Functional single-wall carbon nanotube nanohybrids--associating SWNTs with water-soluble enzyme model systems.
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.
Institute for Physical and Theoretical Chemistry, Egerlandstrasse 3, 91058 Erlangen, Germany. dirk.guldi@chemie.uni-erlangen.de
Dirk M
DM
Guldi
G M Aminur
GM
Rahman
Norbert
N
Jux
Domenico
D
Balbinot
Uwe
U
Hartnagel
Nikos
N
Tagmatarchis
Maurizio
M
Prato
D002412:Cations / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D004798:Enzymes / Q000378:metabolism*; D007501:Iron / Q000737:chemistry; D008665:Metalloporphyrins / Q000737:chemistry / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D015394:Molecular Structure; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011721:Pyrenes / Q000737:chemistry; D012995:Solubility; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry*
D002412:Cations; D004798:Enzymes; D008665:Metalloporphyrins; D037742:Nanotubes, Carbon; D011721:Pyrenes; D014867:Water; D003035:Cobalt; D007501:Iron