Mass-Producing Tunable Magnetic Nanoparticles

May 21, 2008

Taking a cue from the semiconductor industry, a team of investigators at Stanford University has developed a method of producing unlimited quantities of highly magnetic nanoparticles suitable for use as magnetic resonance tumor imaging agents.

Equally important, this method can be easily tailored to produce nanoparticles with a wide range of well-defined magnetic properties. Tunability creates the opportunity to use these nanoparticles in multiplexed biosensing applications akin to those now being developed using tunable quantum dots of multiple colors.

Shan Wang, Ph.D., a member of the Center for Cancer Nanotechnology Excellence Focused on Therapy Response, one of eight Centers of Cancer Nanotechnology Excellence (CCNEs) funded by the NCI, led a research team that has been exploring methods of creating large, uniform batches of magnetic nanoparticles. Their current work, reported in the journal Advanced Materials, describes a technique for fabricating magnetic nanoparticles that involves forming two magnetic layers sandwiched around a layer of nonmagnetic material.

To create these sandwich particles, the investigators use a technique known as nanoimprint lithography to create cobalt-iron nanodisks. As a nonmagnetic spacer, the researchers used nanometer-thick layers of ruthenium. By varying the thickness of the ruthenium spacer layer, the investigators found they could alter the magnetic properties of the resulting nanodisks in a predictable manner. The disks are coated with a thin layer of tantalum to stabilize them.

In addition to producing nanoparticles with tunable magnetic properties, the researchers showed that they could use nanoimprint lithography to add additional layers of materials that afforded the resulting disks with other useful properties. For example, the investigators added a layer of gold onto the tantalum surfaces, creating magnetic nanoparticles that could also be detected using surface plasmon resonance imaging, a sensitive optical imaging technique.

This work, which was supported by the NCI’s Alliance for Nanotechnology in Cancer, is detailed in the paper “High-Moment Antiferromagnetic Nanoparticles with Tunable Magnetic Properties.” There is no abstract available for this paper, but a citation is available at the journal’s Web site.

Source: National Cancer Institute

Explore further: Mirror-image forms of corannulene molecules could lead to exciting new possibilities in nanotechnology

add to favorites email to friend print save as pdf

Related Stories

The science that stumped Einstein

Jul 01, 2014

In 1908, the physics world woke up to a puzzle whose layers have continued to stump the greatest scientists of the century ever since. That year, Dutch physicist Kamerlingh Onnes cooled mercury down to -450° ...

Recommended for you

Tiny graphene drum could form future quantum memory

Aug 28, 2014

Scientists from TU Delft's Kavli Institute of Nanoscience have demonstrated that they can detect extremely small changes in position and forces on very small drums of graphene. Graphene drums have great potential ...

Graphene reinvents the future

Aug 27, 2014

For many scientists, the discovery of one-atom-thick sheets of graphene is hugely significant, something with the potential to affect just about every aspect of human activity and endeavour.

User comments : 0