Synthesis, Characterization and Kinetics of Catalytically Active Molecularly Imprinted Polymers for the Selective Recognition of 4-Aminophenol

In the present work a selective molecularly imprinted polymer (MIP) for 4-aminophenol (4-APh) was synthesized by the bulk polymerization technique. Polymerization was carried out in a glass tube containing 4-APh, Fe(III) protoporphyrin(IX) (hemin, Fe(III) PPIX), methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA) and 2,2'-azo-bis-iso-butyronitrile (AIBN). The polymer block was ground and sieved (106 mu m) and the 4-APh was removed from the polymer particles by leaching with a methanol/acetic acid (4: 1, v/v) solution, which leaves a cavity in the polymer particles. Hemin was used as a synthetic material to mimic the active center of peroxidase creating a catalytically active molecularly imprinted polymer. The polymers were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and particle size analysis. The enzymatic performance of the imprinted polymer was evaluated based on kinetic parameters including Vmax and the Michaelis-Menten constant obtained from Lineweaver-Burk plots.