Carbon Nanotube–Nucleobase Hybrids: Nanorings from Uracil‐Modified Single‐Walled Carbon Nanotubes

Abstract

Single-walled carbon nanotubes (SWCNTs) have been covalently functionalized with uracil nucleobase. The hybrids have been characterized by using complementary spectroscopic and microscopic techniques including solid-state NMR spectroscopy. The uracil-functionalized SWCNTs are able to self-assemble into regular nanorings with a diameter of 50-70 nm, as observed by AFM and TEM. AFM shows that the rings do not have a consistent height and thickness, which indicates that they may be formed by separate bundles of CNTs. The simplest model for the nanoring formation likely involves two bundles of CNTs interacting with each other via uracil-uracil base-pairing at both CNT ends. These nanorings can be envisaged for the development of advanced electronic circuits.

Immobilization of double functionalized carbon nanotubes on glassy carbon electrodes for the electrochemical sensing of the biotin–avidin affinity

“…Thus, in view of facilitating their solubility and their manipulation, many methods have been developed, including sidewall functionalization [2,[14][15][16], p-p stacking with aromatic molecules [2,16], addition of surfactants [17][18][19][20] and dispersion in non-conventional solvents, such as ionic liquids [21][22][23][24][25] and Nafion [26,27]. In this context, the covalent functionalization of CNTs with biologically relevant molecules such as nucleobases [28][29][30] and oligonucleotides [31][32][33] appears as an original approach to produce hybrid materials for various sensing and biomedical applications ranging from nanodevices, gene therapy, and drug delivery to membrane separation [34][35][36]. Interestingly, such hybrid materials could also give rise to well-defined supramolecular architectures driven by hydrogen bonding interactions.…”

Characterizing Covalently Sidewall-Functionalized Single-Walled Carbon Nanotubes by Using1H NMR Spectroscopy

“…5,20-23 Solid phase magic angle spinning NMR spectroscopy has also been used to confirm covalent functionalization of nanotubes, 24-28 but this does not allow unambiguous assignment of the functional groups bound to the nanotubes. 22 Studies of covalently functionalized SWCNTs using solution-based techniques have determined 7,29,30 performance characteristics, such as efficacy and selectivity. NMR studies of functionalized SWCNTs in solution afford direct structural information about the functionalities.…”

Surface modification and pattern formation by nucleobases and their coordination complexes

“…High resolution studies of guanine self-organization have been carried out on surfaces such as HOPG, Cu (111), and Au(111).…”

“…Although HOPG is a common substrate for nucleobase organization studies, surfaces such as Au (111), Cu (110) and others are also used to address specic questions. For example, adenine exhibited formation of well-ordered 2D islands on Au(111) revealing two discerning structural possibilities: one of the coexisting phases displayed two adenines per unit cell, while the other presented four adenine molecules, when annealed at 370 K (Fig.…”