Preparation Of Microspheric Trans- Aconitic Acid Imprinted Polymer And Its Molecular Recognition Function

Molecular imprinting is a new and potential separation technique for preparing specialized recognition media that is called molecularly imprinted polymer (MIP). The process of the preparation consists of: (1) mixing the template molecule with a functional monomer having complementary functional groups, (2) heat or photo-induced initiation and then polymerization, and (3) extracting the template molecule from the polymer, which leaves cavities inside the polymers that are complementary in terms of size, shape, and functional groups orientation to those of the template molecules. The technique has been applied widely in enantioselective separation, bio- transducer, and simulation of acceptor or antibody, and so on In this thesis, a new method that can be used to synthesize microspheres bearings molecularly imprinted binding sites has been presented. The conventional methods for preparation of MIPs have been simplified by getting rid of the grinding/sieving steps. The destructions of imprinted binding sites and the lost of product in the grinding/sieving steps has been avoided. And the monodisperse molecularly imprinted microspheres maintain similar shape within the binding sites and show stable adsorptive ability towards the template molecule. The molecularly imprinted microspheres are small according to the conventional bulk MIPs so that the target molecules are easy to diffuse in, which strengthens the selective absorption. In our study to a precipitation polymerization method, with acetonitrile as solvent and dispersing medium, trans-aconitic acid as template molecule, monodisperse molecularly imprinted microspheres are synthesized, of which average diameter is 800nm. In molecular recognition analysis, UV spectrometric detection was used. The result shows that the microspheric imprinted polymers had obvious advantages in specific binding to template molecule than the monolithic MIPs. The adsorption to 10-5mol/l trans-aconitic acid by 10mg/ml molecularly imprintedmicrospheres is 78.81%, while adsorption to cis-aconitic acid is 29.75%. Adsorption to trans-aconitic acid by non-molecularly imprinted microspheres is 26.26%.