By IANS,
Washington : A natural, nontoxic method for biodegrading carbon nanotubes could help diminish environmental and health concerns about using such materials.
A Pittsburgh University research team has found that carbon nanotubes deteriorate when exposed to the natural enzyme horseradish peroxidase (HRP), according to a report co-authored by Alexander Star, assistant professor of chemistry in Pitt’s School of Arts and Sciences.
His co-author is Valerian Kagan, a professor at the department of environmental and occupational health in Pitt’s Graduate School of Public Health. These findings were published recently in Nano Letters.
These results open the door to further development of safe and natural methods – with HRP or other enzymes – of cleaning up carbon nanotube spills in the environment and the industrial or lab setting.
Carbon nanotubes are one-atom thick rolls of graphite 100,000 times smaller than a human hair yet stronger than steel and excellent conductors of electricity and heat, said a Pitt’s release.
They reinforce plastics, ceramics, or concrete; conduct electricity in electronics or energy-conversion devices; and are sensitive chemical sensors, Star said.
He also created an early-detection device for asthma attacks wherein carbon nanotubes detect minute amounts of nitric oxide preceding an attack.
“The many applications of nanotubes have resulted in greater production of them, but their toxicity remains controversial,” Star said.
The team’s work focussed on nanotubes in their raw form as a fine, graphite-like powder, Kagan explained. In this form, nanotubes have caused severe lung inflammation in lab tests.
Although small, nanotubes contain thousands of atoms on their surface that could react with the human body in unknown ways, Kagan said. Both he and Star are associated with a three-year-old Pitt initiative to investigate nanotoxicology.