Self-Assembled Chiral Nanoparticles Superstructures and Identification of Their Collective Optical Activity from Ligand Asymmetry (vol 13, pg 2879, 2019)

Spontaneous self-assembly of chiral nanoparticles (NPs) into stationary fabrication has be well interested in technique investigation and science advancement due to its expected apparent properties via orderly collective behaviors. However, this kind of characterization of assembled nanoparticles superstructure (NPS) is rarely report, and which is distinguished with mono-dispersed chiral NPs. In this work, we used L-cysteine (Cys) as the chiral molecule in form of functional surfactant, which was capped CdS/CdTe NPs and treated as linkage bridges for constructing orderly assembled NPS. Among in circular dichrosim (CD) phenomenon, Cys ligands exhibit related changes in CD absorption while whole molecules solution is treating in different pH controlling procedures. Synthesized chiral NPs are organized into ordered rod-shaped NPS during spontaneous self-assembly process, the CD response of NPS is monitored while in different cultivating times, and it showed a persuasive response appears in sum frequency generation (SFG) spectroscopy. Both of experimental works and theory calculation convey that the ordered stacking of chiral stabilizer and the chirality of NPS, which are identified from chiral molecular status and their collective optical activity originated from ligand asymmetry.