ABSTRACT
References .....................................................................................................................................138
Recent years have seen an extensive interest in the field of molecular imprinting [1] where, in
particular, there has been much research activity into analytical separation applications. These
applications include the use of molecularly imprinted polymers (MIPs) as antibody mimics in
pseudo-immunoassay, affinity sorbents in solid-phase extraction (SPE), highly selective stationary
phases in liquid chromatography and capillary electrochromatography, and selective barriers in
chemical sensing. In many cases, MIPs have been shown to give highly competitive, if not
improved, results over traditional materials. The main attraction of the technique is its apparent
simplicity (Figure 5.1). In theory, the synthesis of a polymer in the presence of a template molecule
and subsequent removal of the template creates a robust material with memory sites that have the
ability to selectively rebind the original template from a mixture. In principle, MIPs can be made
with selectivity for essentially any of a diverse range of analyte species such as drug enantiomers,
pesticides, hormones, toxins, short peptides, and nucleic acids. Whereas for biomacromolecules,
antibody technology will in the foreseeable future remain the obvious alternative, molecular
imprinting may offer a viable alternative for small molecules. In these instances, antibody prep-
aration requires conjugation of the hapten to a carrier protein that often changes the structural
properties of the antigen exposed to the immune system. Therefore, the antibodies obtained may be
directed against a structure subtly different to the intended one. In some instances, MIP selectivity
profiles are better than those reported of monoclonal antibodies. MIPs are inherently more robust
than antibodies, and they can be employed for separation of the analyte in matrices ranging from
pure organic solvents to biological fluids.
