Metal-coordinated imprinted polymers approach

Molecularly imprinted polymers (MIPs) may be prepared according to a number of approaches that are different in the way the template is linked to the functional monomer and subsequently to the polymeric binding sites (Table 5.1) (see Chapter 4). Thus, the template can be linked and subsequently recognised by virtually any combination of cleavable covalent bonds, metal ion coordination or non-covalent bonds. The first example of molecular imprinting of organic network polymers introduced by Wulff (see Chapter 4) was based on a covalent attachment strategy, i.e. covalent monomer-template, covalent polymer template [1]... 

Arnold and co-workers attempted to prepare imprinted metal-coordinating polymers for proteins [25]. For this purpose, efforts were made to prepare metalcoordinating molecularly patterned surfaces in mixed monolayers spread at the air-water interface or liposomes. This approach was termed as molecular printing and is illustrated in Fig. 6.6. In this process, a protein template is introduced into the aqueous phase, which imposes a pattern of functional amphiphiles in the surfactant monolayer via strong interactions with metal-chelating surfactant head groups. The pattern is then fixed by polymerising the surfactant tails. The technique has also been employed for two dimensional crystallisation of proteins [26]. 

Before the molecularly imprinted polymer may be used for rebinding studies, one step remains—extraction of the original template molecules from the polymer matrix. A number of extraction protocols have been developed for different imprinting procedures. In the covalent and metal coordination approaches, an appropriate reagent is needed to break the bonds formed between the template and the functional elements. For the noncovalent approach, a polar solvent, often... 

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