In-Plate
and On-Plate Structural Control
of Ultra-Stable Gold/Silver Bimetallic Nanoplates as Redox Catalysts,
Nanobuilding Blocks, and Single-Nanoparticle Surface-Enhanced Raman
Scattering Probes
posted on 2016-10-03, 11:33authored byJu-Hwan Oh, Hyunku Shin, Jong Yun Choi, Hee Won Jung, Yeonho Choi, Jae-Seung Lee
Noble
metal bimetallic nanomaterials have attracted a great deal of attention
owing to the strong correlation between their morphology and chemical
and physical properties. Even though the synthetic strategies for
controlling the shapes of monometallic nanomaterials such as gold
(Au) and silver (Ag) are well-developed, limited advances have been
made with Au/Ag bimetallic nanomaterials to date. In this work, we
demonstrate a highly complex in-plate and on-plate structural control
of Au/Ag bimetallic nanoplates (Au/AgBNPLs) in contrast to conventional,
simply structured, 1D and 2D, branched, and polyhedral nanomaterials.
The polymer used in the synthesis of seeds plays a critical role in
controlling the structure of the Au/AgBNPLs. The Au/AgBNPLs exhibit
exceptionally high chemical stability against various chemical etchants
and a versatile catalytic reactivity with biologically and environmentally
relevant chemical species. Significantly, the reversible assembly
formation of the Au/AgBNPLs is demonstrated by carrying out the surface-functionalization
of the materials with thiol DNA, emphasizing the potential applications
of the Au/AgBNPLs in various diagnostic and therapeutic purposes.
Finally, the surface-enhanced Raman scattering (SERS) properties of
the Au/AgBNPLs are experimentally and theoretically investigated,
demonstrating a substantial potential of the Au/AgBNPLs as single-nanoparticle
SERS probes. Electron microscopy, UV–vis spectroscopy, selected
area electron diffraction (SAED), and energy-dispersive X-ray (EDX)
spectroscopy are employed to analyze the structure and composition
of the Au/AgBNPLs at the atomic level.