Nanotube sidewall covalent attachments

Accordingly, many reactions can be performed on the sidewalls of the CNTs, such as halogenation, hydrogenation, radical, electrophilic and nucleophilic additions, and so on [25, 37, 39, 42-44]. Exhaustively explored examples are the nitrene cycloaddition, the 1,3-dipolar cycloaddition reaction (with azomethinylides), radical additions using diazonium salts or radical addition of aromatic/phenyl primary amines. The aryl diazonium reduction can be performed by electrochemical means by forming a phenyl radical (by the extrusion of N2) that couples to a double bond [44]. Similarly, electrochemical oxidation of aromatic or aliphatic primary amines yields an amine radical that can be added to the double bond on the carbon surface. The direct covalent attachment of functional moieties to the sidewalls strongly enhances the solubility of the nanotubes in solvents and can also be tailored for different... 

Pristine carbon nanotubes are extremely hydrophobic and insoluble in aqueous solutions, which is necessary for biological applications. Many efforts were put forth to increase the aqueous solubility of carbon nanotubes using sidewall covalent modification or dispersion with surfactants. In order to solubilize carbon nanotubes in aqueous solution, it is necessary to attach a hydrophilic coating. This can be done in two fundamental... 

For the experiment, the SWNT-FETs were prepared using standard chemical vapor deposition technique. Aptamer immobilization was performed by first modifying the sidewall of the carbon nanotube with CDI-Tween. While the Tween component was bound to the carbon nanotube sidewall through hydrophobic interactions, the carbodii-midazole (GDI) moiety was used to covalently attach the S amine group of the thrombin aptamer. Then, the devices were allowed to react with a (100 pM) thrombin... 

---