Nanofluidics: Transport In Chirality-Controlled Carbon Nanotube Porins (CNTPs)

Carbon nanotubes (CNTs) with different chirality are great models to study electronic properties that influence ion transport through single-channel nanotubes. Based on band gap theory, CNTs in different chirality with different curvatures of tube surface may have different conductivity. Herein we report ion transport through chirality-separated pure (6,5), (7,4), and (7,5)/(8,4) CNT porins (CNTPs). Single channel conductance from chirality-pure, yet almost identical in diameter CNTPs indicates that electronic properties have a weak effect on ion transport. Furthermore, we measured ion transport through fluorescence ultrashort nanotubes (FUNs) – functionalized channels with defective walls. These channels have significantly lower conductance compared to the pure (6, 5) CNTPs. Besides, ions can successfully transport through CNTP dispersed by surfactants such as CHAPS and SDOC, the ion conductance of CNTPs is independent of the surfactant used to cut the CNTs.