Your browser doesn't support javascript.
loading
Systematic investigation of the SERS efficiency and SERS hotspots in gas-phase deposited Ag nanoparticle assemblies.
He, L B; Wang, Y L; Xie, X; Han, M; Song, F Q; Wang, B J; Cheng, W L; Xu, H X; Sun, L T.
Affiliation
  • He LB; SEU-FEI Nano-Pico Centre, Key Lab of MEMS of Ministry of Education, Southeast University, Nanjing 210096, P. R. China. helongbing@seu.edu.cn slt@seu.edu.cn and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, P. R. China. sjhanmin@nju.edu.cn.
  • Wang YL; SEU-FEI Nano-Pico Centre, Key Lab of MEMS of Ministry of Education, Southeast University, Nanjing 210096, P. R. China. helongbing@seu.edu.cn slt@seu.edu.cn.
  • Xie X; SEU-FEI Nano-Pico Centre, Key Lab of MEMS of Ministry of Education, Southeast University, Nanjing 210096, P. R. China. helongbing@seu.edu.cn slt@seu.edu.cn.
  • Han M; National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, P. R. China. sjhanmin@nju.edu.cn.
  • Song FQ; National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, P. R. China. sjhanmin@nju.edu.cn.
  • Wang BJ; SEU-FEI Nano-Pico Centre, Key Lab of MEMS of Ministry of Education, Southeast University, Nanjing 210096, P. R. China. helongbing@seu.edu.cn slt@seu.edu.cn.
  • Cheng WL; Department of Chemical Engineering, Monash University, Building 36, Clayton, Victoria 3800, Australia.
  • Xu HX; Centre for Nanoscience and Nanotechnology, School of Physics and Technology, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
  • Sun LT; SEU-FEI Nano-Pico Centre, Key Lab of MEMS of Ministry of Education, Southeast University, Nanjing 210096, P. R. China. helongbing@seu.edu.cn slt@seu.edu.cn.
Phys Chem Chem Phys ; 19(7): 5091-5101, 2017 02 15.
Article in En | MEDLINE | ID: mdl-28138663
Gas-phase deposited Ag nanoparticle assemblies are one of the most commonly used plasmonic substrates benefiting from their remarkable advantages such as clean particle surface, tunable particle density, available inter-particle gaps, low-cost and scalable fabrication, and excellent industry compatibility. However, their performance efficiencies are difficult to optimize due to the lack of knowledge of the hotspots inside their structures. We here report a design of delicate rainbow-like Ag nanoparticle assemblies, based on which the hotspots can be revealed through a combinatorial approach. The findings show that the hotspots in gas-phase deposited Ag nanoparticle assemblies are uniquely entangled by the excitation energy and specific inter-particle gaps, differing from the matching conditions in periodic arrays. For Ag nanoparticle assemblies deposited on Formvar-filmed substrates, the mean particle size is maintained around 10 nm, while the particle density can be widely tuned. The one possessing the highest SERS efficiency (under 473 nm excitation) have a particle number density of around 7100 µm-2. Gaps with an inter-particle spacing of around 3 nm are found to serve as SERS hotspots, and these hotspots contribute to 68% of the overall SERS intensity. For Ag nanoparticle assemblies fabricated on carbon-filmed substrates, the mean particle size can be feasibly tuned. The one possessing the highest SERS efficiency under 473 nm excitation has a particle number density of around 460 µm-2 and a mean particle size of around 42.1 nm. The construction of Ag-analyte-Ag sandwich-like nanoparticle assemblies by a two-step-deposition method slightly improves the SERS efficiency when the particle number density is low, but suppresses the SERS efficiency when the particle number density is high.

Full text: 1 Database: MEDLINE Language: En Journal: Phys Chem Chem Phys Journal subject: BIOFISICA / QUIMICA Year: 2017 Type: Article

Full text: 1 Database: MEDLINE Language: En Journal: Phys Chem Chem Phys Journal subject: BIOFISICA / QUIMICA Year: 2017 Type: Article