University of Pittsburgh researchers have hit upon a novel way to clean up carbon nanotubes, that promises to cut potential risks to environment and health.
The researchers have found that carbon nanotubes deteriorate when exposed to the natural enzyme horseradish peroxidase (HRP).
They say that these findings pave the way for the development of safe and natural methods-with HRP or other enzymes-of cleaning up carbon nanotube spills in the environment and the industrial or laboratory setting.
"The many applications of nanotubes have resulted in greater production of them, but 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. We have demonstrated a nontoxic approach to successfully degrade carbon nanotubes in environmentally relevant conditions," says Alexander Star, an assistant professor of chemistry in Pitt's School of Arts and Sciences.
Valerian Kagan, a professor and vice chair of the Department of Environmental and Occupational Health in Pitt's Graduate School of Public Health, revealed that the study focused on nanotubes in their raw form as a fine, graphite-like powder.
Nanotubes in this form have been found to cause severe lung inflammation in lab tests.
Kagan said that despite being small, nanotubes contain thousands of atoms on their surface that could react with the human body in unknown ways.
"Nanomaterials aren't completely understood. Industries use nanotubes because they're unique-they are strong, they can be used as semiconductors. But do these features present unknown health risks? The field of nanotoxicology is developing to find out. 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," Kagan said.
The authors of the study revealed that the research team broke down the nanotubes by exposing them to a solution of HRP and a low concentration of hydrogen peroxide at 4 degrees Celcius (39 degrees Fahrenheit) for 12 weeks.
They believe that this approach may one day be as easy to administer as chemical clean-ups in today's labs.
A report on their study has been published in the journal Nano Letters.