Functional single-wall carbon nanotube nanohybrids--associating SWNTs with water-soluble enzyme model systems

J Am Chem Soc. 2005 Jul 13;127(27):9830-8. doi: 10.1021/ja050930o.

Abstract

We succeeded in integrating single-wall carbon nanotubes (SWNTs), several water-soluble pyrene derivatives (pyrene(-)), which bear negatively charged ionic headgroups, and a series of water-soluble metalloporphyrins (MP(8+)) into functional nanohybrids through a combination of associative van der Waals and electrostatic interactions. The resulting SWNT/pyrene(-) and SWNT/pyrene(-)/MP(8+) were characterized by spectroscopic and microscopic means and were found to form stable nanohybrid structures in aqueous media. A crucial feature of our SWNT/pyrene(-) and SWNT/pyrene(-)/MP(8)(+) is that an efficient exfoliation of the initial bundles brings about isolated nanohybrid structures. When the nanohybrid systems are photoexcited with visible light, a rapid intrahybrid charge separation causes the reduction of the electron-accepting SWNT and, simultaneously, the oxidation of the electron-donating MP(8)(+). Transient absorption measurements confirm that the radical ion pairs are long-lived, with lifetimes in the microsecond range. Particularly beneficial are charge recombination dynamics that are located deep in the Marcus-inverted region. We include, for the first time, work devoted to exploring and testing FeP(8)(+) and CoP(8)(+) in donor-acceptor nanohybrids.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cations / chemistry
  • Cobalt / chemistry
  • Enzymes / metabolism*
  • Iron / chemistry
  • Metalloporphyrins / chemistry
  • Metalloporphyrins / metabolism
  • Microscopy, Electron, Transmission
  • Models, Biological
  • Molecular Structure
  • Nanotubes, Carbon / chemistry*
  • Nanotubes, Carbon / ultrastructure
  • Pyrenes / chemistry
  • Solubility
  • Spectrum Analysis
  • Water / chemistry*

Substances

  • Cations
  • Enzymes
  • Metalloporphyrins
  • Nanotubes, Carbon
  • Pyrenes
  • Water
  • Cobalt
  • Iron