Molecularly Imprinted Polymers*

Abstract

Molecularly imprinted polymers (MIPs) are man-made polymeric materials with molecular recognition abilities. The polymers mimic the molecular recognition of natural molecular recognition elements, such as receptors and antibodies, by binding target molecules in a highly selective manner. The interactions between MIPs and their targets are of non-covalent or covalent nature, or a mixture thereof. Furthermore, metal ion mediated recognition can be applied to target molecules carrying chelating moieties. The recognition of MIPs originates from the spatial orientation and fixation of polymer building blocks (i.e., monomers and cross-linkers) around a template during the polymerization. MIPs have traditionally been synthesized as monolithic polymers that are ground and sieved to an appropriate size fraction. More recently, methods to synthesize MIPs in the shape of spherical beads have been reported. Films and membranes are other attractive formats of MIPs. The design of MIPs involves a large number of variables, such as the choice of monomers and cross-linkers and their molar ratios. Statistical experimental design, multivariate data analysis, and computational approaches are valuable tools in the optimization of the MIP formulation. Characterization of MIPs includes evaluation of the binding as well as the physical properties. The applications of MIPs are exemplified by their use in chromatography and solid-phase extraction, sorbent assays, sensors, and catalysis. (Less)