SPECIAL FEATURE: EMERGING TECHNOLOGIES
A sensor reacts to minute amounts of nitric oxide, a gas prevalent in the breath of asthmatics.
A recently developed nanotube sensor is reactive to minute amounts of nitric oxide, a gas prevalent in the breath of asthmatics, according to University of Pittsburgh (Pittsburgh, PA) professors who developed the sensor. If fitted in a handheld device, the tiny component could allow users to remove the element of surprise from asthma attacks. In addition to detecting attacks early on, a device incorporating the sensor could provide a portable method for patients and their doctors to regularly monitor their symptoms and tailor treatment accordingly.
The sensor consists of a carbon nanotube, a sheet of graphite 100,000 times smaller than a human hair, and a coating made of a polyethylene imine polymer. Still in the early stages of development, the sensor could eventually offer unprecedented access to critical information when deployed in respiratory and biodetection devices. “The extreme thinness of nanotubes renders them extremely sensitive to small changes in their chemical environment,” says Alexander Star, the project’s lead researcher. “This quality makes nanotubes ideal for detection applications.”
The sensor theoretically would be cased in a handheld device that asthmatics blow into to determine the nitric oxide content of their breath. Gas levels spike as airways grow inflamed, a symptom of an impending asthma attack. High levels of nitric oxide—up to two-thirds more than normal—may precede an attack by up to three weeks, possibly earlier, depending on the asthma’s severity, according to Star.
Other advantages of the sensor include low power consumption and cost. “Although the design of the sensor is very sophisticated, the cost of carbon nanotubes can be quite inexpensive,” Star says. “And the handheld devices would be much less expensive than the bulky machines used today to detect nitric oxide levels.”
Because of their expense, current nitric oxide detecting machines are only available in outpatient clinics, making them suitable for diagnosis and for gauging the severity of asthma, but impractical for monitoring symptoms. A handheld device incorporating the sensor would be ideal for self-monitoring, says Star. “This invention could allow people with asthma to watch their nitric oxide levels as easily as people with diabetes check their blood sugar with handheld glucose monitors.”
University of Pittsburgh, Pittsburgh, PA