Amine-Functionalized Silica Coated MIONs for Rapid Removal of Bacterial Pathogens

Bacterial pathogens, owing to their low concentrations, are hard to detect and eliminate by conventional techniques. Magnetic separation techniques have proven to be more efficient and immobilization of bacteria with magnetic nanoparticles has advantages over other techniques, owing to the ease in separation and reuse of separated bacteria. Surface modification of the MIONs with suitable functional group can be considered to combat the toxicity of nanoparticles and also to improve selectivity and efficiency of removal. Synthesis of MIONs by solution combustion method, silica coating for stabilization of the nanoparticles and surface functionalization of the nanoparticles with amine groups has been attempted. XRD, DLS, SEM-EDAX and FTIR techniques were used to characterize the nanoparticles. Removal of bacterial species like Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Salmonella paratyphi by using these functionalized nanoparticles have been explored. The functionalized nanoparticles were found to be effective in the removal of both Gram-positive and Gram-negative bacterial species. Removal of > 90% of bacterial pathogens was achieved in less than 5 min. The results obtained demonstrate the potential of functionalized MION nanoadsorbants as highly efficient materials for removal of pathogens from various liquid samples. (C) 2018 Elsevier Ltd. All rights reserved.