Keen Eye For The Nano Guys

By Roland Piquepaille

The SuperSTEM microscope at Daresbury Laboratory in Cheshire, England, is so sensitive that it requires a special building capable of protecting it from the vibrations caused by raindrops. Its resolution is so sharp that researchers can count atoms on its images.

Here is a picture of the SuperSTEM microscope (Credit: Daresbury Laboratory).

[Please note that STEM stands for "scanning transmission electron microscope."]

Other images of this microscope are available from this page.

The new microscope officially opened for business last month, and it has already produced pictures that show metal particles in a diseased liver. Scientists and pathologists are eager to study the wet/dry interface, where particles meet biological systems, in this kind of detail.

Here is a SuperSTEM photo of a ferritin particle. The particle is 3 nanometers across and comes from a human liver (Credit: Dr. Uwe Falke, Daresbury Laboratory.

The article then looks at the potential dangers created by nanoparticles.

Nanoparticles -- particles measured in billionths of a meter -- have existed since the dawn of time. Fires lit by the first humans threw up nanometer-sized particles, as do automobiles today. Even making toast can create them, and large-scale studies indicate that between 3 and 5 percent of deaths could be attributed to these naturally occurring particles.

But the risk is now greater with the advent of artificial nanoparticles created in laboratories. Like any small particle, this material could be more chemically reactive, and with industrial production of nano-sized materials there is increased risk of more particles entering the atmosphere.

This is to identify these dangers that this microscope is needed because its images are dramatically better than the ones obtained with other electron microscopes.

"It has a resolution of one angstrom, or one-tenth of a nanometer," said Dr. Andrew Bleloch, technical director of the SuperSTEM. "You can count the atoms now, whereas before they were just this sort of blur."

Electron microscope images are marred by positive spherical aberration, which damages image definition. SuperSTEM eliminates that aberration. "You could describe the SuperSTEM as an electron microscope with spectacles," said Ryk Brydson from Leeds University.

For other possible dangers created by nanoparticles, please read this recent post, "Can Nanoparticles Enter Our Brains?"

Source: Daithí Ó hAnluain, Wired News, January 13, 2004