A One‐Step Chemical Strategy for the Formation of Carbon Nanotube Junctions in Aqueous Solution: Reaction of DNA‐Wrapped Carbon Nanotubes with Diazonium Salts

Abstract

A single‐step chemical strategy allows the formation of single‐walled carbon nanotube (SWCNT) molecular junctions in aqueous solution. SWCNTs were first wrapped with DNA to be water soluble and solution processable. Diazonium salts, which have been shown to react spontaneously with carbon nanotubes in water at room temperature, were then employed to covalently link SWCNT segments. The DNA wrapping of the nanotubes acted as a protective layer that limits the functionalization predominantly to the nanotube terminal ends, therefore allowing the assembly of linear SWCNT junctions. Upon increasing the concentration of the linker, we observed first the formation of side‐to‐end junctions, and eventually the assembly, through side‐to‐side interactions, of SWCNTs into bundles. This approach demonstrates the possibility of tuning the formation of linear and branched carbon nanotube junctions that in turn is of importance for the sustainable fabrication of solution‐processable CNT‐based nanoscale systems and devices.

Growth, Properties, and Applications of Branched Carbon Nanostructures

“…In recent years, environmental awareness has fostered increasing interest in the development of green production methods for carbon nanostructures [24] and their functionalization with virtually zero waste generation [25]. Diazonium salts have been proposed as covalent linkers for the tips of SWCNTs that were previously wrapped in DNA to protect the sidewalls from undesired functionalization, thus enabling the preferential crosslinking of the CNT ends in water and at room temperature [26]. Environmentally-friendly carbon sources, such as vegetable oils, have also been used to produce b-CNTs [27].…”

Quantendefekte als Werkzeugkasten für die kovalente Funktionalisierung von Kohlenstoffnanoröhren mit Peptiden und Proteinen

“…In den letzten Jahren wurde über eine Reihe verschiedener Sauerstoff‐ und Aryl‐Defekte berichtet, die nun sehr vielversprechende Werkzeuge für die Erzeugung von helleren/modifizierten SWCNTs, pH‐ or Saccharid‐Sensoren, kurzen fluoreszierenden SWCNTs für die hochauflösende Mikroskopie oder Einzelphotonenquellen für das Quanten‐Computing sind . Darüber hinaus verschiebt dieses neue Defekt‐induzierte Fluoreszenzsignal die Emission noch weiter in das Biotransparenzfenster, was zu noch besseren Gewebepenetrationseigenschaften führt …”

“…[30] Diese Technik ermçglichte auch die Abstimmung der Defektfluoreszenz sowohl in Bezug auf die Intensitäta ls auch auf die Emissionswellenlänge über verschiedene Substituenten am Aryl/Alkyl-Defekt. [31][32][33][34] In den letzten Jahren wurde über eine Reihe verschiedener Sauerstoff-und Aryl-Defekte berichtet, die nun sehr vielversprechende Werkzeuge fürd ie Erzeugung von helleren/modifizierten SWCNTs, [31,35,36] pH- [37] or Saccharid [38] -Sensoren, kurzen fluoreszierenden SWCNTs fürd ie hochauflçsende Mikroskopie [39] oder Einzelphotonenquellen für das Quanten-Computing sind. [40,41] Darüber hinaus verschiebt dieses neue Defekt-induzierte Fluoreszenzsignal die Emission noch weiter in das Biotransparenzfenster,w as zu noch besseren Gewebepenetrationseigenschaften führt.…”

Quantum Defects as a Toolbox for the Covalent Functionalization of Carbon Nanotubes with Peptides and Proteins

“…In the last years, a number of different oxygen and aryl defects were reported that are now very promising tools for the generation of brighter/modified SWCNTs, pH and saccharide sensors, short fluorescent SWCNTs for superresolution microscopy, and single‐photon sources for quantum computing . Furthermore, this new defect‐induced fluorescence feature moves the emission even further into the biotransparency window, leading to even better tissue penetration properties …”

“…[30] This technique also enabled tuning of the defect fluorescence both in terms of intensity and emission wavelength via different substituents on the aryl/alkyl defect. [31][32][33][34] In the last years,an umber of different oxygen and aryl defects were reported that are now very promising tools for the generation of brighter/modified SWCNTs, [31,35,36] pH [37] and saccharide [38] sensors,s hort fluorescent SWCNTs for superresolution microscopy, [39] and single-photon sources for quantum computing. [40,41] Furthermore,t his new defect-induced fluorescence feature moves the emission even further into the biotransparencywindow,leading to even better tissue penetration properties.…”