Direct amine-functionalisation of γ-Fe₂O₃nanoparticles

Abstract

A novel and simple preparation of amine-modified γ-Fe2O3 nanoparticles is described. The presence of amine groups on the surface, instead of hydroxyl groups, will allow conjugation of biologically active molecules to the iron oxide nanoparticles without the need for a size increasing silica shell. Furthermore, the outer amine-layer increases the temperature of the γ-Fe2O3 to α-Fe2O3 structural transition in a similar way to previously reported cationic substitutions. This may suggest the formation of an oxide-nitride outer layer. Re-dispersion of the amine-modified γ-Fe2O3 nanoparticles led to the preparation of stable ferrofluids.

Optimization of Lipase Immobilization on Maghemite and Its Physico-Chemical Properties

“…An exothermic peak was observed at 456.3°C indicating the transition of maghemite to hematite. This is similar to the result reported by (Rocher, Manerova, Kinnear, Evans, & Francesconi, 2014), who recorded the transition temperature of maghemite to hematite below 500°C. Perhaps, this is due to the smaller size of the maghemite synthesized (Darezereshki, 2011).…”

Enhanced Thermal Protection of Iron Oxide Nanoparticle by Insulating Nanoporous Char Layer: Effect of Core Size and Char Layer Properties

“…To overcome these problems, particles are functionalized with a layer of surfactant, polymer, or noble metal layer. 16 Again, there are issues concerning compatibility of surface active moieties with carrier fluids. Among various coatings, magnetite capped with carbon material by carbonization of polymer has gained significant interest for applications as electrode for lithium ion batteries, 17 fuel cells, 18 hydrogenation of nitroarenes to amines, 19 degradation of dye, 20 removal of ions, 21 and organic pollutants.…”

“…Bare Fe 3 O 4 nanoparticles are prone to oxidation and aggregation. To overcome these problems, particles are functionalized with a layer of surfactant, polymer, or noble metal layer . Again, there are issues concerning compatibility of surface active moieties with carrier fluids.…”

P(EO-co-LLA) functionalized Fe3O4@mSiO2 nanocomposites for thermo/pH responsive drug controlled release and hyperthermia

“…[17][18][19] Currently, nanoparticles, organic molecules and supramolecular nanovalves have been employed as "gatekeepers" for MSNs, and the controlled release process can be regulated by many special stimuli, such as thermal/electrostatics/magnetic actuation, light, photoirradiation, pH and enzymes. [33][34][35] Moreover, magnetic nanoparticles can produce localized hyperthermia by hysteresis heating upon exposure to an alternating magnetic field (AMF). 27 In our previous study, the Konjac oligosaccharide (KOGC) was adopted as the "gatekeeper".…”

“…32 Ultra-small γ-Fe 2 O 3 nanoparticles have also been described as the potential specific positive contrast agents for magnetic resonance molecular imaging. [33][34][35] Moreover, magnetic nanoparticles can produce localized hyperthermia by hysteresis heating upon exposure to an alternating magnetic field (AMF). 36 When the temperature is raised to 42-45 °C, tumor/cancer cells are damaged or killed due to overheating, while most of the normal cells far away from the magnetic nanoparticles survive.…”