Related Experiment Video
Updated: Aug 7, 2026

Localization and Relative Quantification of Carbon Nanotubes in Cells with Multispectral Imaging Flow Cytometry
Published on: December 12, 2013
Nucleic acid transport through carbon nanotube membranes
1Laboratory of Chemical Physics, Building 5, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA.
Abstract:
We study the electrophoretic transport of single-stranded RNA molecules through 1.5-nm-wide pores of carbon nanotube membranes by molecular dynamics simulations. From approximately 170 individual RNA translocation events analyzed at full atomic resolution of solvent, membrane, and RNA, we identify key factors in membrane transport of biopolymers. RNA entry into the nanotube pores is controlled by conformational dynamics, and exit by hydrophobic attachment of RNA bases to the pores. Without electric field, RNA remains hydrophobically trapped in the membrane despite large entropic and energetic penalties for confining charged polymers inside nonpolar pores. Differences in RNA conformational flexibility and hydrophobicity result in sequence-dependent rates of translocation, a prerequisite for nanoscale separation devices.
Related Concept Videos
The Significance of Membrane Transport
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Primary Active Transport
Nuclear Protein Sorting
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Directionality of Nuclear Transport
Introduction to Membrane Traffic
The transport of soluble and membrane proteins is mediated by transport vesicles that collect cargo from one cellular compartment and deliver it to another by fusing with the target organelle membrane. The Rab...
Facilitated Diffusion
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...

