2 research outputs found
Magnetic Silver Hybrid Nanoparticles for Surface-Enhanced Resonance Raman Spectroscopic Detection and Decontamination of Small Toxic Molecules
Magnetic hybrid assemblies of Ag and Fe<sub>3</sub>O<sub>4</sub> nanoparticles with biocompatibly immobilized myoglobin (Mb) were designed to detect and capture toxic targets (NO<sub>2</sub><sup>–</sup>, CN<sup>–</sup>, and H<sub>2</sub>O<sub>2</sub>). Mb was covalently attached to chitosan-coated magnetic silver hybrid nanoparticles (M-Ag-C) <i>via</i> glutaraldehyde that serves as a linker for the amine groups of Mb and chitosan. As verified by surface-enhanced resonance Raman (SERR) spectroscopy, this immobilization strategy preserves the native structure of the bound Mb as well as the binding affinity for small molecules. On the basis of characteristic spectral markers, binding of NO<sub>2</sub><sup>–</sup>, CN<sup>–</sup>, and H<sub>2</sub>O<sub>2</sub> could be monitored and quantified, demonstrating the high sensitivity of this approach with detection limits of 1 nM for nitrite, 0.2 μM for cyanide, and 10 nM for H<sub>2</sub>O<sub>2</sub>. Owing to the magnetic properties, these particles were collected by an external magnet to achieve an efficient decontamination of the solutions as demonstrated by SERR spectroscopy. Thus, the present approach combines the highly sensitive analytical potential of SERR spectroscopy with an easy approach for decontamination of aqueous solutions with potential applications in food and in environmental and medical safety control
Properties of New Magnetic Surfactants
This Article describes the synthesis
and detailed characterization
of a new set of magnetic surfactants containing lanthanide metal counterions.
SQUID magnetometry has been used to elucidate the magnetic phase behavior,
and small-angle neutron scattering (SANS) provides evidence of micellar
aggregation in aqueous media. This study also reveals that for cationic
surfactants in aqueous systems there appears to be no significant
increase in magnetic susceptibility after micellization