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Download fileSynthesis of Normal and Inverted Gold−Silver Core−Shell Architectures in β-Cyclodextrin and Their Applications in SERS
journal contribution
posted on 26.07.2007, 00:00 authored by Surojit Pande, Sujit Kumar Ghosh, Snigdhamayee Praharaj, Sudipa Panigrahi, Soumen Basu, Subhra Jana, Anjali Pal, Tatsuya Tsukuda, Tarasankar PalBeta-cyclodextrin (β-CD) in alkaline solution has been observed to produce mono- and bimetallic nanoparticles
of silver and gold and to provide in-house stability to both types of particles. Thus, the weak reducing capability
of the β-CD molecule (oxidation occurs at +1.33 V vs Ag/AgCl) and its unique kinetic control over the
evolution of both normal and inverted core−shell bimetallic architectures have been established. The structure
and composition of the bimetallic particles were characterized by UV−visible spectroscopy, transmission
electron microscopy, high-resolution transmission electron microscopy, electron dispersive spectroscopy, and
X-ray photoelectron spectroscopy. Bimetallic core−shell particles containing silver shells have been shown
to provide an elegant SERS-active substrate compared to the corresponding monometallic nanoparticles, and
therefore, they highlight the importance of electronic ligand effects on the enhancement of the Raman signals
of molecular probes on nanostructured metallic surfaces.