We report an approach integrating the synthesis of protein‐imprinted nanogels (“plastic antibodies”) with a highly sensitive assay employing templates attached to magnetic carriers. The enzymes trypsin and pepsin were immobilized on amino‐functionalized solgel‐coated magnetic nanoparticles (magNPs). Lightly crosslinked fluorescently doped polyacrylamide nanogels were subsequently produced by high‐dilution polymerization of monomers in the presence of the magNPs. The nanogels were characterised by a novel competitive fluorescence assay employing identical protein‐conjugated nanoparticles as ligands to reversibly immobilize the corresponding nanogels. Both nanogels exhibited K d <10 pM for their respective target protein and low cross‐reactivity with five reference proteins. This agrees with affinities reported for solid‐phase‐synthesized nanogels prepared using low‐surface‐area glass‐bead supports. This approach simplifies the development and production of plastic antibodies and offers direct access to a practical bioassay.

We report an approach integrating the synthesis of protein‐imprinted nanogels (“plastic antibodies”) with a highly sensitive assay employing templates attached to magnetic carriers. The enzymes trypsin and pepsin were immobilized on amino‐functionalized solgel‐coated magnetic nanoparticles (magNPs). Lightly crosslinked fluorescently doped polyacrylamide nanogels were subsequently produced by high‐dilution polymerization of monomers in the presence of the magNPs. The nanogels were characterised by a novel competitive fluorescence assay employing identical protein‐conjugated nanoparticles as ligands to reversibly immobilize the corresponding nanogels. Both nanogels exhibited Kd<10 pM for their respective target protein and low cross‐reactivity with five reference proteins. This agrees with affinities reported for solid‐phase‐synthesized nanogels prepared using low‐surface‐area glass‐bead supports. This approach simplifies the development and production of plastic antibodies and offers direct access to a practical bioassay.

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.