Synthesis and characterisation of molecularly imprinted catalytic microgels for carbonate hydrolysis

Novel molecularly imprinted microgels incorporating arginine and tyrosine side chains as functional monomers have been designed and synthesised with percentages of cross-linker ranging from 70 to 90%. Full chemico-physical characterisation including M_r, coil density and size particle determination concluded that all polymer preparations obtained can be classified as microgels. Molecular imprinting using a phosphate template was used to generate catalytic microgels for the hydrolysis of p-nitrophenyl carbonates. Kinetic characterisation of the catalytic activity of the different preparations indicated that values of critical monomer concentration (C_M) and percentage of cross-linker play an important role in determining the catalytic efficiency of the different preparations. Microgels containing 70% cross-linker were the only ones following the Michaelis-Menten saturation model and kinetic parameters were obtained using 4 mg/ml of M397: V_max = 1.34 × 10⁻⁶ M s⁻¹ (S.E. 1.28 × 10⁻⁷) and K_M = 2.38 × 10⁻³ M (S.E. 3.1 × 10⁻⁴).