title: Hybridization kinetics and thermodynamics of DNA adsorbed to individually dispersed single-walled carbon nanotubes.
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.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Esther S
authors.initials: ES
authors.lastname: Jeng
authors.forename: Paul W
authors.initials: PW
authors.lastname: Barone
authors.forename: John D
authors.initials: JD
authors.lastname: Nelson
authors.forename: Michael S
authors.initials: MS
authors.lastname: Strano
mesh_terms: D000327:Adsorption; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods; D004247:DNA / Q000737:chemistry* / Q000235:genetics* / Q000648:ultrastructure; D017403:In Situ Hybridization / Q000379:methods*; D007700:Kinetics; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties; D013816:Thermodynamics