Molecularly imprinted carbon
Preparation of a molecularly imprinted carbon is described. The molecularly imprinted carbon has a surface that is imprinted on the molecular level for a specific template molecule of interest, making it highly selective for analytes corresponding to at least a portion of the template molecule. Devices including the molecularly imprinted carbon and their use in methods of detecting analytes are also described. As an example, dibutyl butylphosphonate (DBBP), a surrogate for chemical warfare agents, was used as a template molecule. Electrospun molecularly imprinted SU-8 and pyrolyzed polymer (PP) solid-phase microextraction (SPME) devices were prepared; their ability to preferentially extract DBBP from an aqueous matrix, with and without interferences present, was evaluated via comparison with non-imprinted SU-8 and PP SPME fibers. The electrospun devices demonstrated a higher selectivity for DBBP, as evidenced by their extraction time profiles. The MI-SPME fibers tested extracted at least 60% more DBBP than their non-imprinted counterparts.
1. A composition comprising a nongraphitizable molecularly imprinted carbon derived from a molecularly imprinted polymer; wherein a portion of the molecularly imprinted carbon has a shape corresponding to the shape of at least a portion of a template molecule; and wherein the molecularly imprinted carbon has an affinity for the template molecule, wherein the molecularly imprinted carbon is formed by pyrolysis of the molecularly imprinted polymer in an inert or reducing atmosphere.
2. The composition of claim 1 , wherein the molecularly imprinted polymer comprises a polymer selected from the group consisting of: cellulose, poly(furfuryl alcohol) or a furfuryl alcohol copolymer, poly(vinylidene chloride), resorcinol-phenol copolymer, highly unsaturated polymers, polyimide, and polyacrylonitrile.
3. The composition of claim 1 , wherein the molecularly imprinted polymer comprises a photoresist polymer.
4. The composition of claim 3 , wherein the photoresist polymer is an epoxy-based negative photoresist.
5. The composition of claim 4 , wherein the polymer is SU-8.
6. The composition of claim 1 , wherein the molecularly imprinted polymer is imprinted by the template molecule, wherein the template molecule has a size of 1 micron or less.
7. A solid phase microextraction device comprising a solid support, at least a portion of a surface of the solid support carrying a layer thereon, wherein the layer comprises the composition of claim 1 .
8. The composition of claim 1 , wherein the molecularly imprinted carbon has greater affinity for the template molecule than does the molecularly imprinted polymer.
9. The composition of claim 1 , wherein the composition is a coating.
10. A composition comprising a nongraphitizable molecularly imprinted carbon; wherein a portion of the molecularly imprinted carbon has a shape corresponding to the shape of at least a portion of a template molecule; wherein the molecularly imprinted carbon has an affinity for the template molecule; wherein the nongraphitizable molecularly imprinted carbon is produced by:
applying a mixture including a cross-linkable base polymer and a template molecule to at least a portion of a surface of a solid support;
crosslinking the base polymer to form a molecularly imprinted polymer;
extracting the template molecule from the molecularly imprinted polymer, and
pyrolyzing the molecularly imprinted polymer in an inert or reducing atmosphere to form the nongraphitizable molecularly imprinted carbon.
11. The device of claim 7 , wherein the solid support comprises stainless steel wires.
12. the device of claim 7 , wherein the molecularly imprinted carbon has a first portion having a shape corresponding to the shape of at least a portion of a first template molecule, and a second portion having a shape corresponding to at least a portion of a second template molecule.