Molecularly imprinted polymers: present and future prospective

Abstract

Molecular Imprinting Technology (MIT) is a technique to design artificial receptors with a predetermined selectivity and specificity for a given analyte, which can be used as ideal materials in various application fields. Molecularly Imprinted Polymers (MIPs), the polymeric matrices obtained using the imprinting technology, are robust molecular recognition elements able to mimic natural recognition entities, such as antibodies and biological receptors, useful to separate and analyze complicated samples such as biological fluids and environmental samples. The scope of this review is to provide a general overview on MIPs field discussing first general aspects in MIP preparation and then dealing with various application aspects. This review aims to outline the molecularly imprinted process and present a summary of principal application fields of molecularly imprinted polymers, focusing on chemical sensing, separation science, drug delivery and catalysis. Some significant aspects about preparation and application of the molecular imprinting polymers with examples taken from the recent literature will be discussed. Theoretical and experimental parameters for MIPs design in terms of the interaction between template and polymer functionalities will be considered and synthesis methods for the improvement of MIP recognition properties will also be presented.

Keywords: HPLC; artificial receptors; catalysis; drug delivery; molecular imprinting technology (MIT); molecular recognition; molecularly imprinted polymers (MIPs); sensors; solid phase extraction.

Figure 1

Scheme of molecular imprinting.

Figure 2

Schematic representation of molecular imprinting of tri-O-acetyladenosine (TOAA) using Zn(II) tetra(4′-methacryloyloxyphenoxy)phthalocyanine 1 and methacrylic acid (Adapted from [27]).

Figure 3

The most stable prepolymerization complex structures for a ratio of 1:2, 1:3 and 1:4 between nicotinamide and methacrylic acid (Adapted from [40]).

Figure 4

Structure of the most common monomers used for molecular imprinting.

Figure 5

Structure of the most common cross-linkers used for molecular imprinting.

Figure 6

The four steps of the MISPE process.

Figure 7

Chromatograms corresponding to (a) human urine; (b) human urine spiked with 1-MA; and (c) elution solution after MISPE of spiked urine. Peak identification:1, 1-MA (Adapted from [54]).

Figure 8

MIP catalytic systems developed by Beach and Shea (Adapted from [170]).