In this work, magnetic Fe₂O₃/Fe₃O₄ nanocomposites were prepared via a novel rapid combustion process. The silica was precipitated on the surface of Fe₂O₃/Fe₃O₄ nanocomposites. The silica-coated magnetic nanocomposites were cross-linked with glutaraldehyde, on which cellulase was covalently immobilized. The morphology, composition, and property of the prepared nanomaterials were characterized by the scanning electron microscopy (SEM), the energy dispersive spectrometry (EDS), the X-ray diffraction (XRD), the vibrating sample magnetometer (VSM), and the Fourier transform infrared (FTIR) spectroscopy. The immobilization conditions were optimized by varying operating parameters and determined to be 0.05 mL of 0.5% cellulase solution for 2 h. The catalytic stabilities of the immobilized cellulase were evaluated. The results showed that the immobilized cellulases performed higher apparent activity at pH 4.5 and exhibited good thermal stability compared with their free counterparts. The Michaelis-Menten equation showed that K_m and V_max of free cellulase were 3.46 mol·L⁻¹ and 0.53 mol·min⁻¹, respectively. The immobilized cellulase had higher K_m and V_max (18.99 mol·L⁻¹ and 0.59 mol·min⁻¹). The retained activity of the immobilized cellulase maintained over 71% of the initial activity after being used for five cycles.

在这项工作中，通过新颖的快速燃烧过程制备了磁性Fe ₂ O ₃ / Fe ₃ O ₄纳米复合材料。二氧化硅沉淀在Fe ₂ O ₃ / Fe ₃ O ₄的表面上纳米复合材料。二氧化硅涂覆的磁性纳米复合材料与戊二醛交联，其上共价固定了纤维素酶。制备的纳米材料的形貌，组成和性能通过扫描电子显微镜（SEM），能量色散谱（EDS），X射线衍射（XRD），振动样品磁力计（VSM）和傅里叶表征。变换红外（FTIR）光谱。通过改变操作参数优化固定条件，并将其确定为0.05 mL的0.5％纤维素酶溶液2小时。评价了固定化纤维素酶的催化稳定性。结果表明，与游离的纤维素酶相比，固定的纤维素酶在pH 4.5下表现出更高的表观活性，并表现出良好的热稳定性。游离纤维素酶的K _m和V _max分别为3.46mol·L ^-1和0.53 mol·min ^-1。固定化的纤维素酶具有较高的K _m和V _max（18.99mol·L ^-1和0.59 mol·min ^-1）。在使用了五个循环后，固定化纤维素酶的保留活性保持了初始活性的71％以上。