Transparent and Conducting Graphene–RNA‐Based Nanocomposites

Abstract

Ribonucleic acid (RNA) is proposed as a nonionic surfactant for the efficient exfoliation of graphite in thin flakes of few-layer graphene and the subsequent preparation of transparent and conducting thin films. Parameters such as the type of RNA used and the size of starting graphite flakes are demonstrated to be essential for obtaining RNA-graphene thin films of good quality. A model explaining the exfoliation of graphene by RNA in water is suggested. A number of post- and predeposition treatments (including thermal annealing, functionalization of the films, and the preoxidation of graphite) are critical to improve the performance of graphene-RNA nanocomposites as transparent conductors. The study establishes an ideal link between RNA and graphene, the fundamental building blocks for nanobiology and carbon-based nanotechnology.

Biomolecule-assisted exfoliation and dispersion of graphene and other two-dimensional materials: a review of recent progress and applications

“…This was probably one of the reasons why early efforts on the direct exfoliation of graphite assisted by ssDNA relied on the covalent incorporation of a pyrene moiety at one end of the nucleic acid strand, so that the strong pyrene-graphene interaction would facilitate the immobilization of the biomolecule on the 2D structure. 80 Nevertheless, subsequent studies demonstrated that nucleic acids are able to exfoliate and colloidally stabilize both graphene 81,82 and other binding energies in the ~65-90 kJ mol -1 range and following the order G > A > T > C > U. 84 MD simulations have also been carried out to investigate the dispersion of graphene flakes by short ssDNA segments (3-18 nucleobases) in aqueous medium.…”

“…For example, thin films made from RNA-exfoliated graphene flakes have demonstrated a performance as transparent conductors that is comparable to that of graphene films obtained using synthetic surfactants. 81 Likewise, graphene-Au nanoparticle hybrids with potential utility in sensing or catalysis have been prepared through specific binding of ssDNA-stabilized graphene flakes to Au NPs labeled with complementary ssDNA strands. 80 In the biomedical realm, ssDNAexfoliated WS 2 and WSe 2 flakes have been very recently investigated for their antibacterial effect.…”

Graphene Thin Films and Graphene Decorated with Metal Nanoparticles

“…Surfactants such as sodium dodecylbenzene sulfonate (SDBS) can be used to enhance graphite exfoliation without the use of strong oxidation treatments to saturate the graphite layers with oxygen functional groups and promote water solubility. RNA has been used as a low cost and biocompatible surfactant to disperse weakly oxidized graphite in water [4]. The use of an additional material to aid in exfoliation allows the graphite to be dispersed in water without being strongly oxidized, and therefore does not require reduction to become conductive.…”

“…Recent advances in solution processing of graphite have been focussed on limiting the use of strong acid treatments to control the oxidation, and instead make use of surfactants to aid the exfoliation process. Ribonucleic acid (RNA) has been used by Sharifi et al [4] as an effective aqueous surfactant to exfoliate graphite that is weakly oxidized in comparison to GO before reduction. Weakly oxidized graphene of this type has been shown to be dispersible in water due to RNA absorption ( Figure 1) and is conductive as-deposited from solution without further treatment to remove oxygen functional groups.…”

Experimental and Theoretical Investigations on the Ferroelectricity of Graphene Oxides

“…Graphene, a single graphite layer, has attracted considerable research interests both in experiment and theory due to its novel physical properties, [1][2][3][4] such as high carrier mobility [5] and room-temperature quantum hall effect. [6] Thanks to its extraordinary properties, this new material has an important role in semiconductor devices.…”