title: Particle-Film Plasmons on Periodic Silver Film over Nanosphere (AgFON): A Hybrid Plasmonic Nanoarchitecture for Surface-Enhanced Raman Spectroscopy.
abstract: Plasmonic systems based on particle-film plasmonic couplings have recently attracted great attention because of the significantly enhanced electric field at the particle-film gaps. Here, we introduce a hybrid plasmonic architecture utilizing combined plasmonic effects of particle-film gap plasmons and silver film over nanosphere (AgFON) substrates. When gold nanoparticles (AuNPs) are assembled on AgFON substrates with controllable particle-film gap distances, the AuNP-AgFON system supports multiple plasmonic couplings from interparticle, particle-film, and crevice gaps, resulting in a huge surface-enhanced Raman spectroscopy (SERS) effect. We show that the periodicity of AgFON substrates and the particle-film gaps greatly affects the surface plasmon resonances, and thus, the SERS effects due to the interplay between multiple plasmonic couplings. The optimally designed AuNP-AgFON substrate shows a SERS enhancement of 233 times compared to the bare AgFON substrate. The ultrasensitive SERS sensing capability is also demonstrated by detecting glutathione, a neurochemical molecule that is an important antioxidant, down to the 10 pM level.
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science & Technology (UNIST) , Ulsan 44919, Republic of Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Electronic & Computer Engineering, Hong Kong University of Science & Technology (HKUST) , Hong Kong SAR, China.
authors.forename: Qianpeng
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science & Technology (UNIST) , Ulsan 44919, Republic of Korea.
authors.forename: Seungyoung
authors.initials: S
authors.lastname: Park
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science & Technology (UNIST) , Ulsan 44919, Republic of Korea.
authors.forename: Ayoung
authors.initials: A
authors.lastname: Choe
authors.affiliation: Department of Electronic & Computer Engineering, Hong Kong University of Science & Technology (HKUST) , Hong Kong SAR, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Fan
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science & Technology (UNIST) , Ulsan 44919, Republic of Korea.
authors.forename: Hyunhyub
authors.initials: H
authors.lastname: Ko
mesh_terms: D005978:Glutathione / Q000737:chemistry; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D011137:Polystyrenes / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D011137:Polystyrenes; D012834:Silver; D005978:Glutathione
keywords: AgFON; SERS; chemical sensor; particle−film plasmon coupling; surface plasmons