Effects of functionalized and nonfunctionalized single-walled carbon nanotubes on root elongation of select crop species

Jaclyn E. Cañas, Monique Long, Shawna Nations, Rodica Vadan, Lenore Dai, Mingxiang Luo, Ramya Ambikapathi, E. Henry Lee, David Olszyk

Research output: Contribution to journalArticle

267 Scopus citations


Single-walled carbon nanotubes have many potential beneficial uses, with additional applications constantly being investigated. Their unique properties, however, create a potential concern regarding toxicity, not only in humans and animals but also in plants. To help develop protocols to determine the effects of nanotubes on plants, we conducted a pilot study on the effects of functionalized and nonfunctionalized single-walled carbon nanotubes on root elongation of six crop species (cabbage, carrot, cucumber, lettuce, onion, and tomato) routinely used in phytotoxicity testing. Nanotubes were functionalized with poly-3-aminoben-zenesulfonic acid. Root growth was measured at 0, 24, and 48 h following exposure. Scanning-electron microscopy was used to evaluate potential uptake of carbon nanotubes and to observe the interaction of nanotubes with the root surface. In general, nonfunctionalized carbon nanotubes affected root length more than functionalized nanotubes. Nonfunctionalized nanotubes inhibited root elongation in tomato and enhanced root elongation in onion and cucumber. Functionalized nanotubes inhibited root elongation in lettuce. Cabbage and carrots were not affected by either form of nanotubes. Effects observed following exposure to carbon nanotubes tended to be more pronounced at 24 h than at 48 h. Microscopy images showed the presence of nanotube sheets on the root surfaces, but no visible uptake of nanotubes was observed.

Original languageEnglish (US)
Pages (from-to)1922-1931
Number of pages10
JournalEnvironmental Toxicology and Chemistry
Issue number9
StatePublished - Sep 1 2008
Externally publishedYes



  • Carbon nanotubes
  • Manufactured nanomaterials
  • Phytotoxicity
  • Root elongation

ASJC Scopus subject areas

  • Environmental Chemistry
  • Health, Toxicology and Mutagenesis

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