Nanopores are channels that researchers can create in a thin membrane, one nanometer in diameter, through which nucleic acid or other molecules can pass. As a molecule passes through, its molecular composition is translated into electronic signals.
The electronic signals are like a stream of numbers that can then be analyzed to deduce properties about the molecules. This can potentially be accomplished with nanopores much faster and cheaper than with current DNA-sequencing methods. But so far, the technique has been limited by the difficulty of making nanopores that can detect nucleic acid sequences with high accuracy.
The researchers, led by the University of Illinois at Chicago, have discovered how to make nanopores that are highly selective for nucleic acids, based on insights gained by using advanced computer modeling and experimental techniques. They demonstrated the use of molecular recognition to tune the selectivity and sensitivity of nanopores for nucleic acids.
"We wanted to be able to control this selectivity," said study author William Schoch, UIC associate professor of mechanical and industrial engineering. "It turns out that by changing the molecular building block composition of these channels, we can actually engineer them to be much more selective for target molecules. This is what we didn't know before."
The researchers made their channels using DNA origami—a method by which DNA is folded into any given arrangement or shape. In doing so, they were able to introduce chemical groups that specifically bind nucleic acid strands, but have little interaction with other types of molecules.
As they fine-tune their approach, the researchers believe that they can greatly increase the accuracy of the measurements, opening the door to a revolutionary way of sequencing DNA.
The research team includes University of Illinois at Chicago, University of California, Berkeley, and California State University, Long Beach, as well as researchers from China and Saudi Arabia.
