Fe3O4@MoS2@PEI-facilitated enzyme tethering for efficient removal of persistent organic pollutants in water

A kind of core-shell material with regular shape and size, and uniform composition, is prepared in aqueous phase and used for laccase immobilization. Magnetic Fe3O4 nanoparticle is coated with MoS2 by self-assembly, and the Fe3O4@MoS2 is further coated by polyethyleneimine, which acts as a spacer arm and is beneficial to enzyme immobilization. The nanocarrier affords the high loading capability of 120 mg/g and satisfied activity recovery of 90% for laccase. The immobilized laccase is stable in a wider range of pH (3-10), temperature (20-70 degrees C) and storage time (1-14 days), as well as having the recyclability (1-10 cycles). The carcinogenic persistent organic pollutants (malachite green, bisphenol A, bisphenol F) in the water are degraded by the immobilized laccase with a higher efficiency (82.7%, 87.6%, 70.6%) than free laccase (14.4%, 85.0%, 48.0%), respectively. It is prospected that the constructed material is qualified as green nanoreactor for biological macromolecules immobilization.