Silver Cholesteric Liquid Crystalline: Shape-Dependent Assembly and Plasmonic Chiroptical Response

摘要

A novel silver cholesteric liquid crystalline (CLC) colloidal suspension has been fabricated by a shape-dependent self-assembly process via van der Waals and electrostatic interactions. The circular dichroism (CD) spectra show that the cysteine molecules have a strong effect on the as-obtained silver CLC structure, albeit it is very stable in the presence of many other kinds of amino acid molecules. The original silver CLC structure can be completely dissociated as soon as the concentration of cysteine solution arrives at a critical value. Furthermore, the cysteine molecules can translate their chirality to the silver nanorods (NRs) and silver nanoplates (NPs) by strong S—Ag bonds to form two novel chiral silver—cysteine nanocrystals, respectively. The colloidal suspension of silver—cysteine hybrid nanorods shows a much stronger CD intensity than the colloidal suspension of silver—cysteine hybrid nanoplates do, which can be attributed to its unique anisotropy of geometry and superficial constitution.