Combination of hydrophobic effect and electrostatic interaction in imprinting for achieving efficient recognition in aqueous media

An acifluorfen-imprinted polymer (P1) was prepared by the combined use of bismethacryloyl-β-cyclodextrin (BMA-β-CD) and 4-vinylpyridine (4-VP) as functional monomers. Compared with the molecularly imprinted polymers (MIPs) using only BMA-β-CD or 4-VP as a functional monomer, P2 and P3, respectively, P1 showed higher binding capacity (Cp) and imprinting factor (IF) for acifluorfen in aqueous media. Scatchard plot analysis revealed that two classes of binding sites were formed in the imprinted polymer P1 with dissociation constants of 0.435 and 0.868 μmol/ml, respectively. The results of competitive binding experiments showed that P1 can separate acifluorfen from its structural analogs. The study indicated that the combination of hydrophobic effect and electrostatic interaction in imprinting process is a feasible approach for achieving molecular recognition in aqueous media.