Ion-detecting sensors comprising plasticizer-free copolymers
Plasticizer-free ion-detecting sensors for detecting a target ion in a sample are provided. The sensor comprises a plasticizer-free copolymer comprised of polymerized units of methacrylate monomers and a polymerizable ion exchanger, wherein the methacrylated monomers have pendent alkyl groups of different length and wherein the functionalized ion-exchanger is grafted into the copolymer through covalent linkages. The ion exchanger comprises a C-derivative of a halogenated closo-dodecacarborane anion having a polymerizable moiety. Sensors of this invention include carrier-based ion-selective electrodes or optodes such as thin film ion-specific optodes, particle-based optodes, or bulk optodes.
1. An ion-detecting sensor for detecting a target ion in a sample, comprising
(i) a self-plasticizing copolymer matrix comprising polymerized units of methacrylate monomers and an ion exchanger comprising a functionalized C-derivative of a closo-dodecacarborane anion, wherein said functionalized ion exchanger is grafted onto the copolymer through covalent linkages; and
(ii) an ionophore for detecting the target ion,
wherein said methacrylate monomers comprise a monomer having an R 1 pendant alkyl group and a monomer having an R 2 pendant alkyl group, wherein R 1 is any of C 1-3 alkyl groups and R 2 is any of C 4-12 alkyl groups, wherein the self-plasticizing copolymer has a glass transitional temperature (T g ) of about or below 0° C.
2. The ion-detecting sensor of claim 1 , wherein R 1 is any of C 1-2 alkyl groups, and R 2 is any of C 8-12 alkyl groups.
3. The ion-detecting sensor of claim 2 , wherein R 1 is a C 1 alkyl group, and R 2 is a C 10 alkyl group.
4. The ion-detecting sensor of claim 1 , wherein said ion exchanger has the structure:
wherein R 4 is a substituent comprising a double bond.
5. The ion-detecting sensor of claim 4 , wherein R 4 is —O(C═O)CH═CH 2 .
6. The ion-detecting sensor of claim 1 , wherein the matrix is in a form of membrane.
7. The ion-detecting sensor of claim 6 , wherein the ion-detecting sensor is a carrier-based ion-selective electrode.
8. The ion-detecting sensor of claim 6 , wherein the self-plasticizing copolymer matrix and ionophore is in the form of a membrane for a thin film ion-specific optode.
9. The ion-detecting sensor of claim 6 , wherein the self-plasticizing copolymer matrix and ionophore is in the form of a membrane for a bulk optode.
10. The ion-detecting sensor of claim 1 , wherein the polymer is in a form of particles.
11. The ion-detecting sensor of claim 10 , wherein the self-plasticizing copolymer matrix and ionophore is in the form of particles for a particle-based optode.
12. The ion-detecting sensor of claim 1 , wherein said ionophore is selective for calcium ions.
13. The ion-detecting sensor of claim 1 , further comprising an indicator ionophore.
14. The ion-detecting sensor of claim 13 , wherein the indicator ionophore is selected from a group consisting of a pH indicating chromoionophore, a chromoionophore, a fluoroionophore, a pH indicator, and a pH indicating fluoroionophore.
15. The ion detective sensor of claim 1 , wherein the target ion selected from a group consisting of H + , Li + , Na + , K + , Ca 2+ , and Mg 2+ .
16. The ion-detecting sensor of claim 1 , comprising a sample, wherein the sample is a body fluid selected from the group consisting of whole blood, spinal fluid, blood serum, urine, saliva, semen, and tears.
17. The ion-detecting sensor of claim 1 , wherein said copolymer is blended with poly(vinyl chloride) and a plasticizer.
18. The ion-detecting sensor of claim 1 , wherein said ionophore is a functionalized ionophore.
19. The ion-detecting sensor of claim 18 , wherein at least a portion of the functionalized ionophore is grafted onto the copolymer through covalent linkage.
20. The ion-detecting sensor of claim 18 , wherein said functionalized ionophore is a hydrophilic crown ether.
21. The ion-detecting sensor of claim 20 , wherein said crown ether is 4′-acryloylamidobenzo-15-crown-5 or 4′-acyloylamidobenzo-18-crown-6.
22. An ion-detecting sensor for detecting a target ion in a sample, comprising
(i) a self-plasticizing copolymer matrix comprising polymerized units of methacrylate monomers and an ion exchanger comprising a functionalized C-derivative of a closo-dodecacarborane anion, wherein said functionalized ion exchanger is grafted onto the copolymer through covalent linkages; and
(ii) an ionophore for detecting the target ion,
wherein said methacrylate monomers have R 1 or R 2 pendant alkyl groups wherein R 1 is any of C 1-3 alkyl groups and R 2 is any of C 4-12 alkyl groups, wherein at least a portion of the functionalized ionophore is grafted onto the copolymer through covalent linkage, wherein said functionalized ionophore is
wherein R 3 is a substituent comprising an unsaturated group.
23. An ion-detecting sensor of claim 22 wherein R 3 is —O(C═O)CH═CH 2 .
24. A ion-detecting sensor for detecting a target cation in a sample, comprising an ion exchanger covalently grafted into a self-plasticizing co-polymer, and an ionophore for detecting the target ion, wherein said ion exchanger is a derivative of a halogenated carborane anion having a polymerizable moiety, wherein said co-polymer comprises methacrylate monomers, wherein said methacrylate monomers comprise a monomer having an R 1 pendant alkyl group and a monomer having an R 2 pendant alkyl group, wherein R 1 is any of C 1-3 alkyl groups and R 2 is any of C 4-12 alkyl groups, wherein the self-plasticizing copolymer has a glass transitional temperature (T g ) of about or below 0° C.
25. An ion-detecting sensor for detecting a target cation in a sample, comprising a polymerizable ion exchanger covalently grafted into a self-plasticizing co-polymer, and an ionophore for detecting the target ion, wherein said co-polymer comprises methacrylate monomers, wherein said methacrylate monomers comprise a monomer having an R 1 pendant alkyl group and a monomer having an R 2 pendant alkyl group, wherein R 1 is any of C 1-3 alkyl groups and R 2 is any of C 4-12 alkyl groups, wherein said polymerizable ion exchanger has the structure:
wherein R 4 is a substituent comprising a double bond, wherein the self-plasticizing copolymer has a glass transitional temperature (T g ) of about or below 0° C.
26. The ion-detecting sensor of claim 25 , wherein R 4 is —O(C═O)CH═CH 2 .
27. A method of preparing a plasticizer-free co-polymer responsive to a target ion, comprising:
(a) combining:
(i) methacrylate monomers, wherein said methacrylate monomers comprise a monomer having an R 1 pendant alkyl group and a monomer having an R 2 pendant alkyl group, wherein R 1 is any of C 1-3 alkyl groups and R 2 is any of C 4-12 alkyl groups;
(ii) an ion exchanger comprising a functionalized C-derivative of a closo-dodecacarborane anion having a polymerizable moiety;
(iii) an ionophore selective for said target ion;
(iv) a cross-linking monomer; and
(v) a polymerization initiator; and
(b) treating said combination under conditions that allow said methacrylate monomers and said closo-dodecacarborane anion to copolymerize, wherein the co-polymer has a glass transitional temperature (T g ) of about or below 0° C.
28. The method of claim 27 , wherein said closo-dodecacarborane anion has the structure
wherein R 4 is a substituent comprising a double bond.
29. The method of claim 28 , wherein R 4 is —O(C═O)CH═CH 2 .
30. The method of claim 27 further comprising blending said copolymer with poly(vinyl chloride) and a plasticizer.
31. The method of claim 27 , wherein R 1 is any of C 1-2 alkyl groups and R 2 is any of C 8-12 alkyl groups.
32. The method of claim 27 , wherein said ionophore is a functionalized ionophore.
33. The method of claim 32 wherein said functionalized ionophore has the structure:
wherein R 3 is a substituent comprising an unsaturated group.
34. The method of claim 33 , wherein R 3 is —O(C═O)CH═CH 2 .
35. The method of claim 32 , wherein said functionalized ionophore is a hydrophilic crown ether.
36. The method of claim 35 , wherein said crown ether is 4′-acryloylamidobenzo-15-crown-5 or 4′-acyloylamidobenzo-18-crown-6.
37. The method of claim 32 , wherein at least of portion of said ionophore is grafted onto the copolymer.
38. A plasticizer-free co-polymer prepared by the method of claim 27 .
39. A sensor comprising a plasticizer-free co-polymer prepared by the method of claim 27 , and an ionophore, wherein the ionophore is selective for a target ion.
40. A graft self-plasticizing copolymer having selectivity for a target ion, comprising (i) a copolymer comprising polymerized units of methacrylate monomers; (ii) an ionophore selective for the target ion; and (iii) an ion exchanger comprising a C-derivative of a closo-dodecacarborane anion having a polymerizable moiety, wherein ion exchanger is grafted onto the copolymer through covalent linkages, wherein the graft self-plasticizing copolymer has a glass transitional temperature (T g ) of about or below 0° C.
41. The graft copolymer of claim 40 , wherein said ion exchanger has the structure:
wherein R 4 is a substituent comprising a double bond.
42. The graft copolymer of claim 41 , wherein R 4 is —O(C═O)CH═CH 2 .
43. The graft copolymer of claim 40 , wherein said ionophore is a functionalized ionophore.
44. The graft copolymer of claim 43 , wherein said functionalized ionophore is a hydrophilic crown ether.
45. The graft copolymer of claim 43 , wherein at least a portion of said ionophore is grafted onto the copolymer.
46. A graft self-plasticizing copolymer having selectivity for a target ion, comprising (i) a copolymer comprising polymerized units of methacrylate monomers; (ii) an ionophore selective for the target ion; and (iii) an ion exchanger comprising a C-derivative of a closo-dodecacarborane anion having a polymerizable moiety, wherein ion exchanger is grafted onto the copolymer through covalent linkages, wherein said ionophore is a functionalized ionophore, wherein said ionophore has the structure:
wherein R 3 is a substituent comprising an unsaturated group.
47. The graft copolymer of claim 44 , wherein said ionophore is 4′-acryloylamidobenzo-15-crown-5.
48. The graft copolymer of claim 44 , wherein said ionophore is 4′-acryloylamidobenzo-18-crown-6.