Design of enzyme-immobilized polymer brush-grafted magnetic nanoparticles for efficient nematicidal activity

Parasitic nematodes not only cause deadly diseases in plants and animals but also adversely affect agricultural industry and global health, particularly in developing countries. In this study, we planned to combine the concept of enzyme immobilization with nanotechnology to develop magnetic nanoparticles (MNPs) with efficient nematicidal activity in water. A novel nematicidal platform was developed by immobilizing protease (from Streptomyces griseus) on the surface of polymer brush-grafted magnetic nanoparticles (MNPs-PGMA-Pro). For comparison, a monolayer-based nematicidal platform was also developed by functionalizing protease on the surface of glutaraldehyde-functionalized MNPs (MNPs-GA-Pro). MNPs-PGMA-Pro particles show enhanced enzyme activity and stability over a wide range of temperature and pH, as compared to MNPs-GA-Pro. Polymer brush- and monolayer-based protease-functionalized MNPs exhibit superior enzyme activity when compared to the free enzyme. When tested for nematicidal activity against parasitic nematodes (Haemonchus contortus), the polymer brush- based platform retained higher activity over 7 cycles of magnetic separation. The reported platforms can be prospectively employed for water treatment, whereas their reusability over many remediation cycles due to facile magnetic separation promises a substantially reduced treatment cost.