Fiber optic luminescence-based sensor using metal-organic frameworks for detection of rare earth elements
A system and method for detecting and quantifying the concentration of rare earth elements in a fluid contacting a sensor, the method having the steps of: providing the sensor to an environment such that the sensor is in contact with the fluid, wherein the sensor features a fiber extending between a first end and a second end along a longitudinal axis, wherein the sensor further features a coating on the second end of the fiber, and wherein the coating is a metal-organic framework material including, but not limited to zinc adeninate, 1,3,5-benzenetricarboxylate, 4,4-biphenyldicarboxylate, and combinations thereof; interrogating the sensor with light; collecting a luminescent signal; and detecting the rare earth elements in the fluid contacting the sensor using the luminescent signal.
1 . A method to detect and quantify rare earth elements in a fluid contacting a sensor, comprising:
providing the sensor to an environment such that the sensor is in contact with the fluid, wherein the sensor comprises a fiber extending between a first end and a second end along a longitudinal axis, wherein the sensor further comprises a coating on the second end of the fiber, wherein the coating comprises a metal-organic framework material;
removing the sensor from contact with the fluid and drying the sensor;
interrogating the sensor with light;
collecting a luminescent signal; and
detecting the rare earth elements in the fluid contacting the sensor using the luminescent signal, wherein the fluid comprises a pH less than or equal to about 1, a concentration of non-rare earth element metals at least several orders of magnitude greater than a concentration of rare earth elements therein, or combinations thereof.
2 . The method of claim 1 wherein the metal-organic framework material comprises a crystalline, ordered, highly porous material comprising metal centers linked by organic ligands.
3 . The method of claim 1 wherein the metal-organic framework material comprises zinc adeninate and a polar, aprotic solvent.
4 . The method of claim 3 wherein the metal-organic framework material comprises 1,3,5-benzenetricarboxylate.
5 . The method of claim 3 wherein the metal-organic framework material comprises 4,4-biphenyldicarboxylate.
6 . The method of claim 1 wherein the rare earth element comprises a lanthanide selected from a group consisting of terbium, europium, dysprosium, neodymium, ytterbium, samarium, and combinations thereof.
7 . The method of claim 1 wherein the metal-organic framework material is immobilized on the fiber using a coating procedure selected from the group of coating procedures consisting of sol-gel coating, dipcoating, and combinations thereof.
8 . The method of claim 1 wherein the metal-organic framework comprises pores, and wherein detecting the rare earth elements step comprises encapsulating the rare earth elements in the pores.
9 . The method of claim 8 wherein the method sensitizes the rare earth elements to luminescence-based detection.
10 . The method of claim 1 wherein the luminescent signal is produced by the rare earth element in the fluid upon exposure to light.
11 . The method of claim 1 wherein the luminescent signal is collected downstream from the sensor by a simple optical detector.
12 . The method of claim 1 wherein the method provides a limit of detection of the rare earth elements in the fluid between approximately 60 and approximately 780 parts per billion.
13 . The method of claim 1 wherein the method provides a limit of quantification of the rare earth elements in the fluid between approximately 210 and approximately 2600 parts per billion.
14 . A rare earth element sensor comprising:
a fiber extending between a first end and a second end along a longitudinal axis, wherein the fiber further comprises a coating on the second end of the fiber, wherein the coating is dried prior to interrogation of the sensor with light, and wherein the coating comprises a metal-organic framework material, wherein the metal-organic framework material comprises pores wherein the pores encapsulate excited rare earth elements from a fluid.
15 . The sensor of claim 14 wherein the metal-organic framework material comprises a crystalline, ordered, highly porous material comprising metal centers linked by organic ligands.
16 . The sensor of claim 14 wherein the metal-organic framework material comprises zinc adeninate and a polar, aprotic solvent.
17 . The sensor of claim 14 wherein the metal-organic framework material comprises 1,3,5-benzenetricarboxylate.
18 . The sensor of claim 14 wherein the metal-organic framework material comprises 4,4-biphenyldicarboxylate.
19 . The sensor of claim 14 wherein the fluid comprises a pH less than or equal to about 1.
20 . The sensor of claim 14 wherein the fluid comprises a pH less than or equal to about 1 and a non-rare earth element metal concentration at least several orders of magnitude greater than a rare earth element concentration therein.
21 . The sensor of claim 14 wherein the fluid comprises a pH greater than or equal to about 2 a non-rare earth element metal concentration at least several orders of magnitude greater than a rare earth element concentration therein.