Molecular imprinting

Molecular imprinting is a way of creating recognition sites in polymeric materials. The compound of interest is used as a template. Several variations of the method have been described, in which the recognition sites are prepared in organic polymers, in inorganic materials e.g. silica, or in biomaterials e.g. in protein molecules. The most successful approach though is based on cross-linked organic polymers such as polyacrylates and polystyrenes.

It's just like making a molecular cast.......

The template molecule is dissolved in a solvent together with polymerisable monomers which interact with the template, either via non-covalent interactions (electrostatic interaction, hydrogen bonding, hydrophobic interactions) or via reversible covalent bonds (step 1 in the diagram above).

Next the assembled complex is trapped by polymerising the monomers together with a cross-linking monomer to form a semi-rigid polymer network (step 2).

The template is then extracted from the polymer to leave recognition sites which are complementary in shape and functional groups to the original template (step 3).

Finally, the polymer is applied e.g. in a sensor or in chromatography. Molecules identical to the original template fit into the recognition sites and are bound strongly, while molecules which differ in structure are unable to bind.

We have been working in this area since 1994, and our current interests are in improving the imprinting process by using new monomers and in developing the applications of these materials, particularly in chemical sensors.

Recent publications in this area:

Ramström, O. and Ansell, R.J. Molecular imprinting technology: Challenges and prospects for the future. Chirality, 10, 195-209, 1998.

Ye, L., Ramström, O., Ansell, R.J., Månsson, M.-O. and Mosbach, K. Use of molecularly imprinted polymers in a biotransformation process. Biotechnology & Bioengineering, 64, 650-655, 1999.

Kriz, D. and Ansell, R.J. Biomimetic electrochemical sensors based on molecular imprinting. In: Sellergren, B. (ed.) Molecularly imprinted polymers. Man made mimics of antibodies and their application in analytical chemistry, pp 417-436, Amsterdam, Elsevier Science, 2001.

Ansell, R.J. MIP binding assay - pseudoimmunoassays. Bioseparations, In press, 2001.

Collaborators

Professor Ian A. Nicholls, University of Kalmar, Sweden

Dr. Karsten Haupt, Université Paris XII Val de Marne, France

Other links

The Society for Molecular Imprinting, with its famous database.

Last modified by R. J. Ansell on 23-05-01