Selective Deposition of Au onto 40-nm Ag Nanocubes with Excellent Plasmonic Properties and Chemical Stability
Abstract
Silver nanocrystals have received considerable attention owing to their fascinating optical
properties known as localized surface plasmon resonance for applications in surfaceenhanced
Raman scattering (SERS), optical sensing, near-field optical probing, and
biomedical imaging. However, poor chemical and structural stability of Ag element in an
oxidative environment hinders the usefulness of SERS in biological system. In contrast, gold
is well known for its oxide-free surfaces with excellent biocompatibility but it is not an optical
enhancer as efficient as Ag. In this talk, I will use Ag nanocubes with edge length of 40 nm as
an example to demonstrate our success in epitaxial growth of an ultra-thin Au protective layer (~ 0.6 nm in thickness) on the template of nanocubes to improve their stability without
any compromise of the unique plasmonic property of Ag for SERS detection.
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- Nano@Tech Lecture Series [175]