alkylthio, or a carbamate.
5. The copolymer of claim 1 , wherein the second constituent unit is represented by Formula II:
wherein Z 1 , Z 2 , and Z 3 are each independently hydrogen or an electron-donating group.
6. The copolymer of claim 5 , wherein Z 1 is hydrogen, —NH 2 , —CH 3 , —OH, —OCH 3 , or —CH 2 OH.
7. The copolymer of claim 5 , wherein Z 2 is hydrogen, —OCH 3 , or —SCH 3 .
8. The copolymer of claim 5 , wherein Z 3 is hydrogen, —OCH 3 , or —CH 3 .
9. The copolymer of claim 1 , wherein the second constituent unit is represented by Formula III, Formula IV, or Formula V:
wherein G 1 and G 2 are each independently hydrogen or an electron-donating group.
10. The copolymer of claim 9 , wherein G 1 and G 2 are each independently hydrogen or methoxy.
11. The copolymer of claim 1 , wherein the copolymer has a molar ratio of the first constituent unit to the second constituent unit of about 5:95.
12. A polymeric membrane for ion sensitive measurement comprising an ethylene-vinyl acetate copolymer (EVA) and one or more ionophores that are selective toward lead ions, wherein the one or more ionophores include particles of a copolymer having at least one optionally substituted 2-hydroxy-5-sulfonic aniline as a first constituent unit and at least one optionally substituted phenylenediamine as a second constituent unit, wherein the first constituent unit is present in the copolymer in an amount of about 5% to about 10% by mole and the second constituent unit is present in the copolymer in an amount of about 90% to about 95% by mole, and wherein the particles of the copolymer have an average diameter of about 2000 nm.
13. The polymeric membrane of claim 12 , wherein the first constituent unit is represented by Formula I:
wherein R 1 is hydrogen or an electron-donating group, and R 2 is hydrogen or an electron-donating group.
14. The polymeric membrane of claim 13 , wherein R 1 is —CH 3 , —NH 2 , —NHC(O)OCH 2 CH 3 , or hydrogen.
15. The polymeric membrane of claim 13 , wherein the electron-donating group is C 1-6 alkyl, C 1-6 alkoxy, —OH, an amino group, C 1-6 hydroxyalkyl, C 1-6 alkylthio, or a carbamate.
16. The polymeric membrane of any one of claim 12 , wherein the second constituent unit is represented by Formula II
wherein Z 1 , Z 2 , and Z 3 are each independently hydrogen or an electron-donating group.
17. The polymeric membrane of claim 16 , wherein:
Z 1 is hydrogen, —NH 2 , —CH 3 , —OH, —OCH 3 , or —CH 2 OH; or
Z 2 is hydrogen, —OCH 3 , or —SCH 3 ; or
Z 3 is hydrogen, —OCH 3 , or —CH 3 .
18. The polymeric membrane of claim 12 , wherein the second constituent unit is represented by Formula III, Formula IV, or Formula V:
wherein G 1 and G 2 are each independently hydrogen or an electron-donating group.
19. The polymeric membrane of claim 18 , wherein G 1 and G 2 are each independently hydrogen or methoxy.
20. The polymeric membrane of claim 12 , wherein the polymeric membrane comprises the one or more ionophores in an amount of about 0.1% to about 10% by weight.
21. The polymeric membrane of claim 12 , wherein the polymeric membrane comprises the one or more ionophores in an amount of about 4.5% by weight.
22. The polymeric membrane of claim 12 , wherein the polymeric membrane comprises one or more ion exchangers.
23. The polymeric membrane of claim 22 , wherein the polymeric membrane comprises the one or more ion exchangers in an amount of about 0% to about 8% by weight.
24. The polymeric membrane of claim 22 , wherein the one or more ion exchangers are sodium tetraphenylborate (NaTPB), potassium tetraphenylborate (KTPB), potassium tetrakis(4-chlorophenyl)]borate (KTClPB), potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (KTFPB), sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaTFPB), or combinations thereof.
25. The polymeric membrane of claim 12 , wherein the polymeric membrane has an average thickness of about 30 μm to about 400 μm.
26. The polymeric membrane of claim 12 , wherein the polymeric membrane comprises one or more electrical conducting additives.
27. The polymeric membrane of claim 26 , wherein the one or more electrical conducting additives comprise a conducting polymer, metal nanoparticles, a graphene nanosheet, a carbon nanotube, carbon black, polyaniline nanosticks, or any combination thereof.
28. The polymeric membrane of claim 27 , wherein the conducting polymer comprises polyaniline, polypyrrole, polythiophene, polyacetylene, poly(3,4-ethylenedioxythiophene), poly(3-octylthiophene), or any combination thereof.
29. The polymeric membrane of claim 12 , wherein the polymeric membrane is substantially plasticizer free.
30. A sensor for measuring lead ions, the sensor comprising: a lead ion-selective electrode, wherein the lead ion-selective electrode comprises a polymer matrix and particles of a copolymer, wherein the copolymer comprises at least one optionally substituted 2-hydroxy-5-sulfonic aniline as a first constituent unit and at least one optionally substituted phenylenediamine as a second constituent unit, wherein the first constituent unit is present in the copolymer in an amount of about 5% to about 10% by mole and the second constituent unit is present in the copolymer in an amount of about 90% to about 95% by mole, and wherein the particles of the copolymer have an average diameter of about 2000 nm.
31. The sensor of claim 30 , wherein the sensor further comprises a reference electrode.
32. A method for detecting lead ions in a sample, the method comprising: providing a sample suspected of containing one or more lead ions;
contacting the sample with a sensor, wherein the sensor comprises a reference electrode and a lead ion-selective electrode, wherein the lead ion-selective electrode comprises a polymer matrix and one or more ionophores selective for lead ions, wherein the one or more ionophores comprise particles of a copolymer comprising at least one optionally substituted 2-hydroxy-5-sulfonic aniline as a first constituent unit and at least one optionally substituted phenylenediamine as a second constituent unit, wherein the first constituent unit is present in the copolymer in an amount of about 5% to about 10% by mole and the second constituent unit is present in the copolymer in an amount of about 90% to about 95% by mole, wherein the particles of the copolymer have an average diameter of about 2000 nm; and
measuring an electromotive force (EMF) between the reference electrode and the lead ion-selective electrode.
33. The method of claim 32 , wherein the sensor is potentiometric and functions substantially logarithmically.
34. The method of claim 32 , wherein the concentration of lead ions in the sample correlates with the EMF measured.
35. The method of claim 32 , wherein the measured EMF is greater in the presence of the lead ions than in the absence of the lead ions.
36. The method of claim 32 , wherein the concentration of the lead ions in the sample is about 10 −3 M to about 10 −7 M.
37. The method of claim 32 , wherein the sample is contacted with the sensor for no more than about 10 minutes.
38. The method of claim 32 , wherein the sample is contacted with the sensor for no more than about 60 seconds.