Ultrafast proton transport in sub-1-nm diameter carbon nanotube porins

Ramya H. Tunuguntla, Frances I. Allen, Kyunghoon Kim, Allison Belliveau, Aleksandr Noy

Research output: Contribution to journalArticle

73 Scopus citations

Abstract

Proton transport plays an important role in many biological processes due to the ability of protons to rapidly translocate along chains of hydrogen-bonded water molecules. Molecular dynamics simulations have predicted that confinement in hydrophobic nanochannels should enhance the rate of proton transport. Here, we show that 0.8-nm-diameter carbon nanotube porins, which promote the formation of one-dimensional water wires, can support proton transport rates exceeding those of bulk water by an order of magnitude. The transport rates in these narrow nanotube pores also exceed those of biological channels and Nafion. With larger 1.5-nm-diameter nanotube porins, proton transport rates comparable to bulk water are observed. We also show that the proton conductance of these channels can be modulated by the presence of Ca 2+ ions. Our results illustrate the potential of small-diameter carbon nanotube porins as a proton conductor material and suggest that strong spatial confinement is a key factor in enabling efficient proton transport.

Original languageEnglish (US)
Pages (from-to)639-644
Number of pages6
JournalNature Nanotechnology
Volume11
Issue number7
DOIs
StatePublished - Jul 1 2016
Externally publishedYes

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ASJC Scopus subject areas

  • Bioengineering
  • Biomedical Engineering
  • Materials Science(all)
  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Atomic and Molecular Physics, and Optics

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