Jake Rabinowitz, Charishma Cohen, and K. L. Shepard, An Electrically Actuated, Carbon-Nanotube-Based Biomimetic Ion Pump, Nano Letters, DOI: 10.1021/acs.nanolett.9b04552
Single-walled carbon nanotubes (SWCNTs) are well-established transporters of electronic current, electrolyte, and ions. Inthis work, we demonstrate an electrically actuated biomimetic ionpump by combining these electronic and nanofluidic transportcapabilities within an individual SWCNT device. Ion pumping isdriven by a solid-state electronic input, as Coulomb drag couplingtransduces electrical energy from solid-state charge along the SWCNTshell to electrolyte inside the SWCNT core. Short-circuit ioniccurrents, measured without an electrolyte potential difference, exceed 1 nA and scale larger with increasing ion concentrationsthrough 1 M, demonstrating applicability under physiological (∼140 mM) and saltwater (∼600 mM) conditions. The interlayercoupling allows ionic currents to be tuned with the source−drain potential difference and electronic currents to be tuned withthe electrolyte potential difference. This combined electronic−nanofluidic SWCNT device presents intriguing applications as abiomimetic ion pump or component of an artificial membrane.