MIP Sensors on the Way to Real-World Applications - Designing Receptors for the Next Generation of Biosensors - page 165

Fig. 1 General procedure for molecular imprinting
including Van der Waals forces. Covalent imprinting on the other hand relies on
chemically binding the template to the monomer via a functionality that can easily
be cleaved. Non-covalent imprinting is more preferably used for organic molecules
having lower molar masses and sometimes even without pronounced functional
groups, such as organic solvents or anesthetics, but larger species can also be
suitable templates. After polymerization, the template is removed from the poly-
meric matrix by evaporation or washing and thus leaves behind geometrically
adapted cavities and diffusion pathways in the way mentioned before. Surprisingly,
the final polymers can reach similar selectivity and sensitivity as covalently
imprinted ones [ 10 ]. MIPs attract increasing interest, because they combine a
very straightforward synthesis method of an inherently technologically processable
material with outstanding chemical recognition capabilities [ 11 ]. As the analyte
directly influences the generation of cavities in the recognition material, the strat-
egy provides a powerful tool to design highly affine sites even for analytes whose
chemical composition is either not precisely known or that consist of a complex