Supramolecular Surface Modification and Solubilization of Single‐Walled Carbon Nanotubes with Cyclodextrin Complexation

Abstract

A novel approach to solubilize single-walled carbon nanotubes (SWCNTs) in the aqueous phase is described by employing supramolecular surface modification. We use cyclodextrin complexes of synthetic molecules that contain a planar pyrene moiety or a bent, shape-fitted triptycene moiety as a binding group connected through a spacer to an adamantane moiety that is accommodated in the cyclodextrin cavity. The binding groups attach to the sidewalls of SWCNTs through a pi-pi stacking interaction to yield a supramolecular system that allows the SWCNTs to dissolve in the aqueous phase through the formed hydrophilic cyclodextrin shell. The black aqueous SWCNT solutions obtained are stable over a period of months. They are characterized through absorbance, static, and time-resolved fluorescence spectroscopy as well as Raman spectroscopy, TEM, and fluorescence-decay measurements. Furthermore, the shape-fitted triptycene-based system shows a pronounced selectivity for SWCNTs with a diameter of 1.0 nm.

Enzymatic formation of carbohydrate rings catalyzed by single-walled carbon nanotubes

“…It contains a relatively hydrophobic inner cavity and hydrophilic outer surface [20], which potentially allow for the formation of inclusion complexes with various molecules-organic, inorganic or biological-in the hydrophobic cavity through host-guest recognition. The complexes could facilitate improved stabilization and solubilization of hydrophobic molecules in water [27,28]. CD or starchassisted CNT functionalization is well studied [20,27,28], but aqueous enzymatic formation of CD-SWNT supramolecular assemblies has not been reported.…”

Spatially Controllable DNA Condensation by a Water‐Soluble Supramolecular Hybrid of Single‐Walled Carbon Nanotubes and β‐Cyclodextrin‐Tethered Ruthenium Complexes

“…The supramolecular hybrid in aqueous solution is observed by HR-TEM (Supporting Information, Figure S8), and shows similar images to our former report. [13] AFM section analysis presents the diameter of SWCNT as approximately 0.9 nm and the height of the modified SWCNT domain as approximately 2.2 nm (Figure 4). The difference in their dimension is accordance with the thickness of two layers of cyclodextrin (ca.…”

“…On the basis of our recent report, [13] the aqueous solution of 1 was prepared with b-CD-containing ruthenium complexes by using a modified procedure from the literature. [14] We mixed and finely ground the solid sample to improve the stability of the aqueous solution, and the final product was dialyzed with ultrapure water to ensure the complete removal of excess b-CD-RC and Py-Ad.…”

“…The pyrene derivative with a tethered adamantane group (Py-Ad) and [RuA C H T U N G T R E N N U N G (phen) 2 (b-CD-hophen)]Cl 2 complex (b-CD-RC) were prepared respectively according to the reported procedures. [5,13] The plasmid DNA pUC19 was purchased from Beijing Dingguo Biotechnology Co., Ltd (Beijing, China). The yeast (S. cerevisia) was obtained as a gift from the Department of Agronomy-Forestry Science, Huanghuai University.…”

“…Recently, we reported a supramolecular surface modification of SWCNTs by the inclusion complex of methylated b-cyclodextrin (b-MCD) with adamantane derivatives (Py-Ad) that are tethered with a pyrene moiety. [13] The formation of the SWCNT-Py-Ad-b-MCD supramolecular hybrid results in the water-solubilization of SWCNTs, in which the SWCNT is the core, and the adamantane-cyclodextrin complexes are the water-soluble shell/corona. If we replace the b-MCD with b-CD-tethered ruthenium com-…”