Potential of Functionalized Magnetite (Fe3O4) in Decontamination of Pathogenic Bacteria from Milk

Abstract

Magnetite (Fe3O4) is getting popular due to its super-paramagnetic properties, high biocompatibility and lack of toxicity to humans. Magnetite (Fe3O4) nanoparticles have high surface energy thus these nanoparticles aggregate quickly. This aggregation strongly affects the efficiency of these nanoparticles. So these magnetite nanoparticles are coated with organic or inorganic substance to prevent aggregation. These coatings not only stabilize magnetic nanoparticles but can also be used for further functionalization. The aim of this study was to evaluate the efficiency of functionalized magnetite to remove pathogenic bacteria (E.coli and B.cereus) from milk considering binding capability of magnetite with bacterial cell wall. Magnetite (Fe3O4) was prepared by co-precipitation method and subsequently functionalized with oleic acid (OA) and ethylene diamine (EDA). In present study role of magnetite (Fe3O4) and functionalized magnetite (EDA-Fe3O4, OA-Fe3O4) in removal of pathogenic bacteria (E.coli and B.cereus) from milk was investigated. The morphology of functionalized magnetite was determined by Scanning Electron microscopy (SEM). Their removal efficiency was studied based on time (10, 20 and 30 minutes). Concentration of uncoated magnetite (Fe3O4) and coated magnetite (EDA-Fe3O4, OA-Fe3O4) was fixed at 4mg/50mL. Magnetite was successfully synthesized in range of and#177;3nm. Highest capturing efficiency (74.45%) of oleic acid magnetite (OA-Fe3O4) was observed for Bacillus cereus at 30 minutes. However for Escherichia coli, both ethylene-diamine magnetite (EDA-Fe3O4) and oleic acid magnetite (OA-Fe3O4) showed maximum capturing efficiency (61.65% and 63.91% respectively). It was concluded from the study that magnetite coated with oleic acid and ethylenediamine removed pathogenic bacteria from milk efficiently. However, more research is required to study the effect of these magnetic nanoparticles on nutritional composition of milk.