Abstract
The role of support and immobilization protocol is crucial in enzyme immobilization to realize their industrial applications. The use of nanogels as support and linkage of enzyme to the support by covalent linkage are two areas of interest investigated in the present work where urease was used as the candidate enzyme. Urease is an important enzyme that catalyses the breakdown of urea. In the present case a new series of tri-propylene glycol dimethacrylate (TPGDA) crosslinked (-cl-) and poly(Acrylic acid)[poly(AAc)]-based functional nanogels were prepared and used for covalent immobilization of urease. The poly(AAc)-nanogel was functionalized to poly(acrylazide) and poly(acryloyl isocyanate) forms. All the three functional forms of nanogel were used as supports for the covalent immobilization of urease. The activity assay of the free and immobilized urease was carried out by Weatherburn protocol. The specific activity, reusability and storability of the immobilized urease were determined to assess effect of immobilization. The free and immobilized nanogels were characterized by X-Ray diffraction (XRD), Fourier Transform Infra Red (FTIR) spectroscopy, scanning electron microscopy (SEM) and particle size analysis to get evidence of the network formation, functionalization and urease immobilization. The immobilized-urease exhibited higher activity than the free urease. Also, reusability up to nine cycles was exhibited by the immobilized urease.
Keywords: Activity assay, Covalent Immobilization, Nanogel, Support, Reusability, Urease.
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