Nanowire Oriented On-Surface Growth of Chiral Cystine Crystalline Nanosheets

Exploration of an effective route to achieve the controlled growth of two-dimensional (2D) molecular crystal is of scientific significance yet greatly underdeveloped due to the complexity of weak intermolecular interactions, thus leading to difficulty of inducing anisotropic 2D growth. We report here a facile nanowire oriented on-surface growth strategy for the fabrication of cystine crystalline nanosheets with finely controlled thickness (1.1, 1.9, 2.9, and 4.8 nm which correspond to one layer, two layers, three layers, and five layers of crystal cystine, respectively) and large areas (>100 μm²). The cystine crystalline nanosheets display chirality delivered by chiral cysteine monomers, either l-cysteine or d-cysteine. The chiral nanosheets with structural precision and chemical diversity could serve as a novel 2D platform for constructing advanced hybrid materials.