title: Holey Au-Ag alloy nanoplates with built-in hotspots for surface-enhanced Raman scattering.
abstract: Plasmonic noble metal nanocrystals with interior nanogaps have attracted great attention in surface-enhanced Raman scattering (SERS) applications due to the presence of built-in hotspots. Herein, we report a synthesis route to holey Au-Ag alloy nanoplates by controlled galvanic replacement with Ag nanoplates as the sacrificial template, a sulfite-coordinated Au(i) salt as the Au source, and polyvinylpyrrolidone (PVP) as the capping agent. PVP helps regulate the anisotropic growth of nanopores on the Ag nanoplates to afford a highly holey nanostructure, and the monovalent Au(i) salt plays a critical role in stabilizing these holey nanoplates by rapidly enriching Au in the alloy nanostructures. Numerical simulations and experimental results suggest that these holey Au-Ag alloy nanoplates possess enormous internal hotspots for high sensitivity in the SERS analysis, and high stability for excellent reliability of the analysis under many harsh conditions. We believe that this strategy is potentially applicable to the synthesis of many other types of plasmonic nanostructures with inherent nanogaps for many sensing and imaging applications.
authors.affiliation: Center for Materials Chemistry, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China. gaochuanbo@mail.xjtu.edu.cn.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Wei
authors.affiliation: Center for Materials Chemistry, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China. gaochuanbo@mail.xjtu.edu.cn.
authors.forename: Qikui
authors.initials: Q
authors.lastname: Fan
authors.affiliation: Center for Materials Chemistry, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China. gaochuanbo@mail.xjtu.edu.cn.
authors.forename: Hongpo
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Chemistry, University of California, Riverside, California 92521, USA.
authors.forename: Yaocai
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Center for Materials Chemistry, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China. gaochuanbo@mail.xjtu.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, Stockholm 10691, Sweden.
authors.forename: Haoquan
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Chemistry, University of California, Riverside, California 92521, USA.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Center for Materials Chemistry, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China. gaochuanbo@mail.xjtu.edu.cn.
authors.forename: Chuanbo
authors.initials: C
authors.lastname: Gao