title: Structural and optical control of DNA-mediated Janus plasmonic nanostructures.
abstract: The broken symmetry of Janus nanostructures (JNs) provides a distinctive means to express drastically different chemical and physical characters within a single particle and acquire emergent properties usually inconceivable for homogeneous or symmetric nanostructures. In spite of their tremendous application potential, considerable challenges are encountered in identifying pathways to synthesize or assemble JNs with a controllable geometry and morphology. Here, we exploit the reverse process of growth, i.e. silver etching, to quantitatively control the structural and optical properties of the DNA-mediated Au-Ag JNs. The transmission electron microscopy and optical measurements, along with numerical simulations, present a comprehensive view of the etching dynamics and a detailed analysis of the influencing factors that provide handles for regulating the silver etching rate and progress. In addition, a novel type of composite JN is proposed and a model system is designed and engineered through dynamical control of the etching and DNA-hybridization processes.
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Xu
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn.
authors.forename: Geng
authors.initials: G
authors.lastname: Wang
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn.
authors.forename: Jianlei
authors.initials: J
authors.lastname: Shen
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn.
authors.forename: Heping
authors.initials: H
authors.lastname: Geng
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn.
authors.forename: Wenqin
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Physical Science and Technology, ShanghaiTech University, Shanghai, China 201210. gchen@shanghaitech.edu.cn.
authors.forename: Longlong
authors.initials: L
authors.lastname: Wu
authors.affiliation: School of Physical Science and Technology, ShanghaiTech University, Shanghai, China 201210. gchen@shanghaitech.edu.cn.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Gao
authors.affiliation: School of Physical Science and Technology, ShanghaiTech University, Shanghai, China 201210. gchen@shanghaitech.edu.cn.
authors.forename: Jianing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn.
authors.forename: Lihua
authors.initials: L
authors.lastname: Wang
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn.
authors.forename: Chunhai
authors.initials: C
authors.lastname: Fan
authors.affiliation: Shanghai Synchrotron Radiation Facility, Division of Physical Biology, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China 201204. fchh@sinap.ac.cn and School of Physical Science and Technology, ShanghaiTech University, Shanghai, China 201210. gchen@shanghaitech.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
mesh_terms: D004247:DNA / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures; D012834:Silver
chemical_list: D012834:Silver; D004247:DNA