Microplasma Fabrication of Three-Dimensional Porous Au/Ag Nanostructures on Disposable Strip for the Applications of Surfaced-Enhanced Raman Scattering and Catalysis

摘要

Surface enhance Raman scattering (SERS) has been demonstrated a useful technology for biological and chemical sensing. In general surface plasmonic resonance metals such as Au and Ag have been reported the efficient materials with SERS properties. Recently theoretical and experimental works have suggested that AgAu bimetallic can further provided enhanced SERS properties. The development of simple, effective, and controlled method to fabricate AgAu nanostructures is important for fundamental and commercialization of SERS-based detection. Here we present an one-step fabrication of three-dimensional porous bimetallic Au/Ag nanostrutures deposited on filter paper using microplasmas at ambient conditions. Microscopic characterization indicates that three-dimensional porous Ag/Au-based microstructures composed with Ag/Au nanoparticles with a particle density of ～2000 particles/mm~2 were synthesized and deposited on filter papers in a single microplasma process. MicroRaman study suggests that the as-fabricated Ag/Au porous structures exhibit exceptional SERS properties with a low detection limit for Rhodamine 6G (R6G), and high signal uniformity and stability. Moreover, the as-prepared Ag/Au porous structures can be directly employed for 4-nitrophenol reduction with high catalytic ability. Our work provides a simple method to fabricate three-dimensional porous multi-metal nanostructures.