Semi-covalent surface molecular imprinting of polymers by one-stage mini-emulsion polymerization: glucopyranoside as a model analyte.

This paper describes a new type of surface imprinting technique that combines the advantages of both the semi-covalent approach and one-stage miniemulsion polymerization. This process has been successfully applied for the preparation of glucose surface-imprinted nanoparticles. The selective artificial receptors for glucopyranoside were fully characterized by IR, TEM and BET analyses, and their molecular recognition abilities by binding experiments carried out in batch processes. The molecular affinity and selectivity of the glucose molecularly imprinted polymers were accurately quantified. These characteristics are essential for verification of the efficiency of the developed surface imprinting process. The imprinting effect was clearly demonstrated using the batch rebinding method. We have found that the glucose imprinted polymers produced using the optimized one-stage mini-emulsion exhibited quite fast kinetics of binding and equilibration with glucopyranoside templates, compared to polymers prepared by bulk polymerization technique, as well as extremely low levels of unspecific bindings. We also demonstrated that glucose molecular imprinted polymer (MIP) exhibited very good selectivity for its original template compared to other glycopyranoside derivatives, such as galactose. Finally, the extraction of the binding properties from isotherms of binding by fitting to the bi-Langmuir and Freundlich models allowed the determination of the affinity constant distribution of the binding sites. This imprinting protocol allowed the determination of an affinity constant (K(D)), involving exclusively H-bonding interactions, for the glucose MIP (P2C) with the best template 1, in CH3CN as the solvent system.