Application of non-specific fluorescent dyes for monitoring enantio-selective ligand binding to molecularly imprinted polymers

The displacement of non-specific dyes from molecularly imprinted polymer (M IP) chromatographic stationary phases has been used for the detection and q uantification of ligand-polymer binding events. A blank polymer and an L-ph enylalaninamide-imprinted polymer were prepared using methacrylic acid as t he functional monomer and ethylene glycol dimethacrylate as a crosslinker. The MIP is first loaded with dye, and a solution of the dye in the eluent i s passed through the MIP. If analyte is injected into the dye solution in t he eluent, part of the dye is competitively replaced by the analyte from th e MIP. Specifically, the competitive displacement of rhodamine B by amino a cids and phenylalaninamide (Phe-NH2), respectively, has been studied under polar and hydrophobic elution conditions. Enantioselective binding of Phe a nd Phe-NH2 to the imprinted polymer was shown to occur in the micromolar co ncentration range. It is proposed that the displacement of non-specific dye s from MIPs be used for the development of multisensors based upon these hi ghly specific and stable materials, which provide promising alternatives to the use of biological macromolecules in sensor technology.