Synthesis and Characterization of Nucleobase−Carbon Nanotube Hybrids

Abstract

We report the synthesis and characterization of adenine-single-walled carbon nanotube (SWCNT) hybrid materials, where for the first time nucleobases are covalently attached to the exosurface of SWCNTs. The structural properties of all hybrids have been characterized using usual spectroscopic and microscopic techniques. The degree of functional groups for functionalized SWCNTs (f-SWCNTs) 2a and 2b is one adenine group for each 26 and 37 carbon atoms, respectively. Solid-state magic angle spinning (13)C NMR spectroscopy (MAS NMR) and electrochemistry have been also applied for the characterization of these f-SWCNTs. AFM images of f-SWCNT 2b showed an interesting feature of horizontally aligned nanotubes along the surface when deposited on highly oriented pyrolytic graphite surface. Furthermore, we evaluated the coordinating ability of these hybrid materials toward silver ions, and interestingly, we found a pattern of silver nanoparticles localized over the surface of the carbon nanotube network. The presence of aligned and randomly oriented CNTs and their ability to coordinate with metal ions make this class of materials very interesting for applications in the development of novel electronic devices and as new supports for different catalytic transformations.

A versatile, solvent-free methodology for the functionalisation of carbon nanotubes

“…These changes in dispersive and specific surface character are sufficient to alter the dispersion behavior, markedly. Compared to the parent material, the dispersibility of the LMA-grafted CNTs in butyl acetate increased by a factor of 45 ten, from 3 to 35 mg/L (Figure 2(c) and (e)), but substantially decreased by a factor of five in ethanol (Table 2). These differences in dispersibility were even more pronounced when the LMA-grafted product was compared to the "airexposed"control sample (Table 1) which has a relatively less 50 polar surface than the parent material.…”

“…For comparative reasons, these washing steps were also applied to the products synthesized using the gas-phase setup. The 45 washing procedure was a requirement for the detailed fundamental study in this paper; for application, simple removal and recovery of excess reactant via evaporation under vacuum, without using any solvents, should be sufficient. Futher experimental details can be found in the ESI.…”

“…[10][11][12] For these 40 reasons, strategies for the covalent functionalisation of CNTs have been intensively explored in recent years; 12 numerous wet-chemical reactions are available, allowing the introduction of a wide range of functional surface groups. 11,13 Examples include the chemical derivatisation of oxygen- 45 containing functional groups at defect sites, e.g. through classical amidation or esterfication reactions, 14 and direct functionalisation of the graphitic CNT sidewalls, such as reactions with nitrenes, 15 carbenes 16 and diazonium salts.…”

“…Although a one-toone correlation is unlikely for steric and other reasons, the location of the gold colloids in Figure 6 visualizes the distribution of the grafting sites on the CNT surface. Grafting 45 occurs along the whole length of the nanotubes and is probably associated with the presence of graphene edges and defects sites in the CNT sidewalls. Transmission electron microscopy studies (not shown) failed to show a conclusive relationship between the gold nanoparticles location and 50 defect structures probably due to the difficulty of imaging all types of defects in the relevant orientation.…”

Dispersion corrected DFT approaches for anharmonic vibrational frequency calculations: nucleobases and their dimers

“…[1][2][3][4][5][6][7][8] . A comprehensive analysis of the properties of these systems could be very useful for designing highly biocompatible materials and specific biosensors [9][10][11][12][13][14] .…”