Want Medical Diagnostic Devices? Try Carbon Nanotubes!

Relying on carbon nanotubes, researchers at Oregon State University (OSU; Corvallis) are increasing the speed of biological sensors. By nearly tripling the speed of prototype nanobiosensors, the new technology could further contribute to what designers, manufacturers, and users of medical diagnostic devices have been trying to achieve for a long time--performing lab tests in minutes and speeding medical diagnoses.

Discussed in an article appearing in Lab on a Chip, the research indicates that the key to the new technology is the capability of carbon nanotubes embedded in the surface of a sensor to detect proteins. When a protein lands on them, the nanotubes change their electrical resistance, the extent of which can be measured to determine the presence of proteins. Detectable proteins include serum and ductal protein biomarkers, which may be indicators of breast cancer. The OSU researchers' advance consisted of keeping proteins from sticking to other surfaces. By finding a way to essentially "grease the pipe," they were able to achieve a 2.5-fold increase in the speed of the sensing process.

"With these types of sensors, it should be possible to do many medical lab tests in minutes, allowing the doctor to make a diagnosis during a single office visit," states Ethan Minot, an OSU assistant professor of physics. "Many existing tests take days, cost quite a bit, and require trained laboratory technicians." This approach, he adds, should accomplish the same thing with a hand-held sensor and might cut the cost of an existing $50 lab test to about $1.

The scientists note that further work is needed to improve the selective binding of proteins before the technology can be developed into commercial biosensors.