Iron oxides are abundant organic compounds that can also be easily made in the laboratory. There are 16 types of iron oxides, including oxides, hydroxides, and oxide-hydroxides.
These minerals are the product of aqueous reactions at varying redox and pH levels. They share the basic composition of Fe, O, and/or OH but differ in the valency of iron and overall crystal structure. Important iron oxides include goethite, akaganeite, lepidocrocite, magnetite, and hematite.
Iron oxide (IO) nanoparticles, which have diameters between 1 and 100 nanometers, are made up of maghemite (γ-Fe2O3) and/or magnetite (Fe3O4) particles. They are used in the administration of drugs, biosensing, and magnetic data storage, among other uses.
The surface area to volume ratio significantly rises in nanoparticles (NPs). This gives NPs superior dispersibility in solutions and a significantly larger binding capacity.
Magnetic nanoparticles (NPs) can be magnetized by an external magnetic source and exhibit superparamagnetism, or zero magnetization, in the absence of an external magnetic field. NPs range in size from 2 to 20 nm. This characteristic gives magnetic nanoparticles in solutions extra stability.
Due to their superparamagnetic qualities, biocompatibility, and lack of toxicity, IO nanoparticles have garnered great attention for their prospective use in biomedicine. In terms of size tunability, monodispersity, and crystalline structure, recent advancements in the production of IO nanoparticles through the thermal breakdown of iron carboxylate salts have significantly improved the quality of conventional IO nanoparticles.
Hydrophobic, organic ligand-coated IO nanoparticles have been effectively transformed into water-soluble, bio-accessible IO nanoparticles using the patented monolayer polymer coating technique. These water-soluble IO nanoparticles are highly stable under extreme temperatures and pH ranges, which permits NP conjugation with other biomolecules.
The US Food and Drug Administration has certified polysaccharides (like dextran) and lipid molecules as additional biocompatible coatings for in vivo studies. As a result, nanoparticles made solely of these materials are now available.
The development of IO nanoparticle-based applications is made possible by improvements in the quality of both organic and water-soluble IO nanoparticles. A few examples of these applications include:
- Therapeutic agents for hyperthermia-based cancer treatments
- Magnetic sensing probes for in-vitro diagnostics (IVD)
- Nanoadjuvant for vaccine and antibody production
- Contrast agents for Magnetic Resonance Imaging (MRI)
- Drug carriers for target-specific drug delivery
- Gene carriers for gene therapy
Materials
Source: Merck
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Iron oxide (II,III), nanoparticles 15 nm avg. part. size (TEM), streptavidin functionalized, 1 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 15 nm avg. part. size (TEM), PEG functionalized, 1 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 25 nm avg. part. size (TEM), 5 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 15 nm avg. part. size (TEM), 5 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 30 nm avg. part. size (TEM), 5 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 25 nm avg. part. size (TEM), 5 mg/mL in toluene |
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Iron oxide (II,III), nanoparticles 5 nm avg. part. size (TEM), 5 mg/mL in chloroform |
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Iron oxide (II,III), nanoparticles 10 nm avg. part. size (TEM), 5 mg/mL in chloroform |
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Iron oxide (II,III), nanoparticles 20 nm avg. part. size (TEM), 5 mg/mL in chloroform |
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Iron oxide (II,III), nanoparticles 10 nm avg. part. size (TEM), streptavidin functionalized, 1 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 30 nm avg. part. size (TEM), streptavidin functionalized, 1 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 15 nm avg. part. size (TEM), carboxylic acid functionalized, 5 mg/mL in H2O |
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Iron oxide (II,III), nanoparticles 25 nm, NHS ester functionalized |
Usually, these magnetic nanoparticles are employed as contrast agents or in imaging. The surface functionality allows for different ligation or further functionalization.