Physical Properties of Magnetite Nanoparticles Covered by 11-Mercaptoundecanoic Acid

We have investigated the magnetic behavior of magnetite nanoparticles covered by the 11-mercaptoundecanoic acid around magnetite core prepared by a standard co-precipitation method. The particles show superparamagnetic behavior at room temperature, with transition to a blocked state at blocking temperature 91 K estimated from zero field cooled and field cooled at 500 Oe experiment. The hysteresis loop measured at 293 K showed magnetization 32.8 emu/g at 50 kOe without any coercivity. The mean particle size (7.1 nm) was determined by fitting a magnetization curve obtained at 295 K assuming a log-normal size distribution

Physical Properties of Magnetite Nanoparticles Covered by 11-Mercaptoundecanoic Acid

We have investigated the magnetic behavior of magnetite nanoparticles covered by the 11-mercaptoundecanoic acid around magnetite core prepared by a standard co-precipitation method. The particles show superparamagnetic behavior at room temperature, with transition to a blocked state at blocking temperature 91 K estimated from zero eld cooled and eld cooled at 500 Oe experiment. The hysteresis loop measured at 293 K showed magnetization 32.8 emu/g at 50 kOe without any coercivity. The mean particle size (7.1 nm) was determined by tting a magnetization curve obtained at 295 K assuming a lognormal size distribution

Anti-amyloidogenic activity of glutathione-covered gold nanoparticles

This study is an investigation of the effect of biocompatible glutathione-covered gold nanoparticles (AuSG_7) with an average size of 3 nm on the amyloid fibrils of hen egg-white lysozyme. The anti-amyloid activity of AuSG_7 nanoparticles on this protein was monitored with thioflavin T assay, atomic force microscopy and transmission electron microscopy. The study found that AuSG_7 nanoparticles in vitro depolymerize the amyloid aggregates and inhibit lysozyme aggregate formation. The ability to inhibit amyloid formation and promote amyloid disassembly has concentration-dependent characteristics: the concentration of nanoparticles at which inhibition is half maximal (IC50) was found to be 6.19 mu g/mL, and the concentration at which depolymerization is half maximal (DC50) was found to be 826 mu g/ml. (C) 2012 Elsevier B.V. All rights reserved