A Connection between the Binding Properties of Imprinted and Nonimprinted Polymers: A Change of Perspective in Molecular Imprinting

Abstract

In the current paradigm about molecular imprinting, the imprinted binding sites exist as a consequence of the polymerization process around templates, and the properties of non-imprinted polymers (NIPs) has been largely overlooked. Thus, nothing can be affirmed a priori on the binding properties of NIPs. We propose an alternative view where the imprinting effect is due to the presence of a template molecule which enhances the pre-existing binding properties of a polymer. If a NIP shows no binding properties towards a target molecule the corresponding imprinted polymer (MIP) will show a weak imprinting effect. On the other hand, if a NIP shows binding properties towards a target molecule, the corresponding MIP will show a significant imprinting effect. To verify this hypothesis we prepared a 96-member combinatorial polymeric library in the absence of any template molecule. This library was screened for several potential ligands and, with no exceptions, the composition of the best binding NIP produced a MIP with excellent binding properties, whereas a low binding NIP formulation produced a MIP with comparable low binding. To validate these results the binding properties towards naproxen and ibuprofen were measured for two combinatorial libraries of polymers, prepared in the presence (MIP-library) and the absence (NIP-library) of the template molecule. The experiment's results showed a correlation between the apparent affinity constant measured for the NIP-and the MIP-library, confirming the proposed hypothesis. Moreover, for closely related molecules, it was shown that binding selectivity is an emergent property derived from the imprinting process, and not a property of NIPs.

Imidazolium-based functional monomers for the imprinting of the anti-inflammatory drug naproxen: Comparison of acrylic and sol–gel approaches

“…However, to the best of our knowledge, this is the first report where such monomer similarity was a primary concern. The search for a suitable functional monomer common to both approaches began with the pyridine core, on the basis of previous works where methacrylic imprints for S-NAP were prepared using vinyl pyridine as functional monomer [21][22][23][24].…”

Development of a novel sensitive molecularly imprinted polymer sensor based on electropolymerization of a microporous-metal-organic framework for tetracycline detection in honey

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A facile approach for synthesizing molecularly imprinted graphene for ultrasensitive and selective electrochemical detecting 4-nitrophenol

“…5, curve c), and the current intensity is only about 8% of that of GR/MIPs modified electrode. The significantly stronger response of GR/MIPs modified electrode toward the template molecule demonstrated that GR/ MIPs composite has a larger number of binding sites than GR/NIPs, which should be attributed to the imprinting effect [33]. In addition, we also compared the DPV current response of GR/MIPs with the control MIPs (Fig.…”