Scientists kill gray goo with horseradish

Fear not the gray goo: researchers have created a non-toxic substance that can break it down. And the main ingredient is horseradish.

Developed by a team at the University of Pittsburgh, the technique anticipates haz-mat scenarios that have become a staple of science fiction—think tiny robots on a crazed self-replication bender—whose more mundane reality could still cause problems as nanotechnology leaves the lab.

Following publication a report in the Nano Letters journal, co-author Alexander Star said that nanotubes are under production but that their toxicity remains controversial.

"Accidental spills of nanotubes are inevitable during their production, and the massive use of nanotube-based materials could lead to increased environmental pollution," Star said in a press release.

The report's abstract describes how the Pitt team degraded single-walled carbon nanotubes using horseradish peroxidase and hydrogen peroxide. They worked on the nanotubes in their "raw form"—a fine power—already known to cause severe lung inflammation.

“Nanomaterials aren't completely understood," said Valerian Kagan, a professor and vice chair of the Department of Environmental and Occupational Health in Pitt's Graduate School of Public Health, in a press release. “Studies have shown that they can be dangerous. We wanted to develop a method for safely neutralizing these very small materials should they contaminate the natural or working environment.”

The team anticipates their method could be used "as easily as chemical cleanups in today's labs."

Press release [University of Pittsburgh]

Abstract of Biodegradation of Single-Walled Carbon Nanotubes through Enzymatic Catalysis [Nano Letters]