Via press release, researchers at Oak Ridge National Lab working toward a low-cost DNA sequencing tool for medical diagnostics have proposed using a single-walled carbon nanotube to thread a single strand of DNA from one reservoir to another, analyzing and sequencing the DNA in the process.

In such a device, the negatively charged DNA material, which is immersed in an electrolytic fluid, is propelled through the nanotube by an electric field.

When the current flowing through the nanotube was measured, researchers were surprised by the current of electrolytic ions that was much higher than any prediction.

Arizona State University’s Predrag Krstic and former ORNL researcher Sony Joseph performed atomistic molecular and fluid dynamics simulations at the University of Tennessee’s National Institute for Computational Sciences, located at ORNL.

Krstic and Joseph, in a paper published with their Arizona State and Columbia collaborators in the Jan. 1, 2010, issue of Science, attributed the mysterious current surge to the “slipping” of water molecules through the perfect and hydrophobic inner surface of the carbon nanotube and to trapped electrical charge.

Understanding such phenomena is key to the development of these single-molecule-detection instruments that would be inexpensive enough to become common in doctor’s offices.

“This is an example of how the front of science is increasingly multidisciplinary, with contributions by experimentalists and theorists in atomic and solid-state physics, chemistry, biology and engineering,” says Predrag.