Abstract: Molecularly imprinted microgels (MIGs) exhibiting selective esterase activity were prepared by a reverse emulsion method using maleic anhydride esterified dextran-aminopyridine conjugate (Dex-MA-AP) as the functional macromonomer, p-nitrophenyl phosphate (NPP) as the stable transition state analogue (TSA) and Co2+ as the coordination center. The interaction between Dex-MA-AP and NPP was investigated by UV adsorption spectra. The morphology and size of MIGs were observed by scanning electron micrographs (SEM). It was found that the catalytic activity of MIGs was greatly influenced by the amounts of the template and cross-linking agent. The hydrolysis kinetics of p-nitrophenyl acetate (NPA) in the presence of MIGs could be described by the Michaelis-Menten equation. The maximium velocity (Vm) and Michaelis-Menten constant (Km) were found to be 25.1 mmol/h and 0.030 mmol/L, respectively. In addition, the MIGs was found to show high catalytic selectivity to NPA.
Template and target information: p-nitrophenyl phosphate, NPP
Author keywords: enzyme mimics, molecularly imprinting, microgels, catalytic activity, catalytic selectivity