Dual-functional OPH-immobilized polyamide nanofibrous membrane for effective organophosphorus toxic agents protection

In both civilian and military domains, the increasing use of highly toxic organophosphates (OPs) has created an urgent demand for developing an effective method that could protect the human body from OP poisoning. In this study, a novel dual-functional protecting material with both OP filtration and degradation functions was designed and fabricated. The filtration function was endowed by the electrospinning polyamide 66 (Nylon 66, PA-66) nanofibrous membrane, while the OP degradation function was based on the immobilization of organophosphorus hydrolase (OPH) on membrane through glutaraldehyde (GA) crosslinking. A systematic study of the relationship between the membrane structure, filtration ability and OP degradation activity revealed that PA-66 nanofibrous enzyme with 20 mu m thickness exhibited perfect uniform morphology, and the particle filtration efficiency was over 99%. The nanofibrous enzyme exhibited a specific activity of 41 U/g; the enzyme activity recovery was 53.3%, and the methyl parathion (MP) degradation efficiency was 40%. Moreover, the nanofibrous enzyme expressed excellent organic solvent stability; approximately 70% of its initial activity was retained after incubation in xylene solvent for 24 h at 25 degrees C. The residual activity was 40% after being stored for 30 d at 25 degrees C After 10 repeated uses, the residual activity of the nanofibrous membrane was 37%. This study demonstrated the application potential of dual-functional PA-66 nanofibrous enzyme in biochemical protection, aimed at various military and civilian applications. (C) 2015 Elsevier B.V. All rights reserved.