molecular imprinting (rus. молекулярный импринтинг) — a technique to create "molecular imprints" that involves polymerisation of functional monomers in an environment containing specially injected target template molecules.

Description

One of the major requirements applied to sorbent materials used for analytical purposes is the high selectivity of such materials. In general, this selectivity is achieved through the development in a polymer of functional groups characterised by the selective sorption of certain substances or, for immunosorbents, through the injection of antibodies into the polymer. However, the synthesis of such polymers is a very expensive process, and in some cases selection of an appropriate functional group or antibody enabling the effective sorption of the target substance appears impossible. One effective solution is to develop highly selective sorbents based on polymer systems capable of nano-level "structural adjustment" to the target sorbate. Such systems include polymers with "molecular imprints" obtained using the molecular imprinting technique.

The process of creating polymers with "molecular imprints" involves three stages. At the initial stage, a monomer and molecular template are mixed together in an appropriate solvent until polymerisation occurs. This stage involves the so-called pre-organisation – development of a stable pre-polymerisation combination of the monomer and template substance molecules implying proper arrangement of functional monomer molecules and their attachment to the template molecules. At the second stage, polymerisation or polycondensation of pre-polymerised combinations with an excessive amount of linking agent results in the development of a tightly cross-linked polymer with a rigid structure.

At the third stage, the polymer is reduced and sieved to the required particle size, after which the molecular template is removed from the polymer network. This process results in the generation of cavities (pores) in the material; these cavities are three-dimensional imprints theoretically capable of specific complementary interactions with target template molecules or compounds with equivalent structure. Complementarity is defined as the correspondence of an imprint to the template in terms of shape and size, as well as in terms of presence in the imprint of complementary functional groups capable of interacting with the functional groups of a template molecule. Thus, the capability of molecular-imprinted polymers for recognition is based on the correspondence of the shape of imprints and specific functional groups comprising such imprints to the template molecules.

Depending on the type of bond (covalent or noncovalent) between the molecules of monomer and template, the imprinting process may be covalent or noncovalent.

Author

  • Goldt Ilya V.

Sources

  1. Lisichkin G. V., Krutyakov Yu. A. Molecularly imprinted materials: synthesis, properties, applications (in Russian) // Russian Chemical Reviews 75 (10), pp. 901-918.
  2. Hendrickson O.D., Zherdev A.V., Dzantiev B.B. Molecularly imprinted polymers and thei application in biochemical analysis (in Russian) // Uspekhi biologicheskojj khimii V. 46, 2006. P. 149–192.

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