title: Flexible membranes of Ag-nanosheet-grafted polyamide-nanofibers as effective 3D SERS substrates.
abstract: We report on a synthetic approach to produce self-supported flexible surface-enhanced Raman scattering (SERS) active membranes consisting of polyamide (PA) nanofibers grafted with vertical Ag-nanosheets, via a combinatorial process of electrospinning PA-nanofiber membranes, assembling Au-nanoparticles on the PA-nanofibers as seeds for subsequent growth of Ag-nanosheets, and electrodepositing Ag-nanosheets on the electrospun PA-nanofibers. As a high density of Ag-nanosheets are vertically grown around each PA-nanofiber in the three-dimensional (3D) networked PA-nanofiber membranes, homogeneous nano-scaled gaps between the neighboring Ag-nanosheets are formed, leading to a high density of 3D SERS "hot spots" within the Ag-nanosheet-grafted PA-nanofiber membranes. The Ag-nanosheet-grafted PA-nanofiber membranes demonstrate high SERS activity with excellent Raman signal reproducibility for rhodamine 6G over the whole membrane. For a SERS-based trial analysis of polychlorinated biphenyls (PCBs, a kind of global environmental hazard), the 3D SERS substrate membranes are modified with mono-6-β-cychlodextrin to effectively capture PCB molecules. As a result, not only a low concentration down to 10(-6) M is reached, but also two congeners of PCBs in their mixed solution are identified, showing promising potential in SERS-based rapid detection of trace organic pollutants such as PCBs in the environment.
authors.affiliation: Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructures, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, China. gwmeng@issp.ac.cn.
authors.forename: Yiwu
authors.initials: Y
authors.lastname: Qian
authors.forename: Guowen
authors.initials: G
authors.lastname: Meng
authors.forename: Qing
authors.initials: Q
authors.lastname: Huang
authors.forename: Chuhong
authors.initials: C
authors.lastname: Zhu
authors.forename: Zhulin
authors.initials: Z
authors.lastname: Huang
authors.forename: Kexi
authors.initials: K
authors.lastname: Sun
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
mesh_terms: D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D049329:Nanostructures / Q000737:chemistry*; D009757:Nylons / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
chemical_list: D009757:Nylons; D012235:Rhodamines; C026188:rhodamine 6G; D012834:Silver