Nanowire Oriented On-Surface Growth of Chiral Cystine Crystalline Nanosheets

Abstract

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 μm(2)). 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.

Ultralarge Single-Layer Porous Protein Nanosheet for Precise Nanosize Separation

“…However, the obtained TMVm nanosheets through such a self-assembly process usually had a small size (width <500 nm), which is not suitable for the use of separation (Figure S2). Moreover, we found in a prior work that ultrathin cystine crystalline nanosheets with finely controlled thickness and micrometer-scale dimensions could be created through a nanowire-oriented on-surface growth strategy, where a dense and interlaced Cu­(OH) 2 nanowire-wrapped copper grid was utilized as a template . In this environment, a trace amount of Cu 2+ ions in several micromoles was released from Cu­(OH) 2 nanowires into the reaction solution slowly and evenly, which catalyzed the formation of cysteine into cystine nanosheets.…”

“…Moreover, we found in a prior work that ultrathin cystine crystalline nanosheets with finely controlled thickness and micrometerscale dimensions could be created through a nanowire-oriented on-surface growth strategy, where a dense and interlaced Cu(OH) 2 nanowire-wrapped copper grid was utilized as a template. 40 In this environment, a trace amount of Cu 2+ ions in several micromoles was released from Cu(OH) 2 nanowires into the reaction solution slowly and evenly, which catalyzed the formation of cysteine into cystine nanosheets. Interestingly, such a slowly released Cu 2+ -catalyzed on-surface growth strategy can also be used to catalyze the S−S bond on TMVm disks and promote the formation of ultralarge single-layer TMVm nanosheets with a high yield (for the control experiment, see Figure S3).…”