Induction of Chirality in Two-Dimensional Nanomaterials: Chiral 2D MoS₂ Nanostructures

Abstract

Two-dimensional (2D) nanomaterials have been intensively investigated due to their interesting properties and range of potential applications. Although most research has focused on graphene, atomic layered transition metal dichalcogenides (TMDs) and particularly MoS2 have gathered much deserved attention recently. Here, we report the induction of chirality into 2D chiral nanomaterials by carrying out liquid exfoliation of MoS2 in the presence of chiral ligands (cysteine and penicillamine) in water. This processing resulted in exfoliated chiral 2D MoS2 nanosheets showing strong circular dichroism signals, which were far past the onset of the original chiral ligand signals. Using theoretical modeling, we demonstrated that the chiral nature of MoS2 nanosheets is related to the presence of chiral ligands causing preferential folding of the MoS2 sheets. There was an excellent match between the theoretically calculated and experimental spectra. We believe that, due to their high aspect ratio planar morphology, chiral 2D nanomaterials could offer great opportunities for the development of chiroptical sensors, materials, and devices for valleytronics and other potential applications. In addition, chirality plays a key role in many chemical and biological systems, with chiral molecules and materials critical for the further development of biopharmaceuticals and fine chemicals, and this research therefore should have a strong impact on relevant areas of science and technology such as nanobiotechnology, nanomedicine, and nanotoxicology.

Spectroscopy for model heterogeneous asymmetric catalysis

“…Different aspects of this phenomenon have been elucidated frequently in multiple excellent contributions for metallic [84][85][86][87][88][89][90][91][92][93][94][95][96][97][98] and semiconducting nanoparticles. [99][100][101][102][103][104][105][106][107][108][109] Ma and coworkers summarized most of the works related to chirality transfer in 2017 where they considered four types of chirality in nanoparticles and gave examples of each. 110 The four types are the following: (1) geometrical chirality of the inorganic core, (2) geometrical chirality of the inorganic surface (also called chiral footprint), (3) geometrical chirality of the protecting shell, and (4) chiral field effect.…”

Chirality‐Driven Transportation and Oxidation Prevention by Chiral Selenium Nanoparticles

“…For instance, chiral 2D MoS 2 was fabricated by introducing the chiral ligands cysteine and penicillamine during the liquid exfoliation of MoS 2. Further, surface‐anchored chiral molecules on nanoparticles exert different chiral preferences to modulate cellular uptake and cell adhesion in bacterial and mammalian cells, which influence the biological effects of the nanoparticles on cytotoxicity, autophagy, gene editing, and metabolism . Gong et al., demonstrated that the d ‐glutamic acid modified graphene quantum dots showed highly selective penetration into the bacterial cell membrane over mammalian cells.…”

All-optical reconfigurable chiral meta-molecules

“…These chiral molecules and their mirror images (enantiomers) exhibit opposite handedness when interacting with circularly polarized light, as well as different chemical and biological performance. Inspired by chiral molecular structures, researchers are developing strategies to build artificial chiral materials by mimicking molecular structures using functional materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Specifically, metal nanomaterials exhibit tailorable optical properties upon excitation of surface plasmons and become one of the most promising components to realize of chiral optical metamaterials [15,16].…”