Chiral nanocrystals grown from MoS2 nanosheets enable photothermally modulated enantioselective release of antimicrobial drugs

Abstract

The transfer of the concept of chirality from molecules to synthesized nanomaterials has attracted attention amongst multidisciplinary teams. Here we demonstrate heterogeneous nucleation and anisotropic accumulation of Au nanoparticles on multilayer MoS2 planes to form chiroptically functional nanomaterials. Thiol amino acids with chiral conformations modulate asymmetric growth of gold nanoarchitectures on seeds of highly faceted Au/MoS2 heterostructures. Consequently, dendritic plasmonic nanocrystals with partial chiral morphologies are synthesized. The chirality of dendritic nanocrystals inherited from cysteine molecules refers to the structural characteristics and includes specific recognition of enantiomeric molecules. With integration of the intrinsic photothermal properties and inherited enantioselective characteristics, dendritic Au/MoS2 heterostructures exhibit chirality-dependent release of antimicrobial drugs from hydrogel substrates when activated by exogenous infrared irradiation. A three-in-one strategy involving synthesis of chiral dendritic heterostructures, enantioselective recognition, and controlled drug release system is presented, which improves nanomaterial synthetic technology and enhances our understanding of crucial chirality information.

Tracking the Growth of Chiral Plasmonic Nanocrystals at Molybdenum Disulfide Heterostructural Interfaces

“…In the FFT figures, the interplanar spacing was roughly in accordance to that found in standard samples (MoS 2 : PDF#97-003-8401). The result of the obtained FFT simulation was in accordance with the energy dispersive spectroscopy (EDS) mapping of nanostructures . The formation of crack structures was ascribed to the different growths of gold nanostructures on the top and bottom MoS 2 surfaces.…”

“…The layered structures of MoS 2 with the coverage of gold atoms, like a sandwich, were observed. Compared with the elemental distribution in the EDS and FFT results, the composition of the sandwich-shaped intermediate is conformed . Consequently, we supposed that in comparison to the homogeneous nucleation, Au atoms preferred to settle down at MoS 2 heterostructural surfaces (Figure f).…”

“…Therefore, additive MoS 2 nanosheets served as seeds, and consequently, the growth of Au nanostructures in the presence of MoS 2 seeds was proposed. Our previous studies indicated that the growth of Au nanostructures on heterostructural MoS 2 substrates was influenced by a series of coexisting metal ions and biomolecules, such as mercury ions and thiol compounds. ,− From the absorption spectra, it was found that with the addition of 0.4 μM l -cysteine, the peak wavelengths of the CTAB-Au + solution and MoS 2 reaction products declined from 656 nm to 606 nm. When the l -cysteine concentrations increased from 0.4 to 1.6 μM, remarkable red shifts of wavelengths were observed from the absorption spectra and a series of colorful products dispersed in aqueous solution were noticed (Figure S3).…”

“…Compared with the elemental distribution in the EDS and FFT results, the composition of the sandwich-shaped intermediate is conformed. 38 Consequently, we supposed that in comparison to the homogeneous nucleation, Au atoms preferred to settle down at MoS 2 heterostructural surfaces (Figure 4f). These nanostructures were caused by the diffusion of Au atoms growing on the surfaces.…”

“…The result of the obtained FFT simulation was in accordance with the energy dispersive spectroscopy (EDS) mapping of nanostructures. 38 The formation of crack structures was ascribed to the different growths of gold nanostructures on the top and bottom MoS 2 surfaces. The layered structures of MoS 2 with the coverage of gold atoms, like a sandwich, were observed.…”