Core/shell molecular imprinting microparticles prepared using RAFT technology for degradation of paraoxon

Abstract

We have developed a uniform core-shell structured surface hydrogel imprinted molecular imprinting polymer (MIP). This was achieved by surface grafting on a disulfide ester modified polystyrene core, using reversible addition-fragmentation transfer polymerization (RAFT) with N-methacryloyl-histidine-Cu2+ complex (MAHCu 2+) as the functional monomer and methyl paraoxon as the template to simulate phosphotriesterase (PTE). Subsequently, we investigated the catalytic (hydrolytic) activities of MIP to the template methyl paraoxon and the template analogue ethyl paraoxon. The results showed that the catalytic (hydrolytic) activity of MIP to the template methyl paraoxon was the highest, and the value of k was 8.67×10−5 mM·L−1·min−1, which was 3.89-fold higher than MIP to ethyl paraoxon and 2.79-fold higher than the non-imprinting polymer (NIP) to methyl paraoxon. The K m and r m of MIP were also determined: the K m was 3.95×10−4 M and the r m 2.12 μM/min. The MIP can be reused with only lose 7% of catalytic activity for four cycles.