α‐Amylase Immobilization on P(HEMA‐co‐PEGMA) Hydrogels: Preparation, Characterization, and Catalytic Investigation

Abstract The aims of this study are to synthesize and characterize poly (2‐hydroxyethyl methacrylate‐co‐poly (ethylene glycol) methacrylate) (P(HEMA‐co‐PEG500MA)) structures containing polyethylene glycol (PEG) side groups and to investigate their possible use in α‐amylase immobilization. For this purpose, P(HEMA‐co‐PEG500MA) copolymer structures are synthesized by using different monomer ratios. P(HEMA‐co‐PEG500MA) copolymer structures are confirmed by Fourier transform infrared spectroscopy (FTIR), and elemental analysis techniques. In addition, thermal, and morphological properties of the copolymers are investigated by thermal gravimetric analysis/differential scanning calorimetry, and scanning electron microscopy (SEM). Afterward, α‐amylase from Aspergillus oryzae is immobilized on synthesized copolymer support by using physical interactions. The success of immobilization is elucidated via FTIR, SEM, and energy dispersive X‐ray spectroscopy (EDX) methods. In addition, the influences of temperature, pH, storage time, and repeated uses on the activity of free and immobilized α‐amylase are investigated. According to the outcomes, the immobilized α‐amylase possesses a better pH and thermal resistance than the free one. Additionally, the immobilized α‐amylase maintains about 53% of its original activity after eight reuses and it exhibits about 50% relative activity after 28 days of storage. In conclusion, the immobilized α‐amylase can be utilized as a potential efficient catalyst to produce maltose from the hydrolysis of starch.