Nanotechnology Research Involving Iron and Iron Oxide Nanoparticles
Any material at the nanoscale is a nanoparticle. Nanoparticles are so small they contain just a few atoms to a few thousand atoms, as opposed to bulk materials that might contain billions of atoms. This difference in size causes nanomaterials to have unique characteristics.
Iron is an element that, in its bulk form, is used in such everyday settings as stair railings and the structural beams in cars or buildings. Iron is also present in water and in the bloodstream, where it helps to transport oxygen.
Iron is one of the materials that can be used to make magnets due to the way electrons orbit each atom. And, as you know, iron rusts when you combine iron and oxygen to form iron oxide. It turns out that nanoparticles of both iron and iron oxide can be quite useful.
Rusty nanoparticles improve magnetic resonance imaging (MRI)
If iron is left in the rain it will rust, and rust is composed of iron oxide, a molecule that contains three atoms of iron and four atoms of oxygen.
Like iron, iron oxide has magnetic properties. Iron has four unpaired electrons, whereas iron oxide has only two unpaired electrons. Because the unpaired electrons make a material magnetic, iron oxide is less magnetic than iron. Iron oxide is therefore called a paramagnetic material. The paramagnetic properties of iron oxide nanoparticles are not changed from the bulk material except that these tiny particles can go where larger particles never could.
For example, in magnetic resonance imaging (MRI), you get a better image if paramagnetic nanoparticles are attached to the object you’re taking an image of. For that reason, researchers are functionalizing iron oxide nanoparticles by coating them with molecules that are attracted to cancer tumors to provide a better MRI image.
Making nanoparticles that have a core made of iron oxide nanocrystals surrounded by nanoporous silica can improve not only the MRI images of tumors but also give researchers control over the release of therapeutic drugs.
Clean up ground water with iron nanoparticles
Iron nanoparticles also retain iron’s magnetic properties. What’s interesting is that, like iron oxide, these magnetic nanoparticles have increased surface area. This allows the iron nanoparticles to be useful in both medical imaging and cleaning up pollutants in groundwater.
Researchers are investigating the use of iron nanoparticles as the next step beyond iron oxide nanoparticles for medical imaging and treatments such as the following:
Targeted drug delivery: Using nanoparticles with an iron core, drug delivery can be guided by a magnetic field to a particular region of a patient’s body.
Improved MRI imaging and treatment: After an MRI image shows that nanoparticles are concentrated at the diseased region, an oscillating magnetic electric field would be used to vibrate the nanoparticles, creating heat to kill the diseased cells.
Treating ground water: Iron nanoparticles are also useful in cleaning up organic pollutants in groundwater because they can donate electrons to more electronegative atoms, such as chlorine atoms, present in many of the molecules that make up organic pollutants.
Donating these electrons can cause the molecules to break up into harmless molecules. Because nanoparticles can remain suspended in groundwater for a long time and are transported throughout the system, they are used to treat large areas of groundwater.