Hybridization kinetics and thermodynamics of DNA adsorbed to individually dispersed single-walled carbon nanotubes

Small. 2007 Sep;3(9):1602-9. doi: 10.1002/smll.200700141.

Abstract

Hybridization of DNA adsorbed to single-walled carbon nanotubes in solution has much slower kinetics than free solution DNA, and can be detected through a blue shift in the near-infrared nanotube fluorescence. Adsorption of the receptor DNA strand to the nanotube surface is consistent with models of polyelectrolyte adsorption on charged surfaces, introducing both entropic (46.8 cal mol(-1) K(-1)) and activation energy (20.4 kcal mol(-1)) barriers to the hybridization, which are greater than free solution values (31.9 cal mol(-1) K(-1) and 12.9 kcal mol(-1)) at 25 degrees C. The increased hybridization barriers on the nanotube result in exceedingly slow kinetics for hybridization with t(1/2)=3.4 h, compared to the free solution value of t(1/2)=4 min. These results have significant implications for nanotube and nanowire biosensors.

Publication types

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

MeSH terms

  • Adsorption
  • Coated Materials, Biocompatible / chemistry
  • Computer Simulation
  • Crystallization / methods
  • DNA / chemistry*
  • DNA / genetics*
  • DNA / ultrastructure
  • In Situ Hybridization / methods*
  • Kinetics
  • Macromolecular Substances / chemistry
  • Materials Testing
  • Models, Chemical*
  • Models, Molecular*
  • Molecular Conformation
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure
  • Nanotechnology / methods*
  • Particle Size
  • Surface Properties
  • Thermodynamics

Substances

  • Coated Materials, Biocompatible
  • Macromolecular Substances
  • DNA