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{{dablink|This article is about polymer chemistry. The term "molecular imprinting" is also used to mean [[Imprinting (genetics)|genetic imprinting]].}}

In [[chemistry]], '''molecular imprinting''' is a technique to create template-shaped cavities in [[polymer]] matrices with memory of the template [[molecule]]s to be used in [[molecular recognition]] <ref name=andersson>''Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003'' Alexander C, Andersson HS, Andersson LI, Ansell RJ, Kirsch N, Nicholls IA, O'Mahony J, Whitcombe MJ J. Mol. Recognit. 2006; 19: 106–180 {{DOI|DOI:10.1002/jmr.760}}</ref>.  This technique is based on the system used by [[enzyme]]s for [[substrate (biochemistry)|substrate]] recognition, which is called the "lock and key" model.  The active binding site of an enzyme has a unique geometric structure that is particularly suitable for a substrate.  A substrate that has a corresponding shape to the site is recognized by selectively binding to the enzyme, while an incorrectly shaped molecule that does not fit the binding site is not recognized.
  
In a similar way, molecularly imprinted materials are prepared using a template molecule and functional [[monomer]]s that assemble around the template and subsequently get crosslinked to each other.  The functional monomers, which are [[self-assembly|self-assembled]] around the template molecule by interaction between [[functional group]]s on both the template and monomers, are polymerized to form an imprinted matrix (commonly known in the scientific community as a molecularly imprinted polymer i.e. MIP).  Then the template molecule is removed from the matrix under certain conditions, leaving behind a cavity complementary in size and shape to the template.  The obtained cavity can work as a selective binding site for a specific template molecule.

[[Image:molecular imprinting.png|center|500px|Preparation of molecularly imprinted material]]

In recent decades, the molecular imprinting technique has been developed for use in [[Receptor (biochemistry)|receptor]]s, [[chromatography|chromatographic separations]], fine chemical sensing, etc. Taking advantage of the shape selectivity of the cavity, use in [[catalysis]] for certain reactions has also been facilitated.

==Early history==
The first example of molecular imprinting is attributed to M.V. Polyakov in 1931. He studied the polymerization of [[sodium silicate]] with [[ammonium carbonate]]. When the polymerization process was accompanied by an additive such as benzene, the silica particles ultimately formed showed a higher uptake of this additive <ref name=andersson/>.

==See also==
*[[molecular recognition]]
*[[Molecular imprinted polymer]]

==References==
{{Reflist}}

[[Category:Polymers]]
[[Category:Supramolecular chemistry]]

[[de:Molecular Imprinting]]
[[Category:2Fix]]