Surrogate Imprinting Strategies: Molecular Imprints via Fragments and Dummies

Abstract

There is an increasing need to selectively bind, determine, preconcentrate, or filter compounds frequently present at very low concentration levels in a wide variety of complex matrices. Among other strategies, this need has been addressed by MIPs serving as tailorable synthetic molecular recognition motifs. While the generation of MIPs appears synthetically straightforward, their preparation for the determination of toxic, infectious, rare, or unstable species remains a challenge due to the requirement of using the target species as the actual template during synthesis. A viable alternative is, therefore, replacing the target/template by an appropriate surrogate emulating its size, shape, and surface functionality. Functional polymer materials mimicking biological recognition processes are highly relevant and a vital research field with molecularly imprinted materials at the forefront of this development. Next to the fundamental scientific aspects related to these materials, their practical relevance is reflected in a plethora of applications ranging from biomimetic sensors and assays to selective preconcentration and filtration taking advantage of their selective recognition properties. This review aims to highlight recent advances and innovative strategies toward the development of polymers with selective recognition properties prepared via surrogate templates. Advantages and disadvantages of these strategies are discussed and contrasted by selected examples highlighting the features of such materials addressing specifically such delicate templates.

The Evolution of Molecular Recognition: From Antibodies to Molecularly Imprinted Polymers (MIPs) as Artificial Counterpart

“…Moreover, surface-imprinted materials have recognition sites on the polymeric surface [ 110 ] and exhibit an enhanced selectivity and sensitivity [ 126 ] improving recognition effectiveness. They are produced by localizing the template on the polymeric surface [ 127 ] and the most frequently employed techniques are the solid-phase approach and emulsion polymerization [ 128 , 129 ].…”

Development and Characterization of Magnetic SARS-CoV-2 Peptide-Imprinted Polymers

“…Thus, due to the polymerization reaction being carried out in the presence of the template molecule, the selection of the polymerization method, including the reaction conditions such as temperature and solvents, is crucial because these variables strongly affect not only the morphology and size of the final polymer but also the imprinting effect. The template can be the target (bio)molecule itself, a part or fragment of the target, or even another structurally and chemically similar compound (i.e., surrogate) [16]. Considering the experimental problems associated with the use of infectious biological species such as viruses as the template during the polymerization step, fragment imprinting is one of the most interesting and attractive strategies.…”

“Out of Pocket” Protein Binding—A Dilemma of Epitope Imprinted Polymers Revealed for Human Hemoglobin

“…The concentration of HbA and HbA1c in blood are routinely measured for the determination of the degree of glycated HbA-the long-term diabetic parameter [6]. Recently MIP based sensors which apply the whole spectrum of electrochemical and optical transducers made inroads in the determination of protein biomarkers [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] including SARS-COV-2 antigens [8]. For many years, Bülow's group made great efforts to create HbA-specific polymer beads for chromatographic separation of HbA variants from protein mixtures and crude cell 2 of 13 extracts [27][28][29].…”