Synthesis and characterization of molecularly imprinted polymers for chromatographic separations

The primary objective of this investigation was to discover the optimum solution-phase synthesis conditions for preparing molecularly imprinted polymers (MIPs) against Boc-L-Trp using a binary monomer system. Methacrylic acid (MAA) and 2-vinylpyridine (2-Vpy) were used as the two functional monomers with ethylene glycol dimethacrylate (EGDMA) as the cross-linker. Polymers prepared from two monomers showed improved binding strength and recognition capabilities compared to polymers that were prepared using a single monomer. The synergistic effect on binding was most pronounced for polymers prepared from a starting MAA:2-Vpy molar ratio of about 1:5. A correlation was developed based on molecular interaction scales to relate the template-MIP binding strength to MIP composition. This correlation provides insights on the most important interaction types for the system studied; it also provides an explanation for the improved binding seen with a mixed monomer system. Polymerization temperature and cross-linking density were also investigated for their effects on the MIP recognition properties.