title: Well-organized raspberry-like Ag@Cu bimetal nanoparticles for highly reliable and reproducible surface-enhanced Raman scattering.
abstract: Surface-enhanced Raman scattering (SERS) is ideally suited for probing and mapping surface species and incipient phases on fuel cell electrodes because of its high sensitivity and surface-selectivity, potentially offering insights into the mechanisms of chemical and energy transformation processes. In particular, bimetal nanostructures of coinage metals (Au, Ag, and Cu) have attracted much attention as SERS-active agents due to their distinctive electromagnetic field enhancements originated from surface plasmon resonance. Here we report excellent SERS-active, raspberry-like nanostructures composed of a silver (Ag) nanoparticle core decorated with smaller copper (Cu) nanoparticles, which displayed enhanced and broadened UV-Vis absorption spectra. These unique Ag@Cu raspberry nanostructures enable us to use blue, green, and red light as the excitation laser source for surface-enhanced Raman spectroscopy (SERS) with a large enhancement factor (EF). A highly reliable SERS effect was demonstrated using Rhodamine 6G (R6G) molecules and a thin film of gadolinium doped ceria.
authors.affiliation: School of Materials Science and Engineering, Center for Innovative Fuel Cell and Battery Technologies, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, USA. meilin.liu@mse.gatech.edu.
authors.forename: Jung-Pil
authors.initials: JP
authors.lastname: Lee
authors.forename: Dongchang
authors.initials: D
authors.lastname: Chen
authors.forename: Xiaxi
authors.initials: X
authors.lastname: Li
authors.forename: Seungmin
authors.initials: S
authors.lastname: Yoo
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Bottomley
authors.forename: Mostafa A
authors.initials: MA
authors.lastname: El-Sayed
authors.forename: Soojin
authors.initials: S
authors.lastname: Park
authors.forename: Meilin
authors.initials: M
authors.lastname: Liu