Encoding Enantiomeric Molecular Chiralities on Graphene Basal Planes

Abstract

Graphene has demonstrated broad applications due to its prominent properties. Its molecular structure makes graphene achiral. Here, we propose a direct way to prepare chiral graphene by transferring chiral structural conformation from chiral conjugated amino acids onto graphene basal plane through π-π interaction followed by thermal fusion. Using atomic resolution transmission electron microscopy, we estimated an areal coverage of the molecular imprints (chiral regions) up to 64 % on the basal plane of graphene (grown by chemical vapor deposition). The high concentration of molecular imprints in their single layer points to a close packing of the deposited amino acid molecules prior to "thermal fusion". Such "molecular chirality-encoded graphene" was tested as an electrode in electrochemical enantioselective recognition. The chirality-encoded graphene might find use for other chirality-related studies and the encoding procedure might be extended to other two-dimensional materials.

Chiral Materials: Progress, Applications, and Prospects

“…[ 38 ] Amino acids and their derivatives have moderate molecular sizes and clear structures, so amino acids and their derivatives are often used as chiral selectors in the identification and separation of enantiomers. [ 39 ] Amino acids are the starting substances of proteins, enzymes, and hormones in the living system. They can participate in the normal metabolism and physiological activities of the human body, and have good application value in promoting nutrient absorption, preventing and treating diseases.…”

Chiral Induction in 2D Borophene Nanoplatelets through Stereoselective Boron–Sulfur Conjugation

“…Chirality is ubiquitous in nature ranging from macroscopic to microscopic systems, with implications for biological and physiological processes. − The concept of chirality has therefore infiltrated numerous areas of research including pharmaceuticals, bioengineering, agriculture and biosensing. − Due to their chiroptical activity and self-assembling capabilities, chiral inorganic nanostructures especially have been a key ingredient in optoelectronics, sensors, and enantioselective catalysis. − These biomimetic nanoparticles display both molecular and nanoscale chirality, corresponding to the geometry of surface ligands and of the nanoparticles as a whole. − By unraveling chirality-dependent interactions on the nano- and molecular scale, these developments have helped us better understand how chirality is selected in biological systems and demonstrated the potential for chiral nanostructures in life science. − Some of the widely used chiral two-dimensional (2D) materials toward this direction are graphene, boron nitride, graphitic carbon nitride, transition metal dichalcogenides, phosphorene, etc. , Borophene, a relatively newer addition to the portfolio of 2D nanomaterial, demonstrates unique chemical and metallic properties with varied structural polymorphism. − The polymorphic nature of borophene, is derived from the bonding configurations among boron atoms, which further distinguishes it from other 2D materials and allows for customization of its material properties. , One of the other interesting facts for this emerging boron allotrope is behind its anisotropic Dirac properties that are hypothesized to largely influence biological interactions. − However, imepdiment in imparting chirality to such materials, the challenge of sustainability, purity of enantiomers, solubility, and stability are growing concerns. Scientists have generally used enantioselective organic–inorganic interactions, template-induced synthetic approaches, and photon-induced methods to introduce chirality in nanomaterials. ,…”