(584es) Development and Characterization of Highly Mesoporous Magnetic-Silica Aerogel Nanostructures and Their Role in Enzyme Immobilization

Major challenges associated with enzyme catalysts are their high cost and single-use nature. To address these issues, immobilized enzyme systems have gained significant attention. With increasing interest in nanoparticles, magnetic nanoparticles have emerged as promising enzyme supports due to their advantages such as easy recovery, low toxicity, and high stability. However, bare magnetic nanoparticles are prone to oxidation and aggregation, making surface modification essential. Highly porous SiO₂ materials are excellent candidates for surface modification to prevent oxidation and aggregation of magnetic particles. Additionally, they provide a high surface area, tunable pore size, large pore volume, and ease of functionalization.

The development of highly mesoporous magnetic-silica aerogel nanostructures for enzyme immobilization provides several advantages, such as easy recovery from the reaction medium, a high surface area for functionalization and strong enzyme binding, increased enzyme loading capacity, and enhanced stabilization of the enzyme-matrix system.

This study aims to evaluate the enzyme immobilization efficiency of highly mesoporous magnetic-silica aerogel nanostructures prepared with different modifications. Magnetic particles were synthesized via the co-precipitation method. To examine the effects of surface area, pore size, pore volume, and hydrophobicity on enzyme immobilization, silica aerogels were prepared using supercritical CO₂ drying with various modifications. BET analysis confirmed that the magnetic-silica aerogel nanostructures possess a highly mesoporous structure, with surface areas of 500–700 m²/g, pore diameters of 11–23 nm, and pore volumes of 2.5–4.2 cm³/g. Enzyme immobilization was conducted using the physical adsorption method, and immobilization efficiency and activity were evaluated. The support materials were characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-transform Infrared Spectroscopy (FTIR), Nitrogen Adsorption-Desorption Isotherm Analysis (BET and BJH methods), and Vibrating Sample Magnetometry (VSM). These findings suggest that magnetic-silica aerogel nanostructures are promising candidates for industrial enzyme applications, offering enhanced stability, and catalytic efficiency.