Molecularly Imprinted Polymer Sensing Method

Abstract

A method for detecting a taggant molecular structure in a fluid includes providing a molecularly imprinted polymer sensor device, contacting a molecularly imprinted crosslinked star polymer with the fluid, and correlating a color change in the fluid with the amount of the taggant molecular structure in the fluid. The device has polymer arms attached to a core, and the core has molecular sized cavities adapted to selectively receive and bind displacement molecules having the taggant molecular structure and a colorimetric indicator. The displacement molecule is selectively removed from the molecularly imprinted crosslinked polymer upon exposure to the taggant molecular structure in the fluid thereby indicating the presence of the taggant molecular structure in the fluid based on a loss of color along a length of a housing.

1 . A method for detecting the presence of a taggant molecular structure in a fluid, the method comprising:
 (a) providing a molecularly imprinted polymer sensor device for detecting the presence of a taggant molecular structure in a fluid, said device comprising a molecularly imprinted crosslinked polymer having a crosslinked core and a plurality of polymer arms attached to the core, wherein the core has molecular sized cavities adapted to selectively receive and bind displacement molecules having the taggant molecular structure and a colorimetric indicator;   (b) contacting the molecularly imprinted crosslinked star polymer with the fluid, wherein said displacement molecule is selectively removed from the molecularly imprinted crosslinked polymer upon exposure to the taggant molecular structure in the fluid thereby indicating the presence of the taggant molecular structure in the fluid based on a loss of color along a length of a housing; and   (c) correlating a color change in the fluid with the amount of the taggant molecular structure in the fluid.   
     
     
         2 . The method of  claim 1 , wherein the taggant molecular structure is selected from the group consisting of a hormone, a drug and a drug residue. 
     
     
         3 . The method of  claim 2 , wherein the hormone is cortisol. 
     
     
         4 . The method of  claim 3 , wherein the fluid is a biological fluid. 
     
     
         5 . The method of  claim 4 , wherein the biological fluid is saliva or blood. 
     
     
         6 . The method of  claim 2 , wherein the drug is selected from the group consisting of gamma hydroxybutyric acid, flunitrazepam, ketamine, gamma-hydroxybutyrate (GHB), gamma butyrolactone (GBL) and mixtures thereof. 
     
     
         7 . The method of  claim 6 , wherein the fluid is a beverage. 
     
     
         8 . The method of  claim 1 , wherein the housing comprises an inlet for receiving the fluid, the inlet having a coating on at least a portion of the inside of the surface thereof, the coating comprising the molecularly imprinted crosslinked polymer. 
     
     
         9 . The method of  claim 8 , wherein the housing is a capillary tube. 
     
     
         10 . The method of  claim 3 , wherein the colorimetric indicator is methylene blue. 
     
     
         11 . The method of  claim 6 , wherein the colorimetric indicator is methylene blue. 
     
     
         12 . The method of  claim 1 , wherein the molecularly imprinted crosslinked polymer is prepared by:
 (a) reacting at least one functional monomer and a Reversible Addition Fragmentation Chain Transfer (RAFT) agent in the presence of an initiator;   (b) crosslinking the product of step (a) with a crosslinking agent and the taggant molecular structure in the presence of a Grubb catalyst under olefin metathesis reaction conditions to form a molecularly imprinted crosslinked polymer containing the taggant molecular structure;   (c) removing the taggant molecular structure from the molecularly imprinted crosslinked polymer; and   (d) incorporating the displacement molecules into the molecularly imprinted crosslinked polymer.