Silica Sol-Gel Entrapment of the Enzyme Chloroperoxidase

Abstract

The enzyme chloroperoxidase (CPO) was immobilized in silica sol-gel beads prepared from tetramethoxysilane. The average pore diameter of the silica host structure (∼3 nm) was smaller than the globular CPO diameter (∼6 nm) and the enzyme remained entrapped after sol-gel maturation. The catalytic performance of the entrapped enzyme was assessed via the pyrogallol peroxidation reaction. Sol-gel beads loaded with 4 g CPO per mL sol solution reached 9-12% relative activity compared to free CPO in solution. Enzyme kinetic analysis revealed a decrease in cat but no changes in or . Product release or enzyme damage might thus limit catalytic performance. Yet circular dichroism and visible absorption spectra of transparent CPO sol-gel sheets did not indicate enzyme damage. Activity decline due to methanol exposure was shown to be reversible in solution. To improve catalytic performance the sol-gel protocol was modified. The incorporation of 5, 20, or 40% methyltrimethoxysilane resulted in more brittle sol-gel beads but the catalytic performance increased to 14% relative to free CPO in solution. The use of more acidic casting buffers (pH 4.5 or 5.5 instead of 6.5) resulted in a more porous silica host reaching up to 18% relative activity.

Functionalizing silica sol–gel with entrapped plant virus-based immunosorbent nanoparticles

“…The prepared solution was aliquoted as 40 µL droplets onto parafilm at room temperature for gel bead formation. The droplet size, comparable to previous silica sol–gel droplet studies [ 25 ], was selected as a balance of surface area-to-volume ratio for diffusion purposes with the minimum volumes required for analysis and manual manipulation. A smaller droplet size (2 µL) was aliquoted for fluorescent microscope imaging to accommodate the full cross-sectional area within the restricted microscope field of view.…”

Synthesis and Characterization of Silica and Silica Cellulose from Natural Materials as Matrix for Various Sensor Applications: A Mini Review

“…Additionally, combining silica with other natural materials, such as cellulose, can lead to the development of hybrid materials with better properties. Silica, also known as silicon dioxide (SiO2), is a chemical compound consisting of silanol and siloxane groups [24]. In the context of sensor matrices, silica can be used as a base material or matrix which allows the integration of reagents and analytes in the development of various types of sensors [25].…”

Pengaruh Pemerangkapan Enzim Alkalin Fosfatase ke dalam Silika dari Abu Sekam Padi terhadap Aktivitas Enzimatiknya

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