Role of Comonomers in the Recognition of Anionic Biomolecules in Water: Hydrogen-Bonded Imprinted Polymeric Receptor

The field of anion recognition in aqueous media is dominated by multiple positive charges and/or metal ions containing synthetic receptors. Here, we report the synthesis of a highly water-compatible oxyanion-imprinted neutral receptor by cross-linking the polymerizable diaryl urea host monomer and phenyl phosphonic acid (PPA) complex in the presence of a large number of comonomers containing hydroxyl or methyl ester groups. We have demonstrated that the affinity of the imprinted receptor for anions is easily tuned by decorating the hydrophilic and hydrophobic end groups around the binding pocket of the imprinted receptor. The binding characteristics of the synthesized artificial binders were evaluated in aqueous and nonaqueous environments. We have demonstrated practical applicability of the PPA-imprinted receptor by packing in the solid-phase extraction cartridge which was used to separate the ubiquitous pesticide glyphosate from water. Also, the developed receptor can selectively bind to phosphorylated tyrosine amino acids and phosphorylated tyrosine octapeptides in aqueous buffered media than to other phosphorylated and nonphosphorylated analogues. The approach utilized here to use an inexpensive dummy template can be utilized for the synthesis of imprinted receptors for anions with phosphate motifs.