壳聚糖修饰纳米纤维膜表面对氧化还原酶行为的影响

采用静电纺丝法制备了丙烯腈/丙烯酸共聚物(PANCAA)纳米纤维膜, 研究了纺丝液浓度对纤维形态的影响, 以扫描电子显微镜观察纤维形貌, 遴选得到最佳纺丝条件. 以1-乙基-3-(N,N-二甲基氨基丙基)碳二亚胺/N-羟基丁二酰亚胺(EDC/NHS)为偶联剂, 在纤维膜表面引入壳聚糖修饰层, 采用衰减全反射傅里叶变换红外光谱(ATR/FTTIR)、水接触角和称重法考察了修饰前后膜的变化. 通过戊二醛将过氧化氢酶固定到壳聚糖修饰的PANCAA纳米纤维膜上, 研究了壳聚糖及戊二醛浓度对固定化过氧化氢酶的影响, 结果表明, 在壳聚糖浓度为25 mg/mL及戊二醛质量分数为5%条件下, 壳聚糖修饰膜的固定化酶活性比空白膜提高了41.7%, 稳定性也得到了不同程度的提高.

Effect of Chitosan Modification on the Behavior of the Immobilized Redox Enzyme on Nanofibrous Membranes

Poly(acrylonitrile-co-acrylic acid)(PANCAA) nanofibrous membranes were fabricated by electrospinning process. The electrospinning of PANCAA was optimized and the nanofibrous membranes were characterized using field emission scanning electron microscopy(FESEM). Then, chitosan was tethered on the surfaces of the PANCAA nanofibrous membranes in the presence of EDC/NHS. The chemical changes of the membrane surface were characterized by attenuated total reflectance/Fourier transform infrared spectroscopy(ATR/FTIR) and water contact angle measurement. Catalase was immobilized onto the modified nanofibrous membranes using glutaraldehyde(GA) as coupling agent. The enzyme activity and stability were compared with those of the nascent nanofibrous membrane. The max activity was (1011.6±2.1) U/mg under 25 mg/mL chitosan and 2.5% glutaraldehyde for immobilized enzyme. It was found that the activity retention of the immobilized catalase was enhanced by 41.7% and the stability was also enhanced.