Duan Xiaonan, Corgié Stéphane C, Aneshansley Daniel J, Wang Peng, Walker Larry P, Giannelis Emmanuel P
Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853 (USA).
Chemphyschem. 2014 Apr 4;15(5):974-80. doi: 10.1002/cphc.201300808. Epub 2014 Feb 20.
We report a new family of hierarchical hybrid catalysts comprised of horseradish peroxidase (HRP)-magnetic nanoparticles for advanced oxidation processes and demonstrate their utility in the removal of phenol from water. The immobilized HRP catalyzes the oxidation of phenols in the presence of H2 O2 , producing free radicals. The phenoxy radicals react with each other in a non-enzymatic process to form polymers, which can be removed by precipitation with salts or condensation. The hybrid peroxidase catalysts exhibit three times higher activity than free HRP and are able to remove three times more phenol from water compared to free HRP under similar conditions. In addition, the hybrid catalysts reduce substrate inhibition and limit inactivation from reaction products, which are common problems with free or conventionally immobilized enzymes. Reusability is improved when the HRP-magnetic nanoparticle hybrids are supported on micron-scale magnetic particles, and can be retained with a specially designed magnetically driven reactor. The performance of the hybrid catalysts makes them attractive for several industrial and environmental applications and their development might pave the way for practical applications by eliminating most of the limitations that have prevented the use of free or conventionally immobilized enzymes.
我们报道了一种由辣根过氧化物酶（HRP）-磁性纳米颗粒组成的新型分级混合催化剂，用于高级氧化过程，并展示了它们在从水中去除苯酚方面的效用。固定化的HRP在H2O2存在下催化苯酚的氧化，产生自由基。苯氧基自由基在非酶过程中相互反应形成聚合物，这些聚合物可以通过盐沉淀或缩合去除。与游离HRP相比，混合过氧化物酶催化剂的活性高出三倍，并且在相似条件下从水中去除苯酚的量是游离HRP的三倍。此外，混合催化剂减少了底物抑制并限制了反应产物的失活，而这是游离或传统固定化酶常见的问题。当HRP-磁性纳米颗粒混合物负载在微米级磁性颗粒上时，其可重复使用性得到改善，并且可以通过专门设计的磁驱动反应器保留下来。混合催化剂的性能使其在多个工业和环境应用中具有吸引力，它们的开发可能通过消除阻碍游离或传统固定化酶使用的大多数限制，为实际应用铺平道路。
