43 research outputs found
Nanoscale Metallic Iron for Environmental Remediation: Prospects and Limitations
The amendment of the subsurface with nanoscale metallic iron particles
(nano-Fe0) has been discussed in the literature as an efficient in situ
technology for groundwater remediation. However, the introduction of this
technology was controversial and its efficiency has never been univocally
established. This unsatisfying situation has motivated this communication whose
objective was a comprehensive discussion of the intrinsic reactivity of
nano-Fe0 based on the contemporary knowledge on the mechanism of contaminant
removal by Fe0 and a mathematical model. It is showed that due to limitations
of the mass transfer of nano-Fe0 to contaminants, available concepts cannot
explain the success of nano-Fe0 injection for in situ groundwater remediation.
It is recommended to test the possibility of introducing nano-Fe0 to initiate
the formation of roll-fronts which propagation would induce the reductive
transformation of both dissolved and adsorbed contaminants. Within a
roll-front, FeII from nano-Fe0 is the reducing agent for contaminants. FeII is
recycled by biotic or abiotic FeIII reduction. While the roll-front concept
could explain the success of already implemented reaction zones, more research
is needed for a science-based recommendation of nano- Fe0 for subsurface
treatment by roll-front
Optical and MRI multifunctional nanoprobe for targeting gliomas
A multifunctional nanoprobe capable of targeting glioma cells, detectable by both magnetic resonance imaging and fluorescence microscopy, was developed. The nanoprobe was synthesized by coating iron oxide nanoparticles with covalently bound bifunctional poly(ethylene glycol) (PEG) polymer, which were subsequently functionalized with chlorotoxin and the near-infrared fluorescing molecule Cy5.5. Both MR imaging and fluorescence microscopy showed significant preferential uptake of the nanoparticle conjugates by glioma cells. Such a nanoprobe could potentially be used to image resections of glioma brain tumors in real time and to correlate preoperative diagnostic images with intraoperative pathology at cellular-level resolution