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

An acifluorfen-imprinted polymer (Pi) was prepared by the combined use of bismethacryloyl-beta-cyclodextrin (BMA-P-CD) and 4-vinylpyridine (4-VP) as functional monomers. Compared with the molecularly imprinted polymers (MIPs) using only BMA-beta-CD or 4-VP as a functional monomer, P-2 and P-3, respectively, P-1 showed higher binding capacity (C-p) 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 P-1 with dissociation constants of 0.435 and 0.868 mu mol/ml, respectively. The results of competitive binding experiments showed that P-1 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. (C) 2009 Elsevier Ltd. All rights reserved.