纳米氧化硅固定辣根过氧化物酶处理苯酚废水

Horseradish peroxidase encapsulated on nanosilica for phenol removal

在温和条件下（室温、中性pH）,以聚乙烯亚胺（PEI）为诱导剂诱导纳米氧化硅粒子的形成,同时固定化辣根过氧化物酶（HRP）。FT-IR表征结果证实载体为氧化硅,且HRP被成功固定于载体中。SEM分析显示,生成的含HRP的氧化硅粒子为球形,大小在200~500 nm之间。体系溶剂类型影响诱导剂PEI和HRP分子间或分子内的静电作用,从而影响固定化效果。结果表明选用磷酸缓冲液作为体系溶剂固定化效果最佳,包埋率达65.3%。相对于初始加入的游离HRP,固定化HRP保持了70.8%的活性,且稳定性得到显著提高。固定化HRP用于处理含酚废水,苯酚去除率最高可达到73.1%。固定化酶重复使用5次,仍保留初始催化活性的51.7%。

Encapsulation is demonstrated to be an effective method for enzyme immobilization.Compared to traditional methods,the biomimetic approach at mild conditions has garnered much interest.For the removing phenol in waste-water,silica formed by polyethyleneimine-inducer was used to immobilize horseradish peroxidase（HRP）at room temperature and neutral pH in this paper.The results of SEM show that immobilized HRP particles are near-spheres from 200 to 500 nm.FT-IR spectra indicate that HRP is successfully encapsulated within the silica matrix.The immobilized HRP can be of higher thermal,pH and storage stability.The electrostatic interaction between polyethyleneimine and HRP i.e.immobilization ratio of HRP is affected by type of solvent used.If phosphate buffer is employed as system solvent,immobilization ratio of HRP is 65.3% and activity ratio is 70.8%.The silica-encapsulated HRP obtained was used for removal of phenol,and maximum removal could reach 73.1%.After 5 repeated cycles,51.7% of initial activity is still retained.