Preparation of a PTE simulacrum based on surface molecular imprinting

Firstly, we synthesized N-methacryloyl-histidine monomer and N-methacryloyl-histidine-Cu2+ complex (MAH-Cu2+). Then the molecular imprinting polymers (MIP) has been prepared by surface grafting on uniform polystyrene (PS) core using reversible addition-fragmentation transfer polymerization (RAFT) with MAH-Cu2+ as the functional monomer, methyl paraoxon as the template to simulate phosphotriesterase (PTE). Finally, we have investigated the catalytic hydrolytic activities of MIP and non-imprinting polymers (NIP) to the template methyl paraoxon and the template analogue ethyl paraoxon respectively by UV spectrophotometry. The results showed that the catalytic hydrolytic activity of MIP to the template methyl paraoxon was highest and the value of k is 8.67 × 10−5 mmol L−1 min−1, 3.89-fold higher than MIP to the template analogue ethyl paraoxon, 2.79-fold higher than NIP to the template methyl paraoxon. The KM, rm of MIP are also determined, and KM = 3.95 × 10−4 mol/L, rm = 2.12 μmol/min. The MIP can be reused with only lose 7% of catalytic activity for four cycles.