Synthesis of an Enzyme‐like Imprinted Polymer with the Substrate as the Template, and Its Catalytic Properties under Aqueous Conditions

Abstract

Transition state analogues (TSAs) have long been regarded as ideal templates for the preparation of catalytically active synthetic imprinted polymers. In the current work, however, a new type of molecularly imprinted polymer (MIP) was synthesized with the substrate (homovanillic acid, HVA) as the template and hemin introduced as the catalytic center, with the use of plural functional monomers to prepare the active sites. The MIP successfully mimicked natural peroxidase, suggesting that it may not be imperative to employ a TSA as the template when preparing enzyme-like imprinted polymers and that the imprinted polymer matrix provided an advantageous microenvironment around the catalytic center (hemin), essentially similar to that supplied by apo-proteins in natural enzymes. Significantly, by taking advantage of the special structure of hemin and multiple-site interactions provided by several functional monomers, the intrinsic difficulties for MIPs in recognizing template molecules in polar solutions were overcome. The newly developed polymer showed considerable recognizing ability toward HVA, catalytic activity, substrate specificity and also stability, which are the merits lacked by the natural peroxidase. Meanwhile, the ease of recovery and reuse the MIP implies the potential for industrial application.

The First Example of Molecularly Imprinted Nanogels with Aldolase Type I Activity

“…The only examples of catalytic C À C bond formation by imprinted polymers are a Diels-Alder condensation, [4] a Pd-catalysed cross-coupling reaction, [5] an example of class II aldolase [6] and a dimerisation by a peroxidase-like polymer. [7] The development of catalytic microgels, first reported by Resmini et al [8,9] and subsequently by Wulff and his group, [10] represented a significant advance in the field of Abstract: The molecular-imprinting approach was used to obtain a nanogel preparation capable of catalysing the cross-aldol reaction between 4-nitrobenzaldehyde and acetone. A polymerisable proline derivative was used as the functional monomer to mimic the A C H T U N G T R E N N U N G enamine-based mechanism of aldolase type I enzymes.…”

A Molecularly Imprinted Copolymer Designed for Enantioselective Recognition of Glutamic Acid

“…Molecularly imprinted polymers (MIPs, also called artificial receptors or antibodies) that mimic the action of antibodies and enzymes overcome these problems and provide the desirable properties for highly selective molecular recognition, such as durability, specificity, stability at extreme conditions, ease of mass production and low cost. [2][3][4][5] Therefore, MIPs have been applied in separation, [6] artificial antibody mimics, [7,8] catalysis, [9][10][11] sensing devices, [12][13][14][15] and drug delivery. [16] MIPs are frequently prepared with acrylate and vinyl derivatives polymeric materials.…”

“…[16] MIPs are frequently prepared with acrylate and vinyl derivatives polymeric materials. [1,7,[10][11][12]14] Recently, the electrosynthesized polymers such as poly(dopamine) (PDA) and poly(o-phenylenediamine) (Po-PD) have been prepared for obtaining biomimetic recognition matrices. [17][18][19] These polymers are insulating and ultrathin, which are two important desirable features for the design of a MIP capacitive sensor.…”

Temperature-sensitive molecularly imprinted microgels with esterase activity

“…In this context, molecular imprinting technique has been demonstrated to be an attractive strategy for preparing such enzyme mimics. Molecularly imprinted enzyme mimics have been used as the catalysts in a variety of chemical reactions, such as ester hydrolysis, Diels-Alder cycloaddition, elimination, carboncarbon bond formation, redox and hydrogen transfer reactions [3][4][5][6][7][8].…”