Temperature-sensitive molecularly imprinted microgels with esterase activity

Temperature-sensitive molecularly imprinted microgels (MIGs) exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate (PAD-His) as the functional macromonomer and p-nitrophenyl phosphate (NPP) as the stable transition state analogue (TSA) as well as Co2+ as the coordination center. The catalytic activity of MIGs was greatly influenced by the amount of the template, and could be modulated by temperature. The hydrolysis kinetics of p-nitrophenyl acetate (NPA) in the presence of MIGs could be described by the Michaelis-Menten equation. The Michaelis-Menten constant and maximum velocity were found to be 2.2 x 10(-5) mol/L and 2.04 x 10(a8) mol/h, respectively. In addition, the MIGs were found to have a high catalytic selectivity to NPA.