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Chiral AuCuAu Heterogeneous Nanorods with Tailored Optical Activity
Author(s) -
Wang Juncai,
Wu Xiaoling,
Ma Wei,
Xu Chuanlai
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202000670
Subject(s) - materials science , nanorod , chirality (physics) , circular dichroism , plasmon , nanotechnology , crystallography , optoelectronics , symmetry breaking , chemistry , chiral symmetry breaking , physics , quantum mechanics , nambu–jona lasinio model
Here, a facile wet‐chemistry route for the selective growth of crystalline copper (Cu) along the sides of gold nanorods (Au NRs) in the presence of a hexadecylamine (HDA) is reported. The resulting heterostructures feature part etching of copper by galvanic replacement reaction and form crystalline AuCu alloy metal on one side of the Au NRs. By virtue of the dipeptide (cysteine‐phenylalanine, Cys‐Phe) ligand used during synthesis, the AuCuAu heteronanorods (HNRs) exhibit strong circular dichroism (CD) in the wavelength range of 400–1000 nm. The plasmonic chirality can be tailored by increasing the length of the Au NRs, the scale of Cu nanocrystals on the Au NRs, and the amount of gold chloride for postgrowth, resulting in an anisotropy factor ( g factor) as high as 0.57 × 10 −2 . The strong CD signals are attributed to the local electromagnetic field. Under circular polarized light (CPL) illumination, the chiral plasmonic AuCuAu nanostructure exhibits high efficiency for light polarization dependent reactive oxygen species ( 1 O 2 ) that is 22.31 times that of Au NRs. The results of this study demonstrate that the chiral enantiomer provides a chirality dependent avenue for highly efficient phototherapy.