Experimental measurements in single-nanotube fluidic channels

Abstract

Technologies for detecting and analyzing a single molecule help us understand and engineer numerous phenomena observed in nature. Carbon nanotubes (CNTs) are highly efficient molecular conduits due to their atomically smooth surface. Because of their small diameters, comparable to the size of a single molecule, even a single blocking molecule can obstruct CNT fluidic channels. Analyzing these pore-blocking events in CNTs therefore enables single-molecule studies. The high-aspect ratios of CNT channels, which extend the time scale of transport, allow for studying molecular transport that is too fast to record in other systems. Both theoretical studies and ensemble experimental measurements have verified the enhanced flow of various ions and molecular species in CNTs. Experimental measurements of a single-CNT fluidic channel, however, have only recently begun, demonstrating the detection of individual DNA, polymer, and alkali-metal ions. This article reviews recent advances in single-nanotube fluidic channels with a focus on experimental measurements.