Aqueous Exfoliation of Transition Metal Dichalcogenides Assisted by DNA/RNA Nucleotides: Catalytically Active and Biocompatible Nanosheets Stabilized by Acid–Base Interactions

Abstract

The exfoliation and colloidal stabilization of layered transition metal dichalcogenides (TMDs) in an aqueous medium using functional biomolecules as dispersing agents have a number of potential benefits toward the production and practical use of the corresponding two-dimensional materials, but such a strategy has so far remained underexplored. Here, we report that DNA and RNA nucleotides are highly efficient dispersants in the preparation of stable aqueous suspensions of MoS and other TMD nanosheets at significant concentrations (up to 5-10 mg mL). Unlike the case of common surfactants, for which adsorption on 2D materials is generally based on weak dispersive forces, the exceptional colloidal stability of the TMD flakes was shown to rely on the presence of relatively strong, specific interactions of Lewis acid-base type between the DNA/RNA nucleotide molecules and the flakes. Moreover, the nucleotide-stabilized MoS nanosheets were shown to be efficient catalysts in the reduction of nitroarenes (4-nitrophenol and 4-nitroaniline), thus constituting an attractive alternative to the use of expensive heterogeneous catalysts based on noble metals, and exhibited an electrocatalytic activity toward the hydrogen evolution reaction that was not impaired by the possible presence of nucleotide molecules adsorbed on their active sites. The biocompatibility of these materials was also demonstrated on the basis of cell proliferation and viability assays. Overall, the present work opens new vistas on the colloidal stabilization of 2D materials based on specific interactions that could be useful toward different practical applications.

Metal‐Based Nanomaterials in Biomedical Applications: Antimicrobial Activity and Cytotoxicity Aspects

“…[ 290 ] Layered TMDs such as MoS 2 , MoSe 2 , MoTe 2 , and WS 2 are the most broadly investigated 2D compounds beyond the graphene family. [ 291,292 ] The TMDs have various properties, ranging from semiconductors such as MoS 2 and WS 2 , insulators such as HfS 2 , semimetals such as WTe 2 and TiSe 2 , to true metals including NbS 2 and VSe 2 . [ 290 ]…”

Functionalized Hybridization of 2D Nanomaterials

“…[105][106][107][108][109] Chitosan exfoliated and decorated MoS 2 nanosheets effectively as a biocompatible near-infrared material in photothermal ablation of cancer. [105][106][107][108][109] Chitosan exfoliated and decorated MoS 2 nanosheets effectively as a biocompatible near-infrared material in photothermal ablation of cancer.…”

“…[106] Sodium alginate was found to be very efficient to produce an unprecedented concentration of WS 2 nanosheets originated from strong interaction of hydrogen bonding and coordination between sodium alginate and WS 2 layers. [106] Recently, Ayán-Varela et al reported the adsorption of DNA/RNA nucleotides on TMDs to exfoliate nanosheets through Lewis acid-base type interactions between nucleotides and nanosheets.…”

Research Progress of the Liquid-Phase Exfoliation and Stable Dispersion Mechanism and Method of Graphene

“…For example, Vashist and Luong (2015) studied target proteins and found that nucleotides DNA/RNA were highly adsorbed onto the surface of electrochemically and thermochemically reduced rGO. Compared with the surfactant dispersion system, although the concentration of graphene was much lower in the biomolecular system than in the surface active system (Seo et al, 2011;Notley, 2012;Zhu et al, 2014), the advantages of the nucleotide (DNA/RNA) dispersion system, such as biocompatibility and low cost, are not comparable with those of other dispersion systems (Georgakilas et al, 2012;Ayan-Varela et al, 2017).…”