超细SiO_2颗粒的制备及其对α-淀粉酶的吸附固定化

Preparation of Ultrafine Silica Particles and Their Application in α-Amylase Immobilization

采用Triton X-100反胶团体系法和Stber法分别制备粒径为50 nm及1μm的SiO2颗粒,用二氯二甲基硅烷(DDS)对其进行表面疏水性修饰,用于α-淀粉酶的固定化.结果表明,经DDS修饰的SiO2颗粒对α-淀粉酶的吸附能力明显提高,且有效提高了吸附稳定性,经6次洗涤后酶活仅损失30%;1μm SiO2颗粒比50 nm SiO2颗粒对α-淀粉酶的吸附量大,SiO2颗粒载体固定的α-淀粉酶的活性为50 nm SiO2>1μm SiO2>50 nm修饰后SiO2>1μm修饰后SiO2.

50 nm and 1 μm SiO2 particles were prepared using TritonX-100 reverse micellar system and Stober method, respectively. The particles were then modified with dichlorodimethylsilane to render their surfaces hydrophobic for immobilization of u-amylase. The results showed that compared with unmodified SiO2 particles, the adsorption capacity of a-amylase on modified SiO2 particles was obviously improved, and the stability of immobilized a-amylase was also effectively increased, as evidenced by only 30% loss of activity after 6 times washing. The adsorption capacity of a-amylase on 1 μm SiO2 particles was higher than that on 50 nm SiO2 particles, while the activity of immobilized a-amylase on the different carriers was ranked in the order of 50 nm SiO2 〉 1 μm SiO2 〉 modified 50 nm SiO2 〉 modified 1 μm SiO2.